diff options
Diffstat (limited to 'security/security.c')
| -rw-r--r-- | security/security.c | 5086 |
1 files changed, 3966 insertions, 1120 deletions
diff --git a/security/security.c b/security/security.c index d1571900a8c7..31a688650601 100644 --- a/security/security.c +++ b/security/security.c @@ -6,6 +6,7 @@ * Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com> * Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com> * Copyright (C) 2016 Mellanox Technologies + * Copyright (C) 2023 Microsoft Corporation <paul@paul-moore.com> */ #define pr_fmt(fmt) "LSM: " fmt @@ -18,22 +19,20 @@ #include <linux/kernel.h> #include <linux/kernel_read_file.h> #include <linux/lsm_hooks.h> -#include <linux/integrity.h> -#include <linux/ima.h> -#include <linux/evm.h> -#include <linux/fsnotify.h> #include <linux/mman.h> #include <linux/mount.h> #include <linux/personality.h> #include <linux/backing-dev.h> #include <linux/string.h> +#include <linux/xattr.h> #include <linux/msg.h> +#include <linux/overflow.h> +#include <linux/perf_event.h> +#include <linux/fs.h> #include <net/flow.h> +#include <net/sock.h> -#define MAX_LSM_EVM_XATTR 2 - -/* How many LSMs were built into the kernel? */ -#define LSM_COUNT (__end_lsm_info - __start_lsm_info) +#include "lsm.h" /* * These are descriptions of the reasons that can be passed to the @@ -41,7 +40,7 @@ * all security modules to use the same descriptions for auditing * purposes. */ -const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = { +const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX + 1] = { [LOCKDOWN_NONE] = "none", [LOCKDOWN_MODULE_SIGNATURE] = "unsigned module loading", [LOCKDOWN_DEV_MEM] = "/dev/mem,kmem,port", @@ -74,554 +73,159 @@ const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = { [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality", }; -struct security_hook_heads security_hook_heads __lsm_ro_after_init; -static BLOCKING_NOTIFIER_HEAD(blocking_lsm_notifier_chain); - -static struct kmem_cache *lsm_file_cache; -static struct kmem_cache *lsm_inode_cache; - -char *lsm_names; -static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init; - -/* Boot-time LSM user choice */ -static __initdata const char *chosen_lsm_order; -static __initdata const char *chosen_major_lsm; - -static __initconst const char * const builtin_lsm_order = CONFIG_LSM; - -/* Ordered list of LSMs to initialize. */ -static __initdata struct lsm_info **ordered_lsms; -static __initdata struct lsm_info *exclusive; - -static __initdata bool debug; -#define init_debug(...) \ - do { \ - if (debug) \ - pr_info(__VA_ARGS__); \ - } while (0) - -static bool __init is_enabled(struct lsm_info *lsm) -{ - if (!lsm->enabled) - return false; - - return *lsm->enabled; -} - -/* Mark an LSM's enabled flag. */ -static int lsm_enabled_true __initdata = 1; -static int lsm_enabled_false __initdata = 0; -static void __init set_enabled(struct lsm_info *lsm, bool enabled) -{ - /* - * When an LSM hasn't configured an enable variable, we can use - * a hard-coded location for storing the default enabled state. - */ - if (!lsm->enabled) { - if (enabled) - lsm->enabled = &lsm_enabled_true; - else - lsm->enabled = &lsm_enabled_false; - } else if (lsm->enabled == &lsm_enabled_true) { - if (!enabled) - lsm->enabled = &lsm_enabled_false; - } else if (lsm->enabled == &lsm_enabled_false) { - if (enabled) - lsm->enabled = &lsm_enabled_true; - } else { - *lsm->enabled = enabled; - } -} - -/* Is an LSM already listed in the ordered LSMs list? */ -static bool __init exists_ordered_lsm(struct lsm_info *lsm) -{ - struct lsm_info **check; - - for (check = ordered_lsms; *check; check++) - if (*check == lsm) - return true; - - return false; -} - -/* Append an LSM to the list of ordered LSMs to initialize. */ -static int last_lsm __initdata; -static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from) -{ - /* Ignore duplicate selections. */ - if (exists_ordered_lsm(lsm)) - return; - - if (WARN(last_lsm == LSM_COUNT, "%s: out of LSM slots!?\n", from)) - return; - - /* Enable this LSM, if it is not already set. */ - if (!lsm->enabled) - lsm->enabled = &lsm_enabled_true; - ordered_lsms[last_lsm++] = lsm; - - init_debug("%s ordered: %s (%s)\n", from, lsm->name, - is_enabled(lsm) ? "enabled" : "disabled"); -} - -/* Is an LSM allowed to be initialized? */ -static bool __init lsm_allowed(struct lsm_info *lsm) -{ - /* Skip if the LSM is disabled. */ - if (!is_enabled(lsm)) - return false; - - /* Not allowed if another exclusive LSM already initialized. */ - if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && exclusive) { - init_debug("exclusive disabled: %s\n", lsm->name); - return false; - } - - return true; -} - -static void __init lsm_set_blob_size(int *need, int *lbs) -{ - int offset; +bool lsm_debug __ro_after_init; - if (*need <= 0) - return; +unsigned int lsm_active_cnt __ro_after_init; +const struct lsm_id *lsm_idlist[MAX_LSM_COUNT]; - offset = ALIGN(*lbs, sizeof(void *)); - *lbs = offset + *need; - *need = offset; -} +struct lsm_blob_sizes blob_sizes; -static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) -{ - if (!needed) - return; +struct kmem_cache *lsm_file_cache; +struct kmem_cache *lsm_inode_cache; - lsm_set_blob_size(&needed->lbs_cred, &blob_sizes.lbs_cred); - lsm_set_blob_size(&needed->lbs_file, &blob_sizes.lbs_file); - /* - * The inode blob gets an rcu_head in addition to - * what the modules might need. - */ - if (needed->lbs_inode && blob_sizes.lbs_inode == 0) - blob_sizes.lbs_inode = sizeof(struct rcu_head); - lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode); - lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc); - lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg); - lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock); - lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task); -} - -/* Prepare LSM for initialization. */ -static void __init prepare_lsm(struct lsm_info *lsm) -{ - int enabled = lsm_allowed(lsm); - - /* Record enablement (to handle any following exclusive LSMs). */ - set_enabled(lsm, enabled); - - /* If enabled, do pre-initialization work. */ - if (enabled) { - if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !exclusive) { - exclusive = lsm; - init_debug("exclusive chosen: %s\n", lsm->name); - } +#define SECURITY_HOOK_ACTIVE_KEY(HOOK, IDX) security_hook_active_##HOOK##_##IDX - lsm_set_blob_sizes(lsm->blobs); - } -} - -/* Initialize a given LSM, if it is enabled. */ -static void __init initialize_lsm(struct lsm_info *lsm) -{ - if (is_enabled(lsm)) { - int ret; - - init_debug("initializing %s\n", lsm->name); - ret = lsm->init(); - WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret); - } -} - -/* Populate ordered LSMs list from comma-separated LSM name list. */ -static void __init ordered_lsm_parse(const char *order, const char *origin) -{ - struct lsm_info *lsm; - char *sep, *name, *next; - - /* LSM_ORDER_FIRST is always first. */ - for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { - if (lsm->order == LSM_ORDER_FIRST) - append_ordered_lsm(lsm, " first"); - } - - /* Process "security=", if given. */ - if (chosen_major_lsm) { - struct lsm_info *major; - - /* - * To match the original "security=" behavior, this - * explicitly does NOT fallback to another Legacy Major - * if the selected one was separately disabled: disable - * all non-matching Legacy Major LSMs. - */ - for (major = __start_lsm_info; major < __end_lsm_info; - major++) { - if ((major->flags & LSM_FLAG_LEGACY_MAJOR) && - strcmp(major->name, chosen_major_lsm) != 0) { - set_enabled(major, false); - init_debug("security=%s disabled: %s (only one legacy major LSM)\n", - chosen_major_lsm, major->name); - } - } - } - - sep = kstrdup(order, GFP_KERNEL); - next = sep; - /* Walk the list, looking for matching LSMs. */ - while ((name = strsep(&next, ",")) != NULL) { - bool found = false; - - for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { - if (lsm->order == LSM_ORDER_MUTABLE && - strcmp(lsm->name, name) == 0) { - append_ordered_lsm(lsm, origin); - found = true; - } - } - - if (!found) - init_debug("%s ignored: %s (not built into kernel)\n", - origin, name); - } - - /* Process "security=", if given. */ - if (chosen_major_lsm) { - for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { - if (exists_ordered_lsm(lsm)) - continue; - if (strcmp(lsm->name, chosen_major_lsm) == 0) - append_ordered_lsm(lsm, "security="); - } - } - - /* Disable all LSMs not in the ordered list. */ - for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { - if (exists_ordered_lsm(lsm)) - continue; - set_enabled(lsm, false); - init_debug("%s skipped: %s (not in requested order)\n", - origin, lsm->name); - } - - kfree(sep); -} - -static void __init lsm_early_cred(struct cred *cred); -static void __init lsm_early_task(struct task_struct *task); - -static int lsm_append(const char *new, char **result); - -static void __init report_lsm_order(void) -{ - struct lsm_info **lsm, *early; - int first = 0; - - pr_info("initializing lsm="); - - /* Report each enabled LSM name, comma separated. */ - for (early = __start_early_lsm_info; early < __end_early_lsm_info; early++) - if (is_enabled(early)) - pr_cont("%s%s", first++ == 0 ? "" : ",", early->name); - for (lsm = ordered_lsms; *lsm; lsm++) - if (is_enabled(*lsm)) - pr_cont("%s%s", first++ == 0 ? "" : ",", (*lsm)->name); - - pr_cont("\n"); -} - -static void __init ordered_lsm_init(void) -{ - struct lsm_info **lsm; - - ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms), - GFP_KERNEL); - - if (chosen_lsm_order) { - if (chosen_major_lsm) { - pr_warn("security=%s is ignored because it is superseded by lsm=%s\n", - chosen_major_lsm, chosen_lsm_order); - chosen_major_lsm = NULL; - } - ordered_lsm_parse(chosen_lsm_order, "cmdline"); - } else - ordered_lsm_parse(builtin_lsm_order, "builtin"); - - for (lsm = ordered_lsms; *lsm; lsm++) - prepare_lsm(*lsm); - - report_lsm_order(); - - init_debug("cred blob size = %d\n", blob_sizes.lbs_cred); - init_debug("file blob size = %d\n", blob_sizes.lbs_file); - init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); - init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); - init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); - init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); - init_debug("task blob size = %d\n", blob_sizes.lbs_task); - - /* - * Create any kmem_caches needed for blobs - */ - if (blob_sizes.lbs_file) - lsm_file_cache = kmem_cache_create("lsm_file_cache", - blob_sizes.lbs_file, 0, - SLAB_PANIC, NULL); - if (blob_sizes.lbs_inode) - lsm_inode_cache = kmem_cache_create("lsm_inode_cache", - blob_sizes.lbs_inode, 0, - SLAB_PANIC, NULL); - - lsm_early_cred((struct cred *) current->cred); - lsm_early_task(current); - for (lsm = ordered_lsms; *lsm; lsm++) - initialize_lsm(*lsm); +/* + * Identifier for the LSM static calls. + * HOOK is an LSM hook as defined in linux/lsm_hookdefs.h + * IDX is the index of the static call. 0 <= NUM < MAX_LSM_COUNT + */ +#define LSM_STATIC_CALL(HOOK, IDX) lsm_static_call_##HOOK##_##IDX - kfree(ordered_lsms); -} +/* + * Call the macro M for each LSM hook MAX_LSM_COUNT times. + */ +#define LSM_LOOP_UNROLL(M, ...) \ +do { \ + UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__) \ +} while (0) + +#define LSM_DEFINE_UNROLL(M, ...) UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__) + +#ifdef CONFIG_HAVE_STATIC_CALL +#define LSM_HOOK_TRAMP(NAME, NUM) \ + &STATIC_CALL_TRAMP(LSM_STATIC_CALL(NAME, NUM)) +#else +#define LSM_HOOK_TRAMP(NAME, NUM) NULL +#endif -int __init early_security_init(void) -{ - struct lsm_info *lsm; +/* + * Define static calls and static keys for each LSM hook. + */ +#define DEFINE_LSM_STATIC_CALL(NUM, NAME, RET, ...) \ + DEFINE_STATIC_CALL_NULL(LSM_STATIC_CALL(NAME, NUM), \ + *((RET(*)(__VA_ARGS__))NULL)); \ + DEFINE_STATIC_KEY_FALSE(SECURITY_HOOK_ACTIVE_KEY(NAME, NUM)); -#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ - INIT_HLIST_HEAD(&security_hook_heads.NAME); -#include "linux/lsm_hook_defs.h" +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + LSM_DEFINE_UNROLL(DEFINE_LSM_STATIC_CALL, NAME, RET, __VA_ARGS__) +#include <linux/lsm_hook_defs.h> #undef LSM_HOOK +#undef DEFINE_LSM_STATIC_CALL - for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) { - if (!lsm->enabled) - lsm->enabled = &lsm_enabled_true; - prepare_lsm(lsm); - initialize_lsm(lsm); - } - - return 0; -} - -/** - * security_init - initializes the security framework +/* + * Initialise a table of static calls for each LSM hook. + * DEFINE_STATIC_CALL_NULL invocation above generates a key (STATIC_CALL_KEY) + * and a trampoline (STATIC_CALL_TRAMP) which are used to call + * __static_call_update when updating the static call. * - * This should be called early in the kernel initialization sequence. + * The static calls table is used by early LSMs, some architectures can fault on + * unaligned accesses and the fault handling code may not be ready by then. + * Thus, the static calls table should be aligned to avoid any unhandled faults + * in early init. */ -int __init security_init(void) -{ - struct lsm_info *lsm; - - init_debug("legacy security=%s\n", chosen_major_lsm ?: " *unspecified*"); - init_debug(" CONFIG_LSM=%s\n", builtin_lsm_order); - init_debug("boot arg lsm=%s\n", chosen_lsm_order ?: " *unspecified*"); - - /* - * Append the names of the early LSM modules now that kmalloc() is - * available - */ - for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) { - init_debug(" early started: %s (%s)\n", lsm->name, - is_enabled(lsm) ? "enabled" : "disabled"); - if (lsm->enabled) - lsm_append(lsm->name, &lsm_names); - } - - /* Load LSMs in specified order. */ - ordered_lsm_init(); - - return 0; -} - -/* Save user chosen LSM */ -static int __init choose_major_lsm(char *str) -{ - chosen_major_lsm = str; - return 1; -} -__setup("security=", choose_major_lsm); - -/* Explicitly choose LSM initialization order. */ -static int __init choose_lsm_order(char *str) -{ - chosen_lsm_order = str; - return 1; -} -__setup("lsm=", choose_lsm_order); - -/* Enable LSM order debugging. */ -static int __init enable_debug(char *str) -{ - debug = true; - return 1; -} -__setup("lsm.debug", enable_debug); - -static bool match_last_lsm(const char *list, const char *lsm) -{ - const char *last; - - if (WARN_ON(!list || !lsm)) - return false; - last = strrchr(list, ','); - if (last) - /* Pass the comma, strcmp() will check for '\0' */ - last++; - else - last = list; - return !strcmp(last, lsm); -} - -static int lsm_append(const char *new, char **result) -{ - char *cp; - - if (*result == NULL) { - *result = kstrdup(new, GFP_KERNEL); - if (*result == NULL) - return -ENOMEM; - } else { - /* Check if it is the last registered name */ - if (match_last_lsm(*result, new)) - return 0; - cp = kasprintf(GFP_KERNEL, "%s,%s", *result, new); - if (cp == NULL) - return -ENOMEM; - kfree(*result); - *result = cp; - } - return 0; -} +struct lsm_static_calls_table + static_calls_table __ro_after_init __aligned(sizeof(u64)) = { +#define INIT_LSM_STATIC_CALL(NUM, NAME) \ + (struct lsm_static_call) { \ + .key = &STATIC_CALL_KEY(LSM_STATIC_CALL(NAME, NUM)), \ + .trampoline = LSM_HOOK_TRAMP(NAME, NUM), \ + .active = &SECURITY_HOOK_ACTIVE_KEY(NAME, NUM), \ + }, +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + .NAME = { \ + LSM_DEFINE_UNROLL(INIT_LSM_STATIC_CALL, NAME) \ + }, +#include <linux/lsm_hook_defs.h> +#undef LSM_HOOK +#undef INIT_LSM_STATIC_CALL + }; /** - * security_add_hooks - Add a modules hooks to the hook lists. - * @hooks: the hooks to add - * @count: the number of hooks to add - * @lsm: the name of the security module + * lsm_file_alloc - allocate a composite file blob + * @file: the file that needs a blob * - * Each LSM has to register its hooks with the infrastructure. + * Allocate the file blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. */ -void __init security_add_hooks(struct security_hook_list *hooks, int count, - const char *lsm) +static int lsm_file_alloc(struct file *file) { - int i; - - for (i = 0; i < count; i++) { - hooks[i].lsm = lsm; - hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); - } - - /* - * Don't try to append during early_security_init(), we'll come back - * and fix this up afterwards. - */ - if (slab_is_available()) { - if (lsm_append(lsm, &lsm_names) < 0) - panic("%s - Cannot get early memory.\n", __func__); + if (!lsm_file_cache) { + file->f_security = NULL; + return 0; } -} -int call_blocking_lsm_notifier(enum lsm_event event, void *data) -{ - return blocking_notifier_call_chain(&blocking_lsm_notifier_chain, - event, data); -} -EXPORT_SYMBOL(call_blocking_lsm_notifier); - -int register_blocking_lsm_notifier(struct notifier_block *nb) -{ - return blocking_notifier_chain_register(&blocking_lsm_notifier_chain, - nb); -} -EXPORT_SYMBOL(register_blocking_lsm_notifier); - -int unregister_blocking_lsm_notifier(struct notifier_block *nb) -{ - return blocking_notifier_chain_unregister(&blocking_lsm_notifier_chain, - nb); + file->f_security = kmem_cache_zalloc(lsm_file_cache, GFP_KERNEL); + if (file->f_security == NULL) + return -ENOMEM; + return 0; } -EXPORT_SYMBOL(unregister_blocking_lsm_notifier); /** - * lsm_cred_alloc - allocate a composite cred blob - * @cred: the cred that needs a blob + * lsm_blob_alloc - allocate a composite blob + * @dest: the destination for the blob + * @size: the size of the blob * @gfp: allocation type * - * Allocate the cred blob for all the modules + * Allocate a blob for all the modules * * Returns 0, or -ENOMEM if memory can't be allocated. */ -static int lsm_cred_alloc(struct cred *cred, gfp_t gfp) +static int lsm_blob_alloc(void **dest, size_t size, gfp_t gfp) { - if (blob_sizes.lbs_cred == 0) { - cred->security = NULL; + if (size == 0) { + *dest = NULL; return 0; } - cred->security = kzalloc(blob_sizes.lbs_cred, gfp); - if (cred->security == NULL) + *dest = kzalloc(size, gfp); + if (*dest == NULL) return -ENOMEM; return 0; } /** - * lsm_early_cred - during initialization allocate a composite cred blob + * lsm_cred_alloc - allocate a composite cred blob * @cred: the cred that needs a blob + * @gfp: allocation type * * Allocate the cred blob for all the modules - */ -static void __init lsm_early_cred(struct cred *cred) -{ - int rc = lsm_cred_alloc(cred, GFP_KERNEL); - - if (rc) - panic("%s: Early cred alloc failed.\n", __func__); -} - -/** - * lsm_file_alloc - allocate a composite file blob - * @file: the file that needs a blob - * - * Allocate the file blob for all the modules * * Returns 0, or -ENOMEM if memory can't be allocated. */ -static int lsm_file_alloc(struct file *file) +int lsm_cred_alloc(struct cred *cred, gfp_t gfp) { - if (!lsm_file_cache) { - file->f_security = NULL; - return 0; - } - - file->f_security = kmem_cache_zalloc(lsm_file_cache, GFP_KERNEL); - if (file->f_security == NULL) - return -ENOMEM; - return 0; + return lsm_blob_alloc(&cred->security, blob_sizes.lbs_cred, gfp); } /** * lsm_inode_alloc - allocate a composite inode blob * @inode: the inode that needs a blob + * @gfp: allocation flags * * Allocate the inode blob for all the modules * * Returns 0, or -ENOMEM if memory can't be allocated. */ -int lsm_inode_alloc(struct inode *inode) +static int lsm_inode_alloc(struct inode *inode, gfp_t gfp) { if (!lsm_inode_cache) { inode->i_security = NULL; return 0; } - inode->i_security = kmem_cache_zalloc(lsm_inode_cache, GFP_NOFS); + inode->i_security = kmem_cache_zalloc(lsm_inode_cache, gfp); if (inode->i_security == NULL) return -ENOMEM; return 0; @@ -635,17 +239,9 @@ int lsm_inode_alloc(struct inode *inode) * * Returns 0, or -ENOMEM if memory can't be allocated. */ -static int lsm_task_alloc(struct task_struct *task) +int lsm_task_alloc(struct task_struct *task) { - if (blob_sizes.lbs_task == 0) { - task->security = NULL; - return 0; - } - - task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL); - if (task->security == NULL) - return -ENOMEM; - return 0; + return lsm_blob_alloc(&task->security, blob_sizes.lbs_task, GFP_KERNEL); } /** @@ -658,16 +254,23 @@ static int lsm_task_alloc(struct task_struct *task) */ static int lsm_ipc_alloc(struct kern_ipc_perm *kip) { - if (blob_sizes.lbs_ipc == 0) { - kip->security = NULL; - return 0; - } + return lsm_blob_alloc(&kip->security, blob_sizes.lbs_ipc, GFP_KERNEL); +} - kip->security = kzalloc(blob_sizes.lbs_ipc, GFP_KERNEL); - if (kip->security == NULL) - return -ENOMEM; - return 0; +#ifdef CONFIG_KEYS +/** + * lsm_key_alloc - allocate a composite key blob + * @key: the key that needs a blob + * + * Allocate the key blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_key_alloc(struct key *key) +{ + return lsm_blob_alloc(&key->security, blob_sizes.lbs_key, GFP_KERNEL); } +#endif /* CONFIG_KEYS */ /** * lsm_msg_msg_alloc - allocate a composite msg_msg blob @@ -679,32 +282,66 @@ static int lsm_ipc_alloc(struct kern_ipc_perm *kip) */ static int lsm_msg_msg_alloc(struct msg_msg *mp) { - if (blob_sizes.lbs_msg_msg == 0) { - mp->security = NULL; - return 0; - } + return lsm_blob_alloc(&mp->security, blob_sizes.lbs_msg_msg, + GFP_KERNEL); +} - mp->security = kzalloc(blob_sizes.lbs_msg_msg, GFP_KERNEL); - if (mp->security == NULL) - return -ENOMEM; - return 0; +/** + * lsm_bdev_alloc - allocate a composite block_device blob + * @bdev: the block_device that needs a blob + * + * Allocate the block_device blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_bdev_alloc(struct block_device *bdev) +{ + return lsm_blob_alloc(&bdev->bd_security, blob_sizes.lbs_bdev, + GFP_KERNEL); } +#ifdef CONFIG_BPF_SYSCALL /** - * lsm_early_task - during initialization allocate a composite task blob - * @task: the task that needs a blob + * lsm_bpf_map_alloc - allocate a composite bpf_map blob + * @map: the bpf_map that needs a blob * - * Allocate the task blob for all the modules + * Allocate the bpf_map blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. */ -static void __init lsm_early_task(struct task_struct *task) +static int lsm_bpf_map_alloc(struct bpf_map *map) { - int rc = lsm_task_alloc(task); + return lsm_blob_alloc(&map->security, blob_sizes.lbs_bpf_map, GFP_KERNEL); +} - if (rc) - panic("%s: Early task alloc failed.\n", __func__); +/** + * lsm_bpf_prog_alloc - allocate a composite bpf_prog blob + * @prog: the bpf_prog that needs a blob + * + * Allocate the bpf_prog blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_bpf_prog_alloc(struct bpf_prog *prog) +{ + return lsm_blob_alloc(&prog->aux->security, blob_sizes.lbs_bpf_prog, GFP_KERNEL); } /** + * lsm_bpf_token_alloc - allocate a composite bpf_token blob + * @token: the bpf_token that needs a blob + * + * Allocate the bpf_token blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_bpf_token_alloc(struct bpf_token *token) +{ + return lsm_blob_alloc(&token->security, blob_sizes.lbs_bpf_token, GFP_KERNEL); +} +#endif /* CONFIG_BPF_SYSCALL */ + +/** * lsm_superblock_alloc - allocate a composite superblock blob * @sb: the superblock that needs a blob * @@ -714,15 +351,62 @@ static void __init lsm_early_task(struct task_struct *task) */ static int lsm_superblock_alloc(struct super_block *sb) { - if (blob_sizes.lbs_superblock == 0) { - sb->s_security = NULL; - return 0; + return lsm_blob_alloc(&sb->s_security, blob_sizes.lbs_superblock, + GFP_KERNEL); +} + +/** + * lsm_fill_user_ctx - Fill a user space lsm_ctx structure + * @uctx: a userspace LSM context to be filled + * @uctx_len: available uctx size (input), used uctx size (output) + * @val: the new LSM context value + * @val_len: the size of the new LSM context value + * @id: LSM id + * @flags: LSM defined flags + * + * Fill all of the fields in a userspace lsm_ctx structure. If @uctx is NULL + * simply calculate the required size to output via @utc_len and return + * success. + * + * Returns 0 on success, -E2BIG if userspace buffer is not large enough, + * -EFAULT on a copyout error, -ENOMEM if memory can't be allocated. + */ +int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, u32 *uctx_len, + void *val, size_t val_len, + u64 id, u64 flags) +{ + struct lsm_ctx *nctx = NULL; + size_t nctx_len; + int rc = 0; + + nctx_len = ALIGN(struct_size(nctx, ctx, val_len), sizeof(void *)); + if (nctx_len > *uctx_len) { + rc = -E2BIG; + goto out; } - sb->s_security = kzalloc(blob_sizes.lbs_superblock, GFP_KERNEL); - if (sb->s_security == NULL) - return -ENOMEM; - return 0; + /* no buffer - return success/0 and set @uctx_len to the req size */ + if (!uctx) + goto out; + + nctx = kzalloc(nctx_len, GFP_KERNEL); + if (nctx == NULL) { + rc = -ENOMEM; + goto out; + } + nctx->id = id; + nctx->flags = flags; + nctx->len = nctx_len; + nctx->ctx_len = val_len; + memcpy(nctx->ctx, val, val_len); + + if (copy_to_user(uctx, nctx, nctx_len)) + rc = -EFAULT; + +out: + kfree(nctx); + *uctx_len = nctx_len; + return rc; } /* @@ -753,126 +437,290 @@ static int lsm_superblock_alloc(struct super_block *sb) * call_int_hook: * This is a hook that returns a value. */ - -#define call_void_hook(FUNC, ...) \ - do { \ - struct security_hook_list *P; \ - \ - hlist_for_each_entry(P, &security_hook_heads.FUNC, list) \ - P->hook.FUNC(__VA_ARGS__); \ +#define __CALL_STATIC_VOID(NUM, HOOK, ...) \ +do { \ + if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \ + static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \ + } \ +} while (0); + +#define call_void_hook(HOOK, ...) \ + do { \ + LSM_LOOP_UNROLL(__CALL_STATIC_VOID, HOOK, __VA_ARGS__); \ } while (0) -#define call_int_hook(FUNC, IRC, ...) ({ \ - int RC = IRC; \ - do { \ - struct security_hook_list *P; \ - \ - hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \ - RC = P->hook.FUNC(__VA_ARGS__); \ - if (RC != 0) \ - break; \ - } \ - } while (0); \ - RC; \ + +#define __CALL_STATIC_INT(NUM, R, HOOK, LABEL, ...) \ +do { \ + if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \ + R = static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \ + if (R != LSM_RET_DEFAULT(HOOK)) \ + goto LABEL; \ + } \ +} while (0); + +#define call_int_hook(HOOK, ...) \ +({ \ + __label__ OUT; \ + int RC = LSM_RET_DEFAULT(HOOK); \ + \ + LSM_LOOP_UNROLL(__CALL_STATIC_INT, RC, HOOK, OUT, __VA_ARGS__); \ +OUT: \ + RC; \ }) +#define lsm_for_each_hook(scall, NAME) \ + for (scall = static_calls_table.NAME; \ + scall - static_calls_table.NAME < MAX_LSM_COUNT; scall++) \ + if (static_key_enabled(&scall->active->key)) + /* Security operations */ +/** + * security_binder_set_context_mgr() - Check if becoming binder ctx mgr is ok + * @mgr: task credentials of current binder process + * + * Check whether @mgr is allowed to be the binder context manager. + * + * Return: Return 0 if permission is granted. + */ int security_binder_set_context_mgr(const struct cred *mgr) { - return call_int_hook(binder_set_context_mgr, 0, mgr); + return call_int_hook(binder_set_context_mgr, mgr); } +/** + * security_binder_transaction() - Check if a binder transaction is allowed + * @from: sending process + * @to: receiving process + * + * Check whether @from is allowed to invoke a binder transaction call to @to. + * + * Return: Returns 0 if permission is granted. + */ int security_binder_transaction(const struct cred *from, const struct cred *to) { - return call_int_hook(binder_transaction, 0, from, to); + return call_int_hook(binder_transaction, from, to); } +/** + * security_binder_transfer_binder() - Check if a binder transfer is allowed + * @from: sending process + * @to: receiving process + * + * Check whether @from is allowed to transfer a binder reference to @to. + * + * Return: Returns 0 if permission is granted. + */ int security_binder_transfer_binder(const struct cred *from, const struct cred *to) { - return call_int_hook(binder_transfer_binder, 0, from, to); + return call_int_hook(binder_transfer_binder, from, to); } +/** + * security_binder_transfer_file() - Check if a binder file xfer is allowed + * @from: sending process + * @to: receiving process + * @file: file being transferred + * + * Check whether @from is allowed to transfer @file to @to. + * + * Return: Returns 0 if permission is granted. + */ int security_binder_transfer_file(const struct cred *from, - const struct cred *to, struct file *file) + const struct cred *to, const struct file *file) { - return call_int_hook(binder_transfer_file, 0, from, to, file); + return call_int_hook(binder_transfer_file, from, to, file); } +/** + * security_ptrace_access_check() - Check if tracing is allowed + * @child: target process + * @mode: PTRACE_MODE flags + * + * Check permission before allowing the current process to trace the @child + * process. Security modules may also want to perform a process tracing check + * during an execve in the set_security or apply_creds hooks of tracing check + * during an execve in the bprm_set_creds hook of binprm_security_ops if the + * process is being traced and its security attributes would be changed by the + * execve. + * + * Return: Returns 0 if permission is granted. + */ int security_ptrace_access_check(struct task_struct *child, unsigned int mode) { - return call_int_hook(ptrace_access_check, 0, child, mode); + return call_int_hook(ptrace_access_check, child, mode); } +/** + * security_ptrace_traceme() - Check if tracing is allowed + * @parent: tracing process + * + * Check that the @parent process has sufficient permission to trace the + * current process before allowing the current process to present itself to the + * @parent process for tracing. + * + * Return: Returns 0 if permission is granted. + */ int security_ptrace_traceme(struct task_struct *parent) { - return call_int_hook(ptrace_traceme, 0, parent); + return call_int_hook(ptrace_traceme, parent); } -int security_capget(struct task_struct *target, - kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) +/** + * security_capget() - Get the capability sets for a process + * @target: target process + * @effective: effective capability set + * @inheritable: inheritable capability set + * @permitted: permitted capability set + * + * Get the @effective, @inheritable, and @permitted capability sets for the + * @target process. The hook may also perform permission checking to determine + * if the current process is allowed to see the capability sets of the @target + * process. + * + * Return: Returns 0 if the capability sets were successfully obtained. + */ +int security_capget(const struct task_struct *target, + kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) { - return call_int_hook(capget, 0, target, - effective, inheritable, permitted); + return call_int_hook(capget, target, effective, inheritable, permitted); } +/** + * security_capset() - Set the capability sets for a process + * @new: new credentials for the target process + * @old: current credentials of the target process + * @effective: effective capability set + * @inheritable: inheritable capability set + * @permitted: permitted capability set + * + * Set the @effective, @inheritable, and @permitted capability sets for the + * current process. + * + * Return: Returns 0 and update @new if permission is granted. + */ int security_capset(struct cred *new, const struct cred *old, const kernel_cap_t *effective, const kernel_cap_t *inheritable, const kernel_cap_t *permitted) { - return call_int_hook(capset, 0, new, old, - effective, inheritable, permitted); + return call_int_hook(capset, new, old, effective, inheritable, + permitted); } +/** + * security_capable() - Check if a process has the necessary capability + * @cred: credentials to examine + * @ns: user namespace + * @cap: capability requested + * @opts: capability check options + * + * Check whether the @tsk process has the @cap capability in the indicated + * credentials. @cap contains the capability <include/linux/capability.h>. + * @opts contains options for the capable check <include/linux/security.h>. + * + * Return: Returns 0 if the capability is granted. + */ int security_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts) { - return call_int_hook(capable, 0, cred, ns, cap, opts); + return call_int_hook(capable, cred, ns, cap, opts); } -int security_quotactl(int cmds, int type, int id, struct super_block *sb) +/** + * security_quotactl() - Check if a quotactl() syscall is allowed for this fs + * @cmds: commands + * @type: type + * @id: id + * @sb: filesystem + * + * Check whether the quotactl syscall is allowed for this @sb. + * + * Return: Returns 0 if permission is granted. + */ +int security_quotactl(int cmds, int type, int id, const struct super_block *sb) { - return call_int_hook(quotactl, 0, cmds, type, id, sb); + return call_int_hook(quotactl, cmds, type, id, sb); } +/** + * security_quota_on() - Check if QUOTAON is allowed for a dentry + * @dentry: dentry + * + * Check whether QUOTAON is allowed for @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_quota_on(struct dentry *dentry) { - return call_int_hook(quota_on, 0, dentry); + return call_int_hook(quota_on, dentry); } +/** + * security_syslog() - Check if accessing the kernel message ring is allowed + * @type: SYSLOG_ACTION_* type + * + * Check permission before accessing the kernel message ring or changing + * logging to the console. See the syslog(2) manual page for an explanation of + * the @type values. + * + * Return: Return 0 if permission is granted. + */ int security_syslog(int type) { - return call_int_hook(syslog, 0, type); + return call_int_hook(syslog, type); } +/** + * security_settime64() - Check if changing the system time is allowed + * @ts: new time + * @tz: timezone + * + * Check permission to change the system time, struct timespec64 is defined in + * <include/linux/time64.h> and timezone is defined in <include/linux/time.h>. + * + * Return: Returns 0 if permission is granted. + */ int security_settime64(const struct timespec64 *ts, const struct timezone *tz) { - return call_int_hook(settime, 0, ts, tz); + return call_int_hook(settime, ts, tz); } +/** + * security_vm_enough_memory_mm() - Check if allocating a new mem map is allowed + * @mm: mm struct + * @pages: number of pages + * + * Check permissions for allocating a new virtual mapping. If all LSMs return + * a positive value, __vm_enough_memory() will be called with cap_sys_admin + * set. If at least one LSM returns 0 or negative, __vm_enough_memory() will be + * called with cap_sys_admin cleared. + * + * Return: Returns 0 if permission is granted by the LSM infrastructure to the + * caller. + */ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) { - struct security_hook_list *hp; + struct lsm_static_call *scall; int cap_sys_admin = 1; int rc; /* - * The module will respond with a positive value if - * it thinks the __vm_enough_memory() call should be - * made with the cap_sys_admin set. If all of the modules - * agree that it should be set it will. If any module - * thinks it should not be set it won't. + * The module will respond with 0 if it thinks the __vm_enough_memory() + * call should be made with the cap_sys_admin set. If all of the modules + * agree that it should be set it will. If any module thinks it should + * not be set it won't. */ - hlist_for_each_entry(hp, &security_hook_heads.vm_enough_memory, list) { - rc = hp->hook.vm_enough_memory(mm, pages); - if (rc <= 0) { + lsm_for_each_hook(scall, vm_enough_memory) { + rc = scall->hl->hook.vm_enough_memory(mm, pages); + if (rc < 0) { cap_sys_admin = 0; break; } @@ -880,51 +728,156 @@ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) return __vm_enough_memory(mm, pages, cap_sys_admin); } +/** + * security_bprm_creds_for_exec() - Prepare the credentials for exec() + * @bprm: binary program information + * + * If the setup in prepare_exec_creds did not setup @bprm->cred->security + * properly for executing @bprm->file, update the LSM's portion of + * @bprm->cred->security to be what commit_creds needs to install for the new + * program. This hook may also optionally check permissions (e.g. for + * transitions between security domains). The hook must set @bprm->secureexec + * to 1 if AT_SECURE should be set to request libc enable secure mode. @bprm + * contains the linux_binprm structure. + * + * If execveat(2) is called with the AT_EXECVE_CHECK flag, bprm->is_check is + * set. The result must be the same as without this flag even if the execution + * will never really happen and @bprm will always be dropped. + * + * This hook must not change current->cred, only @bprm->cred. + * + * Return: Returns 0 if the hook is successful and permission is granted. + */ int security_bprm_creds_for_exec(struct linux_binprm *bprm) { - return call_int_hook(bprm_creds_for_exec, 0, bprm); + return call_int_hook(bprm_creds_for_exec, bprm); } -int security_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file) +/** + * security_bprm_creds_from_file() - Update linux_binprm creds based on file + * @bprm: binary program information + * @file: associated file + * + * If @file is setpcap, suid, sgid or otherwise marked to change privilege upon + * exec, update @bprm->cred to reflect that change. This is called after + * finding the binary that will be executed without an interpreter. This + * ensures that the credentials will not be derived from a script that the + * binary will need to reopen, which when reopend may end up being a completely + * different file. This hook may also optionally check permissions (e.g. for + * transitions between security domains). The hook must set @bprm->secureexec + * to 1 if AT_SECURE should be set to request libc enable secure mode. The + * hook must add to @bprm->per_clear any personality flags that should be + * cleared from current->personality. @bprm contains the linux_binprm + * structure. + * + * Return: Returns 0 if the hook is successful and permission is granted. + */ +int security_bprm_creds_from_file(struct linux_binprm *bprm, const struct file *file) { - return call_int_hook(bprm_creds_from_file, 0, bprm, file); + return call_int_hook(bprm_creds_from_file, bprm, file); } +/** + * security_bprm_check() - Mediate binary handler search + * @bprm: binary program information + * + * This hook mediates the point when a search for a binary handler will begin. + * It allows a check against the @bprm->cred->security value which was set in + * the preceding creds_for_exec call. The argv list and envp list are reliably + * available in @bprm. This hook may be called multiple times during a single + * execve. @bprm contains the linux_binprm structure. + * + * Return: Returns 0 if the hook is successful and permission is granted. + */ int security_bprm_check(struct linux_binprm *bprm) { - int ret; - - ret = call_int_hook(bprm_check_security, 0, bprm); - if (ret) - return ret; - return ima_bprm_check(bprm); + return call_int_hook(bprm_check_security, bprm); } -void security_bprm_committing_creds(struct linux_binprm *bprm) +/** + * security_bprm_committing_creds() - Install creds for a process during exec() + * @bprm: binary program information + * + * Prepare to install the new security attributes of a process being + * transformed by an execve operation, based on the old credentials pointed to + * by @current->cred and the information set in @bprm->cred by the + * bprm_creds_for_exec hook. @bprm points to the linux_binprm structure. This + * hook is a good place to perform state changes on the process such as closing + * open file descriptors to which access will no longer be granted when the + * attributes are changed. This is called immediately before commit_creds(). + */ +void security_bprm_committing_creds(const struct linux_binprm *bprm) { call_void_hook(bprm_committing_creds, bprm); } -void security_bprm_committed_creds(struct linux_binprm *bprm) +/** + * security_bprm_committed_creds() - Tidy up after cred install during exec() + * @bprm: binary program information + * + * Tidy up after the installation of the new security attributes of a process + * being transformed by an execve operation. The new credentials have, by this + * point, been set to @current->cred. @bprm points to the linux_binprm + * structure. This hook is a good place to perform state changes on the + * process such as clearing out non-inheritable signal state. This is called + * immediately after commit_creds(). + */ +void security_bprm_committed_creds(const struct linux_binprm *bprm) { call_void_hook(bprm_committed_creds, bprm); } +/** + * security_fs_context_submount() - Initialise fc->security + * @fc: new filesystem context + * @reference: dentry reference for submount/remount + * + * Fill out the ->security field for a new fs_context. + * + * Return: Returns 0 on success or negative error code on failure. + */ +int security_fs_context_submount(struct fs_context *fc, struct super_block *reference) +{ + return call_int_hook(fs_context_submount, fc, reference); +} + +/** + * security_fs_context_dup() - Duplicate a fs_context LSM blob + * @fc: destination filesystem context + * @src_fc: source filesystem context + * + * Allocate and attach a security structure to sc->security. This pointer is + * initialised to NULL by the caller. @fc indicates the new filesystem context. + * @src_fc indicates the original filesystem context. + * + * Return: Returns 0 on success or a negative error code on failure. + */ int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) { - return call_int_hook(fs_context_dup, 0, fc, src_fc); + return call_int_hook(fs_context_dup, fc, src_fc); } +/** + * security_fs_context_parse_param() - Configure a filesystem context + * @fc: filesystem context + * @param: filesystem parameter + * + * Userspace provided a parameter to configure a superblock. The LSM can + * consume the parameter or return it to the caller for use elsewhere. + * + * Return: If the parameter is used by the LSM it should return 0, if it is + * returned to the caller -ENOPARAM is returned, otherwise a negative + * error code is returned. + */ int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param) { - struct security_hook_list *hp; + struct lsm_static_call *scall; int trc; int rc = -ENOPARAM; - hlist_for_each_entry(hp, &security_hook_heads.fs_context_parse_param, - list) { - trc = hp->hook.fs_context_parse_param(fc, param); + lsm_for_each_hook(scall, fs_context_parse_param) { + trc = scall->hl->hook.fs_context_parse_param(fc, param); if (trc == 0) rc = 0; else if (trc != -ENOPARAM) @@ -933,23 +886,47 @@ int security_fs_context_parse_param(struct fs_context *fc, return rc; } +/** + * security_sb_alloc() - Allocate a super_block LSM blob + * @sb: filesystem superblock + * + * Allocate and attach a security structure to the sb->s_security field. The + * s_security field is initialized to NULL when the structure is allocated. + * @sb contains the super_block structure to be modified. + * + * Return: Returns 0 if operation was successful. + */ int security_sb_alloc(struct super_block *sb) { int rc = lsm_superblock_alloc(sb); if (unlikely(rc)) return rc; - rc = call_int_hook(sb_alloc_security, 0, sb); + rc = call_int_hook(sb_alloc_security, sb); if (unlikely(rc)) security_sb_free(sb); return rc; } +/** + * security_sb_delete() - Release super_block LSM associated objects + * @sb: filesystem superblock + * + * Release objects tied to a superblock (e.g. inodes). @sb contains the + * super_block structure being released. + */ void security_sb_delete(struct super_block *sb) { call_void_hook(sb_delete, sb); } +/** + * security_sb_free() - Free a super_block LSM blob + * @sb: filesystem superblock + * + * Deallocate and clear the sb->s_security field. @sb contains the super_block + * structure to be modified. + */ void security_sb_free(struct super_block *sb) { call_void_hook(sb_free_security, sb); @@ -957,6 +934,12 @@ void security_sb_free(struct super_block *sb) sb->s_security = NULL; } +/** + * security_free_mnt_opts() - Free memory associated with mount options + * @mnt_opts: LSM processed mount options + * + * Free memory associated with @mnt_ops. + */ void security_free_mnt_opts(void **mnt_opts) { if (!*mnt_opts) @@ -966,96 +949,248 @@ void security_free_mnt_opts(void **mnt_opts) } EXPORT_SYMBOL(security_free_mnt_opts); +/** + * security_sb_eat_lsm_opts() - Consume LSM mount options + * @options: mount options + * @mnt_opts: LSM processed mount options + * + * Eat (scan @options) and save them in @mnt_opts. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_sb_eat_lsm_opts(char *options, void **mnt_opts) { - return call_int_hook(sb_eat_lsm_opts, 0, options, mnt_opts); + return call_int_hook(sb_eat_lsm_opts, options, mnt_opts); } EXPORT_SYMBOL(security_sb_eat_lsm_opts); +/** + * security_sb_mnt_opts_compat() - Check if new mount options are allowed + * @sb: filesystem superblock + * @mnt_opts: new mount options + * + * Determine if the new mount options in @mnt_opts are allowed given the + * existing mounted filesystem at @sb. @sb superblock being compared. + * + * Return: Returns 0 if options are compatible. + */ int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts) { - return call_int_hook(sb_mnt_opts_compat, 0, sb, mnt_opts); + return call_int_hook(sb_mnt_opts_compat, sb, mnt_opts); } EXPORT_SYMBOL(security_sb_mnt_opts_compat); +/** + * security_sb_remount() - Verify no incompatible mount changes during remount + * @sb: filesystem superblock + * @mnt_opts: (re)mount options + * + * Extracts security system specific mount options and verifies no changes are + * being made to those options. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_remount(struct super_block *sb, void *mnt_opts) { - return call_int_hook(sb_remount, 0, sb, mnt_opts); + return call_int_hook(sb_remount, sb, mnt_opts); } EXPORT_SYMBOL(security_sb_remount); -int security_sb_kern_mount(struct super_block *sb) +/** + * security_sb_kern_mount() - Check if a kernel mount is allowed + * @sb: filesystem superblock + * + * Mount this @sb if allowed by permissions. + * + * Return: Returns 0 if permission is granted. + */ +int security_sb_kern_mount(const struct super_block *sb) { - return call_int_hook(sb_kern_mount, 0, sb); + return call_int_hook(sb_kern_mount, sb); } +/** + * security_sb_show_options() - Output the mount options for a superblock + * @m: output file + * @sb: filesystem superblock + * + * Show (print on @m) mount options for this @sb. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_sb_show_options(struct seq_file *m, struct super_block *sb) { - return call_int_hook(sb_show_options, 0, m, sb); + return call_int_hook(sb_show_options, m, sb); } +/** + * security_sb_statfs() - Check if accessing fs stats is allowed + * @dentry: superblock handle + * + * Check permission before obtaining filesystem statistics for the @mnt + * mountpoint. @dentry is a handle on the superblock for the filesystem. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_statfs(struct dentry *dentry) { - return call_int_hook(sb_statfs, 0, dentry); + return call_int_hook(sb_statfs, dentry); } +/** + * security_sb_mount() - Check permission for mounting a filesystem + * @dev_name: filesystem backing device + * @path: mount point + * @type: filesystem type + * @flags: mount flags + * @data: filesystem specific data + * + * Check permission before an object specified by @dev_name is mounted on the + * mount point named by @nd. For an ordinary mount, @dev_name identifies a + * device if the file system type requires a device. For a remount + * (@flags & MS_REMOUNT), @dev_name is irrelevant. For a loopback/bind mount + * (@flags & MS_BIND), @dev_name identifies the pathname of the object being + * mounted. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_mount(const char *dev_name, const struct path *path, - const char *type, unsigned long flags, void *data) + const char *type, unsigned long flags, void *data) { - return call_int_hook(sb_mount, 0, dev_name, path, type, flags, data); + return call_int_hook(sb_mount, dev_name, path, type, flags, data); } +/** + * security_sb_umount() - Check permission for unmounting a filesystem + * @mnt: mounted filesystem + * @flags: unmount flags + * + * Check permission before the @mnt file system is unmounted. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_umount(struct vfsmount *mnt, int flags) { - return call_int_hook(sb_umount, 0, mnt, flags); + return call_int_hook(sb_umount, mnt, flags); } -int security_sb_pivotroot(const struct path *old_path, const struct path *new_path) +/** + * security_sb_pivotroot() - Check permissions for pivoting the rootfs + * @old_path: new location for current rootfs + * @new_path: location of the new rootfs + * + * Check permission before pivoting the root filesystem. + * + * Return: Returns 0 if permission is granted. + */ +int security_sb_pivotroot(const struct path *old_path, + const struct path *new_path) { - return call_int_hook(sb_pivotroot, 0, old_path, new_path); + return call_int_hook(sb_pivotroot, old_path, new_path); } +/** + * security_sb_set_mnt_opts() - Set the mount options for a filesystem + * @sb: filesystem superblock + * @mnt_opts: binary mount options + * @kern_flags: kernel flags (in) + * @set_kern_flags: kernel flags (out) + * + * Set the security relevant mount options used for a superblock. + * + * Return: Returns 0 on success, error on failure. + */ int security_sb_set_mnt_opts(struct super_block *sb, - void *mnt_opts, - unsigned long kern_flags, - unsigned long *set_kern_flags) + void *mnt_opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) { - return call_int_hook(sb_set_mnt_opts, - mnt_opts ? -EOPNOTSUPP : 0, sb, - mnt_opts, kern_flags, set_kern_flags); + struct lsm_static_call *scall; + int rc = mnt_opts ? -EOPNOTSUPP : LSM_RET_DEFAULT(sb_set_mnt_opts); + + lsm_for_each_hook(scall, sb_set_mnt_opts) { + rc = scall->hl->hook.sb_set_mnt_opts(sb, mnt_opts, kern_flags, + set_kern_flags); + if (rc != LSM_RET_DEFAULT(sb_set_mnt_opts)) + break; + } + return rc; } EXPORT_SYMBOL(security_sb_set_mnt_opts); +/** + * security_sb_clone_mnt_opts() - Duplicate superblock mount options + * @oldsb: source superblock + * @newsb: destination superblock + * @kern_flags: kernel flags (in) + * @set_kern_flags: kernel flags (out) + * + * Copy all security options from a given superblock to another. + * + * Return: Returns 0 on success, error on failure. + */ int security_sb_clone_mnt_opts(const struct super_block *oldsb, - struct super_block *newsb, - unsigned long kern_flags, - unsigned long *set_kern_flags) + struct super_block *newsb, + unsigned long kern_flags, + unsigned long *set_kern_flags) { - return call_int_hook(sb_clone_mnt_opts, 0, oldsb, newsb, - kern_flags, set_kern_flags); + return call_int_hook(sb_clone_mnt_opts, oldsb, newsb, + kern_flags, set_kern_flags); } EXPORT_SYMBOL(security_sb_clone_mnt_opts); -int security_move_mount(const struct path *from_path, const struct path *to_path) +/** + * security_move_mount() - Check permissions for moving a mount + * @from_path: source mount point + * @to_path: destination mount point + * + * Check permission before a mount is moved. + * + * Return: Returns 0 if permission is granted. + */ +int security_move_mount(const struct path *from_path, + const struct path *to_path) { - return call_int_hook(move_mount, 0, from_path, to_path); + return call_int_hook(move_mount, from_path, to_path); } +/** + * security_path_notify() - Check if setting a watch is allowed + * @path: file path + * @mask: event mask + * @obj_type: file path type + * + * Check permissions before setting a watch on events as defined by @mask, on + * an object at @path, whose type is defined by @obj_type. + * + * Return: Returns 0 if permission is granted. + */ int security_path_notify(const struct path *path, u64 mask, - unsigned int obj_type) + unsigned int obj_type) { - return call_int_hook(path_notify, 0, path, mask, obj_type); + return call_int_hook(path_notify, path, mask, obj_type); } -int security_inode_alloc(struct inode *inode) +/** + * security_inode_alloc() - Allocate an inode LSM blob + * @inode: the inode + * @gfp: allocation flags + * + * Allocate and attach a security structure to @inode->i_security. The + * i_security field is initialized to NULL when the inode structure is + * allocated. + * + * Return: Return 0 if operation was successful. + */ +int security_inode_alloc(struct inode *inode, gfp_t gfp) { - int rc = lsm_inode_alloc(inode); + int rc = lsm_inode_alloc(inode, gfp); if (unlikely(rc)) return rc; - rc = call_int_hook(inode_alloc_security, 0, inode); + rc = call_int_hook(inode_alloc_security, inode); if (unlikely(rc)) security_inode_free(inode); return rc; @@ -1063,549 +1198,1212 @@ int security_inode_alloc(struct inode *inode) static void inode_free_by_rcu(struct rcu_head *head) { - /* - * The rcu head is at the start of the inode blob - */ + /* The rcu head is at the start of the inode blob */ + call_void_hook(inode_free_security_rcu, head); kmem_cache_free(lsm_inode_cache, head); } +/** + * security_inode_free() - Free an inode's LSM blob + * @inode: the inode + * + * Release any LSM resources associated with @inode, although due to the + * inode's RCU protections it is possible that the resources will not be + * fully released until after the current RCU grace period has elapsed. + * + * It is important for LSMs to note that despite being present in a call to + * security_inode_free(), @inode may still be referenced in a VFS path walk + * and calls to security_inode_permission() may be made during, or after, + * a call to security_inode_free(). For this reason the inode->i_security + * field is released via a call_rcu() callback and any LSMs which need to + * retain inode state for use in security_inode_permission() should only + * release that state in the inode_free_security_rcu() LSM hook callback. + */ void security_inode_free(struct inode *inode) { - integrity_inode_free(inode); call_void_hook(inode_free_security, inode); - /* - * The inode may still be referenced in a path walk and - * a call to security_inode_permission() can be made - * after inode_free_security() is called. Ideally, the VFS - * wouldn't do this, but fixing that is a much harder - * job. For now, simply free the i_security via RCU, and - * leave the current inode->i_security pointer intact. - * The inode will be freed after the RCU grace period too. - */ - if (inode->i_security) - call_rcu((struct rcu_head *)inode->i_security, - inode_free_by_rcu); + if (!inode->i_security) + return; + call_rcu((struct rcu_head *)inode->i_security, inode_free_by_rcu); } +/** + * security_dentry_init_security() - Perform dentry initialization + * @dentry: the dentry to initialize + * @mode: mode used to determine resource type + * @name: name of the last path component + * @xattr_name: name of the security/LSM xattr + * @lsmctx: pointer to the resulting LSM context + * + * Compute a context for a dentry as the inode is not yet available since NFSv4 + * has no label backed by an EA anyway. It is important to note that + * @xattr_name does not need to be free'd by the caller, it is a static string. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_dentry_init_security(struct dentry *dentry, int mode, const struct qstr *name, - const char **xattr_name, void **ctx, - u32 *ctxlen) + const char **xattr_name, + struct lsm_context *lsmctx) { - struct security_hook_list *hp; - int rc; - - /* - * Only one module will provide a security context. - */ - hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security, list) { - rc = hp->hook.dentry_init_security(dentry, mode, name, - xattr_name, ctx, ctxlen); - if (rc != LSM_RET_DEFAULT(dentry_init_security)) - return rc; - } - return LSM_RET_DEFAULT(dentry_init_security); + return call_int_hook(dentry_init_security, dentry, mode, name, + xattr_name, lsmctx); } EXPORT_SYMBOL(security_dentry_init_security); +/** + * security_dentry_create_files_as() - Perform dentry initialization + * @dentry: the dentry to initialize + * @mode: mode used to determine resource type + * @name: name of the last path component + * @old: creds to use for LSM context calculations + * @new: creds to modify + * + * Compute a context for a dentry as the inode is not yet available and set + * that context in passed in creds so that new files are created using that + * context. Context is calculated using the passed in creds and not the creds + * of the caller. + * + * Return: Returns 0 on success, error on failure. + */ int security_dentry_create_files_as(struct dentry *dentry, int mode, - struct qstr *name, + const struct qstr *name, const struct cred *old, struct cred *new) { - return call_int_hook(dentry_create_files_as, 0, dentry, mode, - name, old, new); + return call_int_hook(dentry_create_files_as, dentry, mode, + name, old, new); } EXPORT_SYMBOL(security_dentry_create_files_as); +/** + * security_inode_init_security() - Initialize an inode's LSM context + * @inode: the inode + * @dir: parent directory + * @qstr: last component of the pathname + * @initxattrs: callback function to write xattrs + * @fs_data: filesystem specific data + * + * Obtain the security attribute name suffix and value to set on a newly + * created inode and set up the incore security field for the new inode. This + * hook is called by the fs code as part of the inode creation transaction and + * provides for atomic labeling of the inode, unlike the post_create/mkdir/... + * hooks called by the VFS. + * + * The hook function is expected to populate the xattrs array, by calling + * lsm_get_xattr_slot() to retrieve the slots reserved by the security module + * with the lbs_xattr_count field of the lsm_blob_sizes structure. For each + * slot, the hook function should set ->name to the attribute name suffix + * (e.g. selinux), to allocate ->value (will be freed by the caller) and set it + * to the attribute value, to set ->value_len to the length of the value. If + * the security module does not use security attributes or does not wish to put + * a security attribute on this particular inode, then it should return + * -EOPNOTSUPP to skip this processing. + * + * Return: Returns 0 if the LSM successfully initialized all of the inode + * security attributes that are required, negative values otherwise. + */ int security_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, const initxattrs initxattrs, void *fs_data) { - struct xattr new_xattrs[MAX_LSM_EVM_XATTR + 1]; - struct xattr *lsm_xattr, *evm_xattr, *xattr; - int ret; + struct lsm_static_call *scall; + struct xattr *new_xattrs = NULL; + int ret = -EOPNOTSUPP, xattr_count = 0; if (unlikely(IS_PRIVATE(inode))) return 0; - if (!initxattrs) - return call_int_hook(inode_init_security, -EOPNOTSUPP, inode, - dir, qstr, NULL, NULL, NULL); - memset(new_xattrs, 0, sizeof(new_xattrs)); - lsm_xattr = new_xattrs; - ret = call_int_hook(inode_init_security, -EOPNOTSUPP, inode, dir, qstr, - &lsm_xattr->name, - &lsm_xattr->value, - &lsm_xattr->value_len); - if (ret) - goto out; + if (!blob_sizes.lbs_xattr_count) + return 0; + + if (initxattrs) { + /* Allocate +1 as terminator. */ + new_xattrs = kcalloc(blob_sizes.lbs_xattr_count + 1, + sizeof(*new_xattrs), GFP_NOFS); + if (!new_xattrs) + return -ENOMEM; + } - evm_xattr = lsm_xattr + 1; - ret = evm_inode_init_security(inode, lsm_xattr, evm_xattr); - if (ret) + lsm_for_each_hook(scall, inode_init_security) { + ret = scall->hl->hook.inode_init_security(inode, dir, qstr, new_xattrs, + &xattr_count); + if (ret && ret != -EOPNOTSUPP) + goto out; + /* + * As documented in lsm_hooks.h, -EOPNOTSUPP in this context + * means that the LSM is not willing to provide an xattr, not + * that it wants to signal an error. Thus, continue to invoke + * the remaining LSMs. + */ + } + + /* If initxattrs() is NULL, xattr_count is zero, skip the call. */ + if (!xattr_count) goto out; + ret = initxattrs(inode, new_xattrs, fs_data); out: - for (xattr = new_xattrs; xattr->value != NULL; xattr++) - kfree(xattr->value); + for (; xattr_count > 0; xattr_count--) + kfree(new_xattrs[xattr_count - 1].value); + kfree(new_xattrs); return (ret == -EOPNOTSUPP) ? 0 : ret; } EXPORT_SYMBOL(security_inode_init_security); +/** + * security_inode_init_security_anon() - Initialize an anonymous inode + * @inode: the inode + * @name: the anonymous inode class + * @context_inode: an optional related inode + * + * Set up the incore security field for the new anonymous inode and return + * whether the inode creation is permitted by the security module or not. + * + * Return: Returns 0 on success, -EACCES if the security module denies the + * creation of this inode, or another -errno upon other errors. + */ int security_inode_init_security_anon(struct inode *inode, const struct qstr *name, const struct inode *context_inode) { - return call_int_hook(inode_init_security_anon, 0, inode, name, + return call_int_hook(inode_init_security_anon, inode, name, context_inode); } -int security_old_inode_init_security(struct inode *inode, struct inode *dir, - const struct qstr *qstr, const char **name, - void **value, size_t *len) -{ - if (unlikely(IS_PRIVATE(inode))) - return -EOPNOTSUPP; - return call_int_hook(inode_init_security, -EOPNOTSUPP, inode, dir, - qstr, name, value, len); -} -EXPORT_SYMBOL(security_old_inode_init_security); - #ifdef CONFIG_SECURITY_PATH -int security_path_mknod(const struct path *dir, struct dentry *dentry, umode_t mode, - unsigned int dev) +/** + * security_path_mknod() - Check if creating a special file is allowed + * @dir: parent directory + * @dentry: new file + * @mode: new file mode + * @dev: device number + * + * Check permissions when creating a file. Note that this hook is called even + * if mknod operation is being done for a regular file. + * + * Return: Returns 0 if permission is granted. + */ +int security_path_mknod(const struct path *dir, struct dentry *dentry, + umode_t mode, unsigned int dev) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) return 0; - return call_int_hook(path_mknod, 0, dir, dentry, mode, dev); + return call_int_hook(path_mknod, dir, dentry, mode, dev); } EXPORT_SYMBOL(security_path_mknod); -int security_path_mkdir(const struct path *dir, struct dentry *dentry, umode_t mode) +/** + * security_path_post_mknod() - Update inode security after reg file creation + * @idmap: idmap of the mount + * @dentry: new file + * + * Update inode security field after a regular file has been created. + */ +void security_path_post_mknod(struct mnt_idmap *idmap, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(path_post_mknod, idmap, dentry); +} + +/** + * security_path_mkdir() - Check if creating a new directory is allowed + * @dir: parent directory + * @dentry: new directory + * @mode: new directory mode + * + * Check permissions to create a new directory in the existing directory. + * + * Return: Returns 0 if permission is granted. + */ +int security_path_mkdir(const struct path *dir, struct dentry *dentry, + umode_t mode) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) return 0; - return call_int_hook(path_mkdir, 0, dir, dentry, mode); + return call_int_hook(path_mkdir, dir, dentry, mode); } EXPORT_SYMBOL(security_path_mkdir); +/** + * security_path_rmdir() - Check if removing a directory is allowed + * @dir: parent directory + * @dentry: directory to remove + * + * Check the permission to remove a directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_rmdir(const struct path *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) return 0; - return call_int_hook(path_rmdir, 0, dir, dentry); + return call_int_hook(path_rmdir, dir, dentry); } +/** + * security_path_unlink() - Check if removing a hard link is allowed + * @dir: parent directory + * @dentry: file + * + * Check the permission to remove a hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_path_unlink(const struct path *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) return 0; - return call_int_hook(path_unlink, 0, dir, dentry); + return call_int_hook(path_unlink, dir, dentry); } EXPORT_SYMBOL(security_path_unlink); +/** + * security_path_symlink() - Check if creating a symbolic link is allowed + * @dir: parent directory + * @dentry: symbolic link + * @old_name: file pathname + * + * Check the permission to create a symbolic link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_path_symlink(const struct path *dir, struct dentry *dentry, const char *old_name) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) return 0; - return call_int_hook(path_symlink, 0, dir, dentry, old_name); + return call_int_hook(path_symlink, dir, dentry, old_name); } +/** + * security_path_link - Check if creating a hard link is allowed + * @old_dentry: existing file + * @new_dir: new parent directory + * @new_dentry: new link + * + * Check permission before creating a new hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_path_link(struct dentry *old_dentry, const struct path *new_dir, struct dentry *new_dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)))) return 0; - return call_int_hook(path_link, 0, old_dentry, new_dir, new_dentry); + return call_int_hook(path_link, old_dentry, new_dir, new_dentry); } +/** + * security_path_rename() - Check if renaming a file is allowed + * @old_dir: parent directory of the old file + * @old_dentry: the old file + * @new_dir: parent directory of the new file + * @new_dentry: the new file + * @flags: flags + * + * Check for permission to rename a file or directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_rename(const struct path *old_dir, struct dentry *old_dentry, const struct path *new_dir, struct dentry *new_dentry, unsigned int flags) { if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || - (d_is_positive(new_dentry) && IS_PRIVATE(d_backing_inode(new_dentry))))) + (d_is_positive(new_dentry) && + IS_PRIVATE(d_backing_inode(new_dentry))))) return 0; - return call_int_hook(path_rename, 0, old_dir, old_dentry, new_dir, - new_dentry, flags); + return call_int_hook(path_rename, old_dir, old_dentry, new_dir, + new_dentry, flags); } EXPORT_SYMBOL(security_path_rename); +/** + * security_path_truncate() - Check if truncating a file is allowed + * @path: file + * + * Check permission before truncating the file indicated by path. Note that + * truncation permissions may also be checked based on already opened files, + * using the security_file_truncate() hook. + * + * Return: Returns 0 if permission is granted. + */ int security_path_truncate(const struct path *path) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) return 0; - return call_int_hook(path_truncate, 0, path); + return call_int_hook(path_truncate, path); } +/** + * security_path_chmod() - Check if changing the file's mode is allowed + * @path: file + * @mode: new mode + * + * Check for permission to change a mode of the file @path. The new mode is + * specified in @mode which is a bitmask of constants from + * <include/uapi/linux/stat.h>. + * + * Return: Returns 0 if permission is granted. + */ int security_path_chmod(const struct path *path, umode_t mode) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) return 0; - return call_int_hook(path_chmod, 0, path, mode); + return call_int_hook(path_chmod, path, mode); } +/** + * security_path_chown() - Check if changing the file's owner/group is allowed + * @path: file + * @uid: file owner + * @gid: file group + * + * Check for permission to change owner/group of a file or directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_chown(const struct path *path, kuid_t uid, kgid_t gid) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) return 0; - return call_int_hook(path_chown, 0, path, uid, gid); + return call_int_hook(path_chown, path, uid, gid); } +/** + * security_path_chroot() - Check if changing the root directory is allowed + * @path: directory + * + * Check for permission to change root directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_chroot(const struct path *path) { - return call_int_hook(path_chroot, 0, path); + return call_int_hook(path_chroot, path); } -#endif +#endif /* CONFIG_SECURITY_PATH */ -int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) +/** + * security_inode_create() - Check if creating a file is allowed + * @dir: the parent directory + * @dentry: the file being created + * @mode: requested file mode + * + * Check permission to create a regular file. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_create(struct inode *dir, struct dentry *dentry, + umode_t mode) { if (unlikely(IS_PRIVATE(dir))) return 0; - return call_int_hook(inode_create, 0, dir, dentry, mode); + return call_int_hook(inode_create, dir, dentry, mode); } EXPORT_SYMBOL_GPL(security_inode_create); +/** + * security_inode_post_create_tmpfile() - Update inode security of new tmpfile + * @idmap: idmap of the mount + * @inode: inode of the new tmpfile + * + * Update inode security data after a tmpfile has been created. + */ +void security_inode_post_create_tmpfile(struct mnt_idmap *idmap, + struct inode *inode) +{ + if (unlikely(IS_PRIVATE(inode))) + return; + call_void_hook(inode_post_create_tmpfile, idmap, inode); +} + +/** + * security_inode_link() - Check if creating a hard link is allowed + * @old_dentry: existing file + * @dir: new parent directory + * @new_dentry: new link + * + * Check permission before creating a new hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_link(struct dentry *old_dentry, struct inode *dir, - struct dentry *new_dentry) + struct dentry *new_dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)))) return 0; - return call_int_hook(inode_link, 0, old_dentry, dir, new_dentry); + return call_int_hook(inode_link, old_dentry, dir, new_dentry); } +/** + * security_inode_unlink() - Check if removing a hard link is allowed + * @dir: parent directory + * @dentry: file + * + * Check the permission to remove a hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_unlink(struct inode *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - return call_int_hook(inode_unlink, 0, dir, dentry); + return call_int_hook(inode_unlink, dir, dentry); } +/** + * security_inode_symlink() - Check if creating a symbolic link is allowed + * @dir: parent directory + * @dentry: symbolic link + * @old_name: existing filename + * + * Check the permission to create a symbolic link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_symlink(struct inode *dir, struct dentry *dentry, - const char *old_name) + const char *old_name) { if (unlikely(IS_PRIVATE(dir))) return 0; - return call_int_hook(inode_symlink, 0, dir, dentry, old_name); + return call_int_hook(inode_symlink, dir, dentry, old_name); } +/** + * security_inode_mkdir() - Check if creating a new directory is allowed + * @dir: parent directory + * @dentry: new directory + * @mode: new directory mode + * + * Check permissions to create a new directory in the existing directory + * associated with inode structure @dir. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { if (unlikely(IS_PRIVATE(dir))) return 0; - return call_int_hook(inode_mkdir, 0, dir, dentry, mode); + return call_int_hook(inode_mkdir, dir, dentry, mode); } EXPORT_SYMBOL_GPL(security_inode_mkdir); +/** + * security_inode_rmdir() - Check if removing a directory is allowed + * @dir: parent directory + * @dentry: directory to be removed + * + * Check the permission to remove a directory. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_rmdir(struct inode *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - return call_int_hook(inode_rmdir, 0, dir, dentry); + return call_int_hook(inode_rmdir, dir, dentry); } -int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +/** + * security_inode_mknod() - Check if creating a special file is allowed + * @dir: parent directory + * @dentry: new file + * @mode: new file mode + * @dev: device number + * + * Check permissions when creating a special file (or a socket or a fifo file + * created via the mknod system call). Note that if mknod operation is being + * done for a regular file, then the create hook will be called and not this + * hook. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_mknod(struct inode *dir, struct dentry *dentry, + umode_t mode, dev_t dev) { if (unlikely(IS_PRIVATE(dir))) return 0; - return call_int_hook(inode_mknod, 0, dir, dentry, mode, dev); + return call_int_hook(inode_mknod, dir, dentry, mode, dev); } +/** + * security_inode_rename() - Check if renaming a file is allowed + * @old_dir: parent directory of the old file + * @old_dentry: the old file + * @new_dir: parent directory of the new file + * @new_dentry: the new file + * @flags: flags + * + * Check for permission to rename a file or directory. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - unsigned int flags) + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) { - if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || - (d_is_positive(new_dentry) && IS_PRIVATE(d_backing_inode(new_dentry))))) + if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || + (d_is_positive(new_dentry) && + IS_PRIVATE(d_backing_inode(new_dentry))))) return 0; if (flags & RENAME_EXCHANGE) { - int err = call_int_hook(inode_rename, 0, new_dir, new_dentry, - old_dir, old_dentry); + int err = call_int_hook(inode_rename, new_dir, new_dentry, + old_dir, old_dentry); if (err) return err; } - return call_int_hook(inode_rename, 0, old_dir, old_dentry, - new_dir, new_dentry); + return call_int_hook(inode_rename, old_dir, old_dentry, + new_dir, new_dentry); } +/** + * security_inode_readlink() - Check if reading a symbolic link is allowed + * @dentry: link + * + * Check the permission to read the symbolic link. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_readlink(struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - return call_int_hook(inode_readlink, 0, dentry); + return call_int_hook(inode_readlink, dentry); } +/** + * security_inode_follow_link() - Check if following a symbolic link is allowed + * @dentry: link dentry + * @inode: link inode + * @rcu: true if in RCU-walk mode + * + * Check permission to follow a symbolic link when looking up a pathname. If + * @rcu is true, @inode is not stable. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_follow_link(struct dentry *dentry, struct inode *inode, bool rcu) { if (unlikely(IS_PRIVATE(inode))) return 0; - return call_int_hook(inode_follow_link, 0, dentry, inode, rcu); + return call_int_hook(inode_follow_link, dentry, inode, rcu); } +/** + * security_inode_permission() - Check if accessing an inode is allowed + * @inode: inode + * @mask: access mask + * + * Check permission before accessing an inode. This hook is called by the + * existing Linux permission function, so a security module can use it to + * provide additional checking for existing Linux permission checks. Notice + * that this hook is called when a file is opened (as well as many other + * operations), whereas the file_security_ops permission hook is called when + * the actual read/write operations are performed. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_permission(struct inode *inode, int mask) { if (unlikely(IS_PRIVATE(inode))) return 0; - return call_int_hook(inode_permission, 0, inode, mask); + return call_int_hook(inode_permission, inode, mask); } -int security_inode_setattr(struct user_namespace *mnt_userns, +/** + * security_inode_setattr() - Check if setting file attributes is allowed + * @idmap: idmap of the mount + * @dentry: file + * @attr: new attributes + * + * Check permission before setting file attributes. Note that the kernel call + * to notify_change is performed from several locations, whenever file + * attributes change (such as when a file is truncated, chown/chmod operations, + * transferring disk quotas, etc). + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr) { - int ret; - if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - ret = call_int_hook(inode_setattr, 0, dentry, attr); - if (ret) - return ret; - return evm_inode_setattr(mnt_userns, dentry, attr); + return call_int_hook(inode_setattr, idmap, dentry, attr); } EXPORT_SYMBOL_GPL(security_inode_setattr); +/** + * security_inode_post_setattr() - Update the inode after a setattr operation + * @idmap: idmap of the mount + * @dentry: file + * @ia_valid: file attributes set + * + * Update inode security field after successful setting file attributes. + */ +void security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + int ia_valid) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_setattr, idmap, dentry, ia_valid); +} + +/** + * security_inode_getattr() - Check if getting file attributes is allowed + * @path: file + * + * Check permission before obtaining file attributes. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_getattr(const struct path *path) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) return 0; - return call_int_hook(inode_getattr, 0, path); + return call_int_hook(inode_getattr, path); } -int security_inode_setxattr(struct user_namespace *mnt_userns, +/** + * security_inode_setxattr() - Check if setting file xattrs is allowed + * @idmap: idmap of the mount + * @dentry: file + * @name: xattr name + * @value: xattr value + * @size: size of xattr value + * @flags: flags + * + * This hook performs the desired permission checks before setting the extended + * attributes (xattrs) on @dentry. It is important to note that we have some + * additional logic before the main LSM implementation calls to detect if we + * need to perform an additional capability check at the LSM layer. + * + * Normally we enforce a capability check prior to executing the various LSM + * hook implementations, but if a LSM wants to avoid this capability check, + * it can register a 'inode_xattr_skipcap' hook and return a value of 1 for + * xattrs that it wants to avoid the capability check, leaving the LSM fully + * responsible for enforcing the access control for the specific xattr. If all + * of the enabled LSMs refrain from registering a 'inode_xattr_skipcap' hook, + * or return a 0 (the default return value), the capability check is still + * performed. If no 'inode_xattr_skipcap' hooks are registered the capability + * check is performed. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { - int ret; + int rc; if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - /* - * SELinux and Smack integrate the cap call, - * so assume that all LSMs supplying this call do so. - */ - ret = call_int_hook(inode_setxattr, 1, mnt_userns, dentry, name, value, - size, flags); - if (ret == 1) - ret = cap_inode_setxattr(dentry, name, value, size, flags); - if (ret) - return ret; - ret = ima_inode_setxattr(dentry, name, value, size); - if (ret) - return ret; - return evm_inode_setxattr(mnt_userns, dentry, name, value, size); + /* enforce the capability checks at the lsm layer, if needed */ + if (!call_int_hook(inode_xattr_skipcap, name)) { + rc = cap_inode_setxattr(dentry, name, value, size, flags); + if (rc) + return rc; + } + + return call_int_hook(inode_setxattr, idmap, dentry, name, value, size, + flags); } -int security_inode_set_acl(struct user_namespace *mnt_userns, +/** + * security_inode_set_acl() - Check if setting posix acls is allowed + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * @kacl: acl struct + * + * Check permission before setting posix acls, the posix acls in @kacl are + * identified by @acl_name. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl) { - int ret; - if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - ret = call_int_hook(inode_set_acl, 0, mnt_userns, dentry, acl_name, - kacl); - if (ret) - return ret; - ret = ima_inode_set_acl(mnt_userns, dentry, acl_name, kacl); - if (ret) - return ret; - return evm_inode_set_acl(mnt_userns, dentry, acl_name, kacl); + return call_int_hook(inode_set_acl, idmap, dentry, acl_name, kacl); } -int security_inode_get_acl(struct user_namespace *mnt_userns, +/** + * security_inode_post_set_acl() - Update inode security from posix acls set + * @dentry: file + * @acl_name: acl name + * @kacl: acl struct + * + * Update inode security data after successfully setting posix acls on @dentry. + * The posix acls in @kacl are identified by @acl_name. + */ +void security_inode_post_set_acl(struct dentry *dentry, const char *acl_name, + struct posix_acl *kacl) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_set_acl, dentry, acl_name, kacl); +} + +/** + * security_inode_get_acl() - Check if reading posix acls is allowed + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * + * Check permission before getting osix acls, the posix acls are identified by + * @acl_name. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - return call_int_hook(inode_get_acl, 0, mnt_userns, dentry, acl_name); + return call_int_hook(inode_get_acl, idmap, dentry, acl_name); } -int security_inode_remove_acl(struct user_namespace *mnt_userns, +/** + * security_inode_remove_acl() - Check if removing a posix acl is allowed + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * + * Check permission before removing posix acls, the posix acls are identified + * by @acl_name. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) { - int ret; - if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - ret = call_int_hook(inode_remove_acl, 0, mnt_userns, dentry, acl_name); - if (ret) - return ret; - ret = ima_inode_remove_acl(mnt_userns, dentry, acl_name); - if (ret) - return ret; - return evm_inode_remove_acl(mnt_userns, dentry, acl_name); + return call_int_hook(inode_remove_acl, idmap, dentry, acl_name); +} + +/** + * security_inode_post_remove_acl() - Update inode security after rm posix acls + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * + * Update inode security data after successfully removing posix acls on + * @dentry in @idmap. The posix acls are identified by @acl_name. + */ +void security_inode_post_remove_acl(struct mnt_idmap *idmap, + struct dentry *dentry, const char *acl_name) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_remove_acl, idmap, dentry, acl_name); } +/** + * security_inode_post_setxattr() - Update the inode after a setxattr operation + * @dentry: file + * @name: xattr name + * @value: xattr value + * @size: xattr value size + * @flags: flags + * + * Update inode security field after successful setxattr operation. + */ void security_inode_post_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return; call_void_hook(inode_post_setxattr, dentry, name, value, size, flags); - evm_inode_post_setxattr(dentry, name, value, size); } +/** + * security_inode_getxattr() - Check if xattr access is allowed + * @dentry: file + * @name: xattr name + * + * Check permission before obtaining the extended attributes identified by + * @name for @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_getxattr(struct dentry *dentry, const char *name) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - return call_int_hook(inode_getxattr, 0, dentry, name); + return call_int_hook(inode_getxattr, dentry, name); } +/** + * security_inode_listxattr() - Check if listing xattrs is allowed + * @dentry: file + * + * Check permission before obtaining the list of extended attribute names for + * @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_listxattr(struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - return call_int_hook(inode_listxattr, 0, dentry); + return call_int_hook(inode_listxattr, dentry); } -int security_inode_removexattr(struct user_namespace *mnt_userns, +/** + * security_inode_removexattr() - Check if removing an xattr is allowed + * @idmap: idmap of the mount + * @dentry: file + * @name: xattr name + * + * This hook performs the desired permission checks before setting the extended + * attributes (xattrs) on @dentry. It is important to note that we have some + * additional logic before the main LSM implementation calls to detect if we + * need to perform an additional capability check at the LSM layer. + * + * Normally we enforce a capability check prior to executing the various LSM + * hook implementations, but if a LSM wants to avoid this capability check, + * it can register a 'inode_xattr_skipcap' hook and return a value of 1 for + * xattrs that it wants to avoid the capability check, leaving the LSM fully + * responsible for enforcing the access control for the specific xattr. If all + * of the enabled LSMs refrain from registering a 'inode_xattr_skipcap' hook, + * or return a 0 (the default return value), the capability check is still + * performed. If no 'inode_xattr_skipcap' hooks are registered the capability + * check is performed. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_removexattr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name) { - int ret; + int rc; if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - /* - * SELinux and Smack integrate the cap call, - * so assume that all LSMs supplying this call do so. - */ - ret = call_int_hook(inode_removexattr, 1, mnt_userns, dentry, name); - if (ret == 1) - ret = cap_inode_removexattr(mnt_userns, dentry, name); - if (ret) - return ret; - ret = ima_inode_removexattr(dentry, name); - if (ret) - return ret; - return evm_inode_removexattr(mnt_userns, dentry, name); + + /* enforce the capability checks at the lsm layer, if needed */ + if (!call_int_hook(inode_xattr_skipcap, name)) { + rc = cap_inode_removexattr(idmap, dentry, name); + if (rc) + return rc; + } + + return call_int_hook(inode_removexattr, idmap, dentry, name); +} + +/** + * security_inode_post_removexattr() - Update the inode after a removexattr op + * @dentry: file + * @name: xattr name + * + * Update the inode after a successful removexattr operation. + */ +void security_inode_post_removexattr(struct dentry *dentry, const char *name) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_removexattr, dentry, name); +} + +/** + * security_inode_file_setattr() - check if setting fsxattr is allowed + * @dentry: file to set filesystem extended attributes on + * @fa: extended attributes to set on the inode + * + * Called when file_setattr() syscall or FS_IOC_FSSETXATTR ioctl() is called on + * inode + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_file_setattr(struct dentry *dentry, struct file_kattr *fa) +{ + return call_int_hook(inode_file_setattr, dentry, fa); } +/** + * security_inode_file_getattr() - check if retrieving fsxattr is allowed + * @dentry: file to retrieve filesystem extended attributes from + * @fa: extended attributes to get + * + * Called when file_getattr() syscall or FS_IOC_FSGETXATTR ioctl() is called on + * inode + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_file_getattr(struct dentry *dentry, struct file_kattr *fa) +{ + return call_int_hook(inode_file_getattr, dentry, fa); +} + +/** + * security_inode_need_killpriv() - Check if security_inode_killpriv() required + * @dentry: associated dentry + * + * Called when an inode has been changed to determine if + * security_inode_killpriv() should be called. + * + * Return: Return <0 on error to abort the inode change operation, return 0 if + * security_inode_killpriv() does not need to be called, return >0 if + * security_inode_killpriv() does need to be called. + */ int security_inode_need_killpriv(struct dentry *dentry) { - return call_int_hook(inode_need_killpriv, 0, dentry); + return call_int_hook(inode_need_killpriv, dentry); } -int security_inode_killpriv(struct user_namespace *mnt_userns, +/** + * security_inode_killpriv() - The setuid bit is removed, update LSM state + * @idmap: idmap of the mount + * @dentry: associated dentry + * + * The @dentry's setuid bit is being removed. Remove similar security labels. + * Called with the dentry->d_inode->i_mutex held. + * + * Return: Return 0 on success. If error is returned, then the operation + * causing setuid bit removal is failed. + */ +int security_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry) { - return call_int_hook(inode_killpriv, 0, mnt_userns, dentry); + return call_int_hook(inode_killpriv, idmap, dentry); } -int security_inode_getsecurity(struct user_namespace *mnt_userns, +/** + * security_inode_getsecurity() - Get the xattr security label of an inode + * @idmap: idmap of the mount + * @inode: inode + * @name: xattr name + * @buffer: security label buffer + * @alloc: allocation flag + * + * Retrieve a copy of the extended attribute representation of the security + * label associated with @name for @inode via @buffer. Note that @name is the + * remainder of the attribute name after the security prefix has been removed. + * @alloc is used to specify if the call should return a value via the buffer + * or just the value length. + * + * Return: Returns size of buffer on success. + */ +int security_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, void **buffer, bool alloc) { - struct security_hook_list *hp; - int rc; - if (unlikely(IS_PRIVATE(inode))) return LSM_RET_DEFAULT(inode_getsecurity); - /* - * Only one module will provide an attribute with a given name. - */ - hlist_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) { - rc = hp->hook.inode_getsecurity(mnt_userns, inode, name, buffer, alloc); - if (rc != LSM_RET_DEFAULT(inode_getsecurity)) - return rc; - } - return LSM_RET_DEFAULT(inode_getsecurity); + + return call_int_hook(inode_getsecurity, idmap, inode, name, buffer, + alloc); } -int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) +/** + * security_inode_setsecurity() - Set the xattr security label of an inode + * @inode: inode + * @name: xattr name + * @value: security label + * @size: length of security label + * @flags: flags + * + * Set the security label associated with @name for @inode from the extended + * attribute value @value. @size indicates the size of the @value in bytes. + * @flags may be XATTR_CREATE, XATTR_REPLACE, or 0. Note that @name is the + * remainder of the attribute name after the security. prefix has been removed. + * + * Return: Returns 0 on success. + */ +int security_inode_setsecurity(struct inode *inode, const char *name, + const void *value, size_t size, int flags) { - struct security_hook_list *hp; - int rc; - if (unlikely(IS_PRIVATE(inode))) return LSM_RET_DEFAULT(inode_setsecurity); - /* - * Only one module will provide an attribute with a given name. - */ - hlist_for_each_entry(hp, &security_hook_heads.inode_setsecurity, list) { - rc = hp->hook.inode_setsecurity(inode, name, value, size, - flags); - if (rc != LSM_RET_DEFAULT(inode_setsecurity)) - return rc; - } - return LSM_RET_DEFAULT(inode_setsecurity); + + return call_int_hook(inode_setsecurity, inode, name, value, size, + flags); } -int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) +/** + * security_inode_listsecurity() - List the xattr security label names + * @inode: inode + * @buffer: buffer + * @buffer_size: size of buffer + * + * Copy the extended attribute names for the security labels associated with + * @inode into @buffer. The maximum size of @buffer is specified by + * @buffer_size. @buffer may be NULL to request the size of the buffer + * required. + * + * Return: Returns number of bytes used/required on success. + */ +int security_inode_listsecurity(struct inode *inode, + char *buffer, size_t buffer_size) { if (unlikely(IS_PRIVATE(inode))) return 0; - return call_int_hook(inode_listsecurity, 0, inode, buffer, buffer_size); + return call_int_hook(inode_listsecurity, inode, buffer, buffer_size); } EXPORT_SYMBOL(security_inode_listsecurity); -void security_inode_getsecid(struct inode *inode, u32 *secid) +/** + * security_inode_getlsmprop() - Get an inode's LSM data + * @inode: inode + * @prop: lsm specific information to return + * + * Get the lsm specific information associated with the node. + */ +void security_inode_getlsmprop(struct inode *inode, struct lsm_prop *prop) { - call_void_hook(inode_getsecid, inode, secid); + call_void_hook(inode_getlsmprop, inode, prop); } +/** + * security_inode_copy_up() - Create new creds for an overlayfs copy-up op + * @src: union dentry of copy-up file + * @new: newly created creds + * + * A file is about to be copied up from lower layer to upper layer of overlay + * filesystem. Security module can prepare a set of new creds and modify as + * need be and return new creds. Caller will switch to new creds temporarily to + * create new file and release newly allocated creds. + * + * Return: Returns 0 on success or a negative error code on error. + */ int security_inode_copy_up(struct dentry *src, struct cred **new) { - return call_int_hook(inode_copy_up, 0, src, new); + return call_int_hook(inode_copy_up, src, new); } EXPORT_SYMBOL(security_inode_copy_up); -int security_inode_copy_up_xattr(const char *name) +/** + * security_inode_copy_up_xattr() - Filter xattrs in an overlayfs copy-up op + * @src: union dentry of copy-up file + * @name: xattr name + * + * Filter the xattrs being copied up when a unioned file is copied up from a + * lower layer to the union/overlay layer. The caller is responsible for + * reading and writing the xattrs, this hook is merely a filter. + * + * Return: Returns 0 to accept the xattr, -ECANCELED to discard the xattr, + * -EOPNOTSUPP if the security module does not know about attribute, + * or a negative error code to abort the copy up. + */ +int security_inode_copy_up_xattr(struct dentry *src, const char *name) { - struct security_hook_list *hp; int rc; - /* - * The implementation can return 0 (accept the xattr), 1 (discard the - * xattr), -EOPNOTSUPP if it does not know anything about the xattr or - * any other error code incase of an error. - */ - hlist_for_each_entry(hp, - &security_hook_heads.inode_copy_up_xattr, list) { - rc = hp->hook.inode_copy_up_xattr(name); - if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) - return rc; - } + rc = call_int_hook(inode_copy_up_xattr, src, name); + if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) + return rc; return LSM_RET_DEFAULT(inode_copy_up_xattr); } EXPORT_SYMBOL(security_inode_copy_up_xattr); +/** + * security_inode_setintegrity() - Set the inode's integrity data + * @inode: inode + * @type: type of integrity, e.g. hash digest, signature, etc + * @value: the integrity value + * @size: size of the integrity value + * + * Register a verified integrity measurement of a inode with LSMs. + * LSMs should free the previously saved data if @value is NULL. + * + * Return: Returns 0 on success, negative values on failure. + */ +int security_inode_setintegrity(const struct inode *inode, + enum lsm_integrity_type type, const void *value, + size_t size) +{ + return call_int_hook(inode_setintegrity, inode, type, value, size); +} +EXPORT_SYMBOL(security_inode_setintegrity); + +/** + * security_kernfs_init_security() - Init LSM context for a kernfs node + * @kn_dir: parent kernfs node + * @kn: the kernfs node to initialize + * + * Initialize the security context of a newly created kernfs node based on its + * own and its parent's attributes. + * + * Return: Returns 0 if permission is granted. + */ int security_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn) { - return call_int_hook(kernfs_init_security, 0, kn_dir, kn); + return call_int_hook(kernfs_init_security, kn_dir, kn); } +/** + * security_file_permission() - Check file permissions + * @file: file + * @mask: requested permissions + * + * Check file permissions before accessing an open file. This hook is called + * by various operations that read or write files. A security module can use + * this hook to perform additional checking on these operations, e.g. to + * revalidate permissions on use to support privilege bracketing or policy + * changes. Notice that this hook is used when the actual read/write + * operations are performed, whereas the inode_security_ops hook is called when + * a file is opened (as well as many other operations). Although this hook can + * be used to revalidate permissions for various system call operations that + * read or write files, it does not address the revalidation of permissions for + * memory-mapped files. Security modules must handle this separately if they + * need such revalidation. + * + * Return: Returns 0 if permission is granted. + */ int security_file_permission(struct file *file, int mask) { - int ret; - - ret = call_int_hook(file_permission, 0, file, mask); - if (ret) - return ret; - - return fsnotify_perm(file, mask); + return call_int_hook(file_permission, file, mask); } +/** + * security_file_alloc() - Allocate and init a file's LSM blob + * @file: the file + * + * Allocate and attach a security structure to the file->f_security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Return 0 if the hook is successful and permission is granted. + */ int security_file_alloc(struct file *file) { int rc = lsm_file_alloc(file); if (rc) return rc; - rc = call_int_hook(file_alloc_security, 0, file); + rc = call_int_hook(file_alloc_security, file); if (unlikely(rc)) security_file_free(file); return rc; } +/** + * security_file_release() - Perform actions before releasing the file ref + * @file: the file + * + * Perform actions before releasing the last reference to a file. + */ +void security_file_release(struct file *file) +{ + call_void_hook(file_release, file); +} + +/** + * security_file_free() - Free a file's LSM blob + * @file: the file + * + * Deallocate and free any security structures stored in file->f_security. + */ void security_file_free(struct file *file) { void *blob; @@ -1619,12 +2417,43 @@ void security_file_free(struct file *file) } } +/** + * security_file_ioctl() - Check if an ioctl is allowed + * @file: associated file + * @cmd: ioctl cmd + * @arg: ioctl arguments + * + * Check permission for an ioctl operation on @file. Note that @arg sometimes + * represents a user space pointer; in other cases, it may be a simple integer + * value. When @arg represents a user space pointer, it should never be used + * by the security module. + * + * Return: Returns 0 if permission is granted. + */ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - return call_int_hook(file_ioctl, 0, file, cmd, arg); + return call_int_hook(file_ioctl, file, cmd, arg); } EXPORT_SYMBOL_GPL(security_file_ioctl); +/** + * security_file_ioctl_compat() - Check if an ioctl is allowed in compat mode + * @file: associated file + * @cmd: ioctl cmd + * @arg: ioctl arguments + * + * Compat version of security_file_ioctl() that correctly handles 32-bit + * processes running on 64-bit kernels. + * + * Return: Returns 0 if permission is granted. + */ +int security_file_ioctl_compat(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return call_int_hook(file_ioctl_compat, file, cmd, arg); +} +EXPORT_SYMBOL_GPL(security_file_ioctl_compat); + static inline unsigned long mmap_prot(struct file *file, unsigned long prot) { /* @@ -1658,87 +2487,215 @@ static inline unsigned long mmap_prot(struct file *file, unsigned long prot) return prot; } +/** + * security_mmap_file() - Check if mmap'ing a file is allowed + * @file: file + * @prot: protection applied by the kernel + * @flags: flags + * + * Check permissions for a mmap operation. The @file may be NULL, e.g. if + * mapping anonymous memory. + * + * Return: Returns 0 if permission is granted. + */ int security_mmap_file(struct file *file, unsigned long prot, - unsigned long flags) + unsigned long flags) { - int ret; - ret = call_int_hook(mmap_file, 0, file, prot, - mmap_prot(file, prot), flags); - if (ret) - return ret; - return ima_file_mmap(file, prot); + return call_int_hook(mmap_file, file, prot, mmap_prot(file, prot), + flags); } +/** + * security_mmap_addr() - Check if mmap'ing an address is allowed + * @addr: address + * + * Check permissions for a mmap operation at @addr. + * + * Return: Returns 0 if permission is granted. + */ int security_mmap_addr(unsigned long addr) { - return call_int_hook(mmap_addr, 0, addr); + return call_int_hook(mmap_addr, addr); } +/** + * security_file_mprotect() - Check if changing memory protections is allowed + * @vma: memory region + * @reqprot: application requested protection + * @prot: protection applied by the kernel + * + * Check permissions before changing memory access permissions. + * + * Return: Returns 0 if permission is granted. + */ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, - unsigned long prot) + unsigned long prot) { - int ret; - - ret = call_int_hook(file_mprotect, 0, vma, reqprot, prot); - if (ret) - return ret; - return ima_file_mprotect(vma, prot); + return call_int_hook(file_mprotect, vma, reqprot, prot); } +/** + * security_file_lock() - Check if a file lock is allowed + * @file: file + * @cmd: lock operation (e.g. F_RDLCK, F_WRLCK) + * + * Check permission before performing file locking operations. Note the hook + * mediates both flock and fcntl style locks. + * + * Return: Returns 0 if permission is granted. + */ int security_file_lock(struct file *file, unsigned int cmd) { - return call_int_hook(file_lock, 0, file, cmd); + return call_int_hook(file_lock, file, cmd); } +/** + * security_file_fcntl() - Check if fcntl() op is allowed + * @file: file + * @cmd: fcntl command + * @arg: command argument + * + * Check permission before allowing the file operation specified by @cmd from + * being performed on the file @file. Note that @arg sometimes represents a + * user space pointer; in other cases, it may be a simple integer value. When + * @arg represents a user space pointer, it should never be used by the + * security module. + * + * Return: Returns 0 if permission is granted. + */ int security_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg) { - return call_int_hook(file_fcntl, 0, file, cmd, arg); + return call_int_hook(file_fcntl, file, cmd, arg); } +/** + * security_file_set_fowner() - Set the file owner info in the LSM blob + * @file: the file + * + * Save owner security information (typically from current->security) in + * file->f_security for later use by the send_sigiotask hook. + * + * This hook is called with file->f_owner.lock held. + * + * Return: Returns 0 on success. + */ void security_file_set_fowner(struct file *file) { call_void_hook(file_set_fowner, file); } +/** + * security_file_send_sigiotask() - Check if sending SIGIO/SIGURG is allowed + * @tsk: target task + * @fown: signal sender + * @sig: signal to be sent, SIGIO is sent if 0 + * + * Check permission for the file owner @fown to send SIGIO or SIGURG to the + * process @tsk. Note that this hook is sometimes called from interrupt. Note + * that the fown_struct, @fown, is never outside the context of a struct file, + * so the file structure (and associated security information) can always be + * obtained: container_of(fown, struct file, f_owner). + * + * Return: Returns 0 if permission is granted. + */ int security_file_send_sigiotask(struct task_struct *tsk, - struct fown_struct *fown, int sig) + struct fown_struct *fown, int sig) { - return call_int_hook(file_send_sigiotask, 0, tsk, fown, sig); + return call_int_hook(file_send_sigiotask, tsk, fown, sig); } +/** + * security_file_receive() - Check if receiving a file via IPC is allowed + * @file: file being received + * + * This hook allows security modules to control the ability of a process to + * receive an open file descriptor via socket IPC. + * + * Return: Returns 0 if permission is granted. + */ int security_file_receive(struct file *file) { - return call_int_hook(file_receive, 0, file); + return call_int_hook(file_receive, file); } +/** + * security_file_open() - Save open() time state for late use by the LSM + * @file: + * + * Save open-time permission checking state for later use upon file_permission, + * and recheck access if anything has changed since inode_permission. + * + * We can check if a file is opened for execution (e.g. execve(2) call), either + * directly or indirectly (e.g. ELF's ld.so) by checking file->f_flags & + * __FMODE_EXEC . + * + * Return: Returns 0 if permission is granted. + */ int security_file_open(struct file *file) { - int ret; - - ret = call_int_hook(file_open, 0, file); - if (ret) - return ret; + return call_int_hook(file_open, file); +} - return fsnotify_perm(file, MAY_OPEN); +/** + * security_file_post_open() - Evaluate a file after it has been opened + * @file: the file + * @mask: access mask + * + * Evaluate an opened file and the access mask requested with open(). The hook + * is useful for LSMs that require the file content to be available in order to + * make decisions. + * + * Return: Returns 0 if permission is granted. + */ +int security_file_post_open(struct file *file, int mask) +{ + return call_int_hook(file_post_open, file, mask); } +EXPORT_SYMBOL_GPL(security_file_post_open); +/** + * security_file_truncate() - Check if truncating a file is allowed + * @file: file + * + * Check permission before truncating a file, i.e. using ftruncate. Note that + * truncation permission may also be checked based on the path, using the + * @path_truncate hook. + * + * Return: Returns 0 if permission is granted. + */ int security_file_truncate(struct file *file) { - return call_int_hook(file_truncate, 0, file); + return call_int_hook(file_truncate, file); } -int security_task_alloc(struct task_struct *task, unsigned long clone_flags) +/** + * security_task_alloc() - Allocate a task's LSM blob + * @task: the task + * @clone_flags: flags indicating what is being shared + * + * Handle allocation of task-related resources. + * + * Return: Returns a zero on success, negative values on failure. + */ +int security_task_alloc(struct task_struct *task, u64 clone_flags) { int rc = lsm_task_alloc(task); if (rc) return rc; - rc = call_int_hook(task_alloc, 0, task, clone_flags); + rc = call_int_hook(task_alloc, task, clone_flags); if (unlikely(rc)) security_task_free(task); return rc; } +/** + * security_task_free() - Free a task's LSM blob and related resources + * @task: task + * + * Handle release of task-related resources. Note that this can be called from + * interrupt context. + */ void security_task_free(struct task_struct *task) { call_void_hook(task_free, task); @@ -1747,6 +2704,16 @@ void security_task_free(struct task_struct *task) task->security = NULL; } +/** + * security_cred_alloc_blank() - Allocate the min memory to allow cred_transfer + * @cred: credentials + * @gfp: gfp flags + * + * Only allocate sufficient memory and attach to @cred such that + * cred_transfer() will not get ENOMEM. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) { int rc = lsm_cred_alloc(cred, gfp); @@ -1754,12 +2721,18 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) if (rc) return rc; - rc = call_int_hook(cred_alloc_blank, 0, cred, gfp); + rc = call_int_hook(cred_alloc_blank, cred, gfp); if (unlikely(rc)) security_cred_free(cred); return rc; } +/** + * security_cred_free() - Free the cred's LSM blob and associated resources + * @cred: credentials + * + * Deallocate and clear the cred->security field in a set of credentials. + */ void security_cred_free(struct cred *cred) { /* @@ -1775,6 +2748,16 @@ void security_cred_free(struct cred *cred) cred->security = NULL; } +/** + * security_prepare_creds() - Prepare a new set of credentials + * @new: new credentials + * @old: original credentials + * @gfp: gfp flags + * + * Prepare a new set of credentials by copying the data from the old set. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) { int rc = lsm_cred_alloc(new, gfp); @@ -1782,17 +2765,32 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) if (rc) return rc; - rc = call_int_hook(cred_prepare, 0, new, old, gfp); + rc = call_int_hook(cred_prepare, new, old, gfp); if (unlikely(rc)) security_cred_free(new); return rc; } +/** + * security_transfer_creds() - Transfer creds + * @new: target credentials + * @old: original credentials + * + * Transfer data from original creds to new creds. + */ void security_transfer_creds(struct cred *new, const struct cred *old) { call_void_hook(cred_transfer, new, old); } +/** + * security_cred_getsecid() - Get the secid from a set of credentials + * @c: credentials + * @secid: secid value + * + * Retrieve the security identifier of the cred structure @c. In case of + * failure, @secid will be set to zero. + */ void security_cred_getsecid(const struct cred *c, u32 *secid) { *secid = 0; @@ -1800,178 +2798,428 @@ void security_cred_getsecid(const struct cred *c, u32 *secid) } EXPORT_SYMBOL(security_cred_getsecid); +/** + * security_cred_getlsmprop() - Get the LSM data from a set of credentials + * @c: credentials + * @prop: destination for the LSM data + * + * Retrieve the security data of the cred structure @c. In case of + * failure, @prop will be cleared. + */ +void security_cred_getlsmprop(const struct cred *c, struct lsm_prop *prop) +{ + lsmprop_init(prop); + call_void_hook(cred_getlsmprop, c, prop); +} +EXPORT_SYMBOL(security_cred_getlsmprop); + +/** + * security_kernel_act_as() - Set the kernel credentials to act as secid + * @new: credentials + * @secid: secid + * + * Set the credentials for a kernel service to act as (subjective context). + * The current task must be the one that nominated @secid. + * + * Return: Returns 0 if successful. + */ int security_kernel_act_as(struct cred *new, u32 secid) { - return call_int_hook(kernel_act_as, 0, new, secid); + return call_int_hook(kernel_act_as, new, secid); } +/** + * security_kernel_create_files_as() - Set file creation context using an inode + * @new: target credentials + * @inode: reference inode + * + * Set the file creation context in a set of credentials to be the same as the + * objective context of the specified inode. The current task must be the one + * that nominated @inode. + * + * Return: Returns 0 if successful. + */ int security_kernel_create_files_as(struct cred *new, struct inode *inode) { - return call_int_hook(kernel_create_files_as, 0, new, inode); + return call_int_hook(kernel_create_files_as, new, inode); } +/** + * security_kernel_module_request() - Check if loading a module is allowed + * @kmod_name: module name + * + * Ability to trigger the kernel to automatically upcall to userspace for + * userspace to load a kernel module with the given name. + * + * Return: Returns 0 if successful. + */ int security_kernel_module_request(char *kmod_name) { - int ret; - - ret = call_int_hook(kernel_module_request, 0, kmod_name); - if (ret) - return ret; - return integrity_kernel_module_request(kmod_name); + return call_int_hook(kernel_module_request, kmod_name); } +/** + * security_kernel_read_file() - Read a file specified by userspace + * @file: file + * @id: file identifier + * @contents: trust if security_kernel_post_read_file() will be called + * + * Read a file specified by userspace. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_read_file(struct file *file, enum kernel_read_file_id id, bool contents) { - int ret; - - ret = call_int_hook(kernel_read_file, 0, file, id, contents); - if (ret) - return ret; - return ima_read_file(file, id, contents); + return call_int_hook(kernel_read_file, file, id, contents); } EXPORT_SYMBOL_GPL(security_kernel_read_file); +/** + * security_kernel_post_read_file() - Read a file specified by userspace + * @file: file + * @buf: file contents + * @size: size of file contents + * @id: file identifier + * + * Read a file specified by userspace. This must be paired with a prior call + * to security_kernel_read_file() call that indicated this hook would also be + * called, see security_kernel_read_file() for more information. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id) { - int ret; - - ret = call_int_hook(kernel_post_read_file, 0, file, buf, size, id); - if (ret) - return ret; - return ima_post_read_file(file, buf, size, id); + return call_int_hook(kernel_post_read_file, file, buf, size, id); } EXPORT_SYMBOL_GPL(security_kernel_post_read_file); +/** + * security_kernel_load_data() - Load data provided by userspace + * @id: data identifier + * @contents: true if security_kernel_post_load_data() will be called + * + * Load data provided by userspace. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_load_data(enum kernel_load_data_id id, bool contents) { - int ret; - - ret = call_int_hook(kernel_load_data, 0, id, contents); - if (ret) - return ret; - return ima_load_data(id, contents); + return call_int_hook(kernel_load_data, id, contents); } EXPORT_SYMBOL_GPL(security_kernel_load_data); +/** + * security_kernel_post_load_data() - Load userspace data from a non-file source + * @buf: data + * @size: size of data + * @id: data identifier + * @description: text description of data, specific to the id value + * + * Load data provided by a non-file source (usually userspace buffer). This + * must be paired with a prior security_kernel_load_data() call that indicated + * this hook would also be called, see security_kernel_load_data() for more + * information. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_post_load_data(char *buf, loff_t size, enum kernel_load_data_id id, char *description) { - int ret; - - ret = call_int_hook(kernel_post_load_data, 0, buf, size, id, - description); - if (ret) - return ret; - return ima_post_load_data(buf, size, id, description); + return call_int_hook(kernel_post_load_data, buf, size, id, description); } EXPORT_SYMBOL_GPL(security_kernel_post_load_data); +/** + * security_task_fix_setuid() - Update LSM with new user id attributes + * @new: updated credentials + * @old: credentials being replaced + * @flags: LSM_SETID_* flag values + * + * Update the module's state after setting one or more of the user identity + * attributes of the current process. The @flags parameter indicates which of + * the set*uid system calls invoked this hook. If @new is the set of + * credentials that will be installed. Modifications should be made to this + * rather than to @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { - return call_int_hook(task_fix_setuid, 0, new, old, flags); + return call_int_hook(task_fix_setuid, new, old, flags); } +/** + * security_task_fix_setgid() - Update LSM with new group id attributes + * @new: updated credentials + * @old: credentials being replaced + * @flags: LSM_SETID_* flag value + * + * Update the module's state after setting one or more of the group identity + * attributes of the current process. The @flags parameter indicates which of + * the set*gid system calls invoked this hook. @new is the set of credentials + * that will be installed. Modifications should be made to this rather than to + * @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setgid(struct cred *new, const struct cred *old, - int flags) + int flags) { - return call_int_hook(task_fix_setgid, 0, new, old, flags); + return call_int_hook(task_fix_setgid, new, old, flags); } +/** + * security_task_fix_setgroups() - Update LSM with new supplementary groups + * @new: updated credentials + * @old: credentials being replaced + * + * Update the module's state after setting the supplementary group identity + * attributes of the current process. @new is the set of credentials that will + * be installed. Modifications should be made to this rather than to + * @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setgroups(struct cred *new, const struct cred *old) { - return call_int_hook(task_fix_setgroups, 0, new, old); + return call_int_hook(task_fix_setgroups, new, old); } +/** + * security_task_setpgid() - Check if setting the pgid is allowed + * @p: task being modified + * @pgid: new pgid + * + * Check permission before setting the process group identifier of the process + * @p to @pgid. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setpgid(struct task_struct *p, pid_t pgid) { - return call_int_hook(task_setpgid, 0, p, pgid); + return call_int_hook(task_setpgid, p, pgid); } +/** + * security_task_getpgid() - Check if getting the pgid is allowed + * @p: task + * + * Check permission before getting the process group identifier of the process + * @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getpgid(struct task_struct *p) { - return call_int_hook(task_getpgid, 0, p); + return call_int_hook(task_getpgid, p); } +/** + * security_task_getsid() - Check if getting the session id is allowed + * @p: task + * + * Check permission before getting the session identifier of the process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getsid(struct task_struct *p) { - return call_int_hook(task_getsid, 0, p); + return call_int_hook(task_getsid, p); } -void security_current_getsecid_subj(u32 *secid) +/** + * security_current_getlsmprop_subj() - Current task's subjective LSM data + * @prop: lsm specific information + * + * Retrieve the subjective security identifier of the current task and return + * it in @prop. + */ +void security_current_getlsmprop_subj(struct lsm_prop *prop) { - *secid = 0; - call_void_hook(current_getsecid_subj, secid); + lsmprop_init(prop); + call_void_hook(current_getlsmprop_subj, prop); } -EXPORT_SYMBOL(security_current_getsecid_subj); +EXPORT_SYMBOL(security_current_getlsmprop_subj); -void security_task_getsecid_obj(struct task_struct *p, u32 *secid) +/** + * security_task_getlsmprop_obj() - Get a task's objective LSM data + * @p: target task + * @prop: lsm specific information + * + * Retrieve the objective security identifier of the task_struct in @p and + * return it in @prop. + */ +void security_task_getlsmprop_obj(struct task_struct *p, struct lsm_prop *prop) { - *secid = 0; - call_void_hook(task_getsecid_obj, p, secid); + lsmprop_init(prop); + call_void_hook(task_getlsmprop_obj, p, prop); } -EXPORT_SYMBOL(security_task_getsecid_obj); +EXPORT_SYMBOL(security_task_getlsmprop_obj); +/** + * security_task_setnice() - Check if setting a task's nice value is allowed + * @p: target task + * @nice: nice value + * + * Check permission before setting the nice value of @p to @nice. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setnice(struct task_struct *p, int nice) { - return call_int_hook(task_setnice, 0, p, nice); + return call_int_hook(task_setnice, p, nice); } +/** + * security_task_setioprio() - Check if setting a task's ioprio is allowed + * @p: target task + * @ioprio: ioprio value + * + * Check permission before setting the ioprio value of @p to @ioprio. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setioprio(struct task_struct *p, int ioprio) { - return call_int_hook(task_setioprio, 0, p, ioprio); + return call_int_hook(task_setioprio, p, ioprio); } +/** + * security_task_getioprio() - Check if getting a task's ioprio is allowed + * @p: task + * + * Check permission before getting the ioprio value of @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getioprio(struct task_struct *p) { - return call_int_hook(task_getioprio, 0, p); + return call_int_hook(task_getioprio, p); } +/** + * security_task_prlimit() - Check if get/setting resources limits is allowed + * @cred: current task credentials + * @tcred: target task credentials + * @flags: LSM_PRLIMIT_* flag bits indicating a get/set/both + * + * Check permission before getting and/or setting the resource limits of + * another task. + * + * Return: Returns 0 if permission is granted. + */ int security_task_prlimit(const struct cred *cred, const struct cred *tcred, unsigned int flags) { - return call_int_hook(task_prlimit, 0, cred, tcred, flags); + return call_int_hook(task_prlimit, cred, tcred, flags); } +/** + * security_task_setrlimit() - Check if setting a new rlimit value is allowed + * @p: target task's group leader + * @resource: resource whose limit is being set + * @new_rlim: new resource limit + * + * Check permission before setting the resource limits of process @p for + * @resource to @new_rlim. The old resource limit values can be examined by + * dereferencing (p->signal->rlim + resource). + * + * Return: Returns 0 if permission is granted. + */ int security_task_setrlimit(struct task_struct *p, unsigned int resource, - struct rlimit *new_rlim) + struct rlimit *new_rlim) { - return call_int_hook(task_setrlimit, 0, p, resource, new_rlim); + return call_int_hook(task_setrlimit, p, resource, new_rlim); } +/** + * security_task_setscheduler() - Check if setting sched policy/param is allowed + * @p: target task + * + * Check permission before setting scheduling policy and/or parameters of + * process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setscheduler(struct task_struct *p) { - return call_int_hook(task_setscheduler, 0, p); + return call_int_hook(task_setscheduler, p); } +/** + * security_task_getscheduler() - Check if getting scheduling info is allowed + * @p: target task + * + * Check permission before obtaining scheduling information for process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getscheduler(struct task_struct *p) { - return call_int_hook(task_getscheduler, 0, p); + return call_int_hook(task_getscheduler, p); } +/** + * security_task_movememory() - Check if moving memory is allowed + * @p: task + * + * Check permission before moving memory owned by process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_movememory(struct task_struct *p) { - return call_int_hook(task_movememory, 0, p); + return call_int_hook(task_movememory, p); } +/** + * security_task_kill() - Check if sending a signal is allowed + * @p: target process + * @info: signal information + * @sig: signal value + * @cred: credentials of the signal sender, NULL if @current + * + * Check permission before sending signal @sig to @p. @info can be NULL, the + * constant 1, or a pointer to a kernel_siginfo structure. If @info is 1 or + * SI_FROMKERNEL(info) is true, then the signal should be viewed as coming from + * the kernel and should typically be permitted. SIGIO signals are handled + * separately by the send_sigiotask hook in file_security_ops. + * + * Return: Returns 0 if permission is granted. + */ int security_task_kill(struct task_struct *p, struct kernel_siginfo *info, - int sig, const struct cred *cred) + int sig, const struct cred *cred) { - return call_int_hook(task_kill, 0, p, info, sig, cred); + return call_int_hook(task_kill, p, info, sig, cred); } +/** + * security_task_prctl() - Check if a prctl op is allowed + * @option: operation + * @arg2: argument + * @arg3: argument + * @arg4: argument + * @arg5: argument + * + * Check permission before performing a process control operation on the + * current process. + * + * Return: Return -ENOSYS if no-one wanted to handle this op, any other value + * to cause prctl() to return immediately with that value. + */ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, - unsigned long arg4, unsigned long arg5) + unsigned long arg4, unsigned long arg5) { int thisrc; int rc = LSM_RET_DEFAULT(task_prctl); - struct security_hook_list *hp; + struct lsm_static_call *scall; - hlist_for_each_entry(hp, &security_hook_heads.task_prctl, list) { - thisrc = hp->hook.task_prctl(option, arg2, arg3, arg4, arg5); + lsm_for_each_hook(scall, task_prctl) { + thisrc = scall->hl->hook.task_prctl(option, arg2, arg3, arg4, arg5); if (thisrc != LSM_RET_DEFAULT(task_prctl)) { rc = thisrc; if (thisrc != 0) @@ -1981,39 +3229,87 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, return rc; } +/** + * security_task_to_inode() - Set the security attributes of a task's inode + * @p: task + * @inode: inode + * + * Set the security attributes for an inode based on an associated task's + * security attributes, e.g. for /proc/pid inodes. + */ void security_task_to_inode(struct task_struct *p, struct inode *inode) { call_void_hook(task_to_inode, p, inode); } +/** + * security_create_user_ns() - Check if creating a new userns is allowed + * @cred: prepared creds + * + * Check permission prior to creating a new user namespace. + * + * Return: Returns 0 if successful, otherwise < 0 error code. + */ int security_create_user_ns(const struct cred *cred) { - return call_int_hook(userns_create, 0, cred); + return call_int_hook(userns_create, cred); } +/** + * security_ipc_permission() - Check if sysv ipc access is allowed + * @ipcp: ipc permission structure + * @flag: requested permissions + * + * Check permissions for access to IPC. + * + * Return: Returns 0 if permission is granted. + */ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag) { - return call_int_hook(ipc_permission, 0, ipcp, flag); + return call_int_hook(ipc_permission, ipcp, flag); } -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) +/** + * security_ipc_getlsmprop() - Get the sysv ipc object LSM data + * @ipcp: ipc permission structure + * @prop: pointer to lsm information + * + * Get the lsm information associated with the ipc object. + */ + +void security_ipc_getlsmprop(struct kern_ipc_perm *ipcp, struct lsm_prop *prop) { - *secid = 0; - call_void_hook(ipc_getsecid, ipcp, secid); + lsmprop_init(prop); + call_void_hook(ipc_getlsmprop, ipcp, prop); } +/** + * security_msg_msg_alloc() - Allocate a sysv ipc message LSM blob + * @msg: message structure + * + * Allocate and attach a security structure to the msg->security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Return 0 if operation was successful and permission is granted. + */ int security_msg_msg_alloc(struct msg_msg *msg) { int rc = lsm_msg_msg_alloc(msg); if (unlikely(rc)) return rc; - rc = call_int_hook(msg_msg_alloc_security, 0, msg); + rc = call_int_hook(msg_msg_alloc_security, msg); if (unlikely(rc)) security_msg_msg_free(msg); return rc; } +/** + * security_msg_msg_free() - Free a sysv ipc message LSM blob + * @msg: message structure + * + * Deallocate the security structure for this message. + */ void security_msg_msg_free(struct msg_msg *msg) { call_void_hook(msg_msg_free_security, msg); @@ -2021,18 +3317,33 @@ void security_msg_msg_free(struct msg_msg *msg) msg->security = NULL; } +/** + * security_msg_queue_alloc() - Allocate a sysv ipc msg queue LSM blob + * @msq: sysv ipc permission structure + * + * Allocate and attach a security structure to @msg. The security field is + * initialized to NULL when the structure is first created. + * + * Return: Returns 0 if operation was successful and permission is granted. + */ int security_msg_queue_alloc(struct kern_ipc_perm *msq) { int rc = lsm_ipc_alloc(msq); if (unlikely(rc)) return rc; - rc = call_int_hook(msg_queue_alloc_security, 0, msq); + rc = call_int_hook(msg_queue_alloc_security, msq); if (unlikely(rc)) security_msg_queue_free(msq); return rc; } +/** + * security_msg_queue_free() - Free a sysv ipc msg queue LSM blob + * @msq: sysv ipc permission structure + * + * Deallocate security field @perm->security for the message queue. + */ void security_msg_queue_free(struct kern_ipc_perm *msq) { call_void_hook(msg_queue_free_security, msq); @@ -2040,40 +3351,102 @@ void security_msg_queue_free(struct kern_ipc_perm *msq) msq->security = NULL; } +/** + * security_msg_queue_associate() - Check if a msg queue operation is allowed + * @msq: sysv ipc permission structure + * @msqflg: operation flags + * + * Check permission when a message queue is requested through the msgget system + * call. This hook is only called when returning the message queue identifier + * for an existing message queue, not when a new message queue is created. + * + * Return: Return 0 if permission is granted. + */ int security_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg) { - return call_int_hook(msg_queue_associate, 0, msq, msqflg); + return call_int_hook(msg_queue_associate, msq, msqflg); } +/** + * security_msg_queue_msgctl() - Check if a msg queue operation is allowed + * @msq: sysv ipc permission structure + * @cmd: operation + * + * Check permission when a message control operation specified by @cmd is to be + * performed on the message queue with permissions. + * + * Return: Returns 0 if permission is granted. + */ int security_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd) { - return call_int_hook(msg_queue_msgctl, 0, msq, cmd); + return call_int_hook(msg_queue_msgctl, msq, cmd); } +/** + * security_msg_queue_msgsnd() - Check if sending a sysv ipc message is allowed + * @msq: sysv ipc permission structure + * @msg: message + * @msqflg: operation flags + * + * Check permission before a message, @msg, is enqueued on the message queue + * with permissions specified in @msq. + * + * Return: Returns 0 if permission is granted. + */ int security_msg_queue_msgsnd(struct kern_ipc_perm *msq, - struct msg_msg *msg, int msqflg) + struct msg_msg *msg, int msqflg) { - return call_int_hook(msg_queue_msgsnd, 0, msq, msg, msqflg); + return call_int_hook(msg_queue_msgsnd, msq, msg, msqflg); } +/** + * security_msg_queue_msgrcv() - Check if receiving a sysv ipc msg is allowed + * @msq: sysv ipc permission structure + * @msg: message + * @target: target task + * @type: type of message requested + * @mode: operation flags + * + * Check permission before a message, @msg, is removed from the message queue. + * The @target task structure contains a pointer to the process that will be + * receiving the message (not equal to the current process when inline receives + * are being performed). + * + * Return: Returns 0 if permission is granted. + */ int security_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg, - struct task_struct *target, long type, int mode) + struct task_struct *target, long type, int mode) { - return call_int_hook(msg_queue_msgrcv, 0, msq, msg, target, type, mode); + return call_int_hook(msg_queue_msgrcv, msq, msg, target, type, mode); } +/** + * security_shm_alloc() - Allocate a sysv shm LSM blob + * @shp: sysv ipc permission structure + * + * Allocate and attach a security structure to the @shp security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Returns 0 if operation was successful and permission is granted. + */ int security_shm_alloc(struct kern_ipc_perm *shp) { int rc = lsm_ipc_alloc(shp); if (unlikely(rc)) return rc; - rc = call_int_hook(shm_alloc_security, 0, shp); + rc = call_int_hook(shm_alloc_security, shp); if (unlikely(rc)) security_shm_free(shp); return rc; } +/** + * security_shm_free() - Free a sysv shm LSM blob + * @shp: sysv ipc permission structure + * + * Deallocate the security structure @perm->security for the memory segment. + */ void security_shm_free(struct kern_ipc_perm *shp) { call_void_hook(shm_free_security, shp); @@ -2081,33 +3454,83 @@ void security_shm_free(struct kern_ipc_perm *shp) shp->security = NULL; } +/** + * security_shm_associate() - Check if a sysv shm operation is allowed + * @shp: sysv ipc permission structure + * @shmflg: operation flags + * + * Check permission when a shared memory region is requested through the shmget + * system call. This hook is only called when returning the shared memory + * region identifier for an existing region, not when a new shared memory + * region is created. + * + * Return: Returns 0 if permission is granted. + */ int security_shm_associate(struct kern_ipc_perm *shp, int shmflg) { - return call_int_hook(shm_associate, 0, shp, shmflg); + return call_int_hook(shm_associate, shp, shmflg); } +/** + * security_shm_shmctl() - Check if a sysv shm operation is allowed + * @shp: sysv ipc permission structure + * @cmd: operation + * + * Check permission when a shared memory control operation specified by @cmd is + * to be performed on the shared memory region with permissions in @shp. + * + * Return: Return 0 if permission is granted. + */ int security_shm_shmctl(struct kern_ipc_perm *shp, int cmd) { - return call_int_hook(shm_shmctl, 0, shp, cmd); + return call_int_hook(shm_shmctl, shp, cmd); } -int security_shm_shmat(struct kern_ipc_perm *shp, char __user *shmaddr, int shmflg) +/** + * security_shm_shmat() - Check if a sysv shm attach operation is allowed + * @shp: sysv ipc permission structure + * @shmaddr: address of memory region to attach + * @shmflg: operation flags + * + * Check permissions prior to allowing the shmat system call to attach the + * shared memory segment with permissions @shp to the data segment of the + * calling process. The attaching address is specified by @shmaddr. + * + * Return: Returns 0 if permission is granted. + */ +int security_shm_shmat(struct kern_ipc_perm *shp, + char __user *shmaddr, int shmflg) { - return call_int_hook(shm_shmat, 0, shp, shmaddr, shmflg); + return call_int_hook(shm_shmat, shp, shmaddr, shmflg); } +/** + * security_sem_alloc() - Allocate a sysv semaphore LSM blob + * @sma: sysv ipc permission structure + * + * Allocate and attach a security structure to the @sma security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Returns 0 if operation was successful and permission is granted. + */ int security_sem_alloc(struct kern_ipc_perm *sma) { int rc = lsm_ipc_alloc(sma); if (unlikely(rc)) return rc; - rc = call_int_hook(sem_alloc_security, 0, sma); + rc = call_int_hook(sem_alloc_security, sma); if (unlikely(rc)) security_sem_free(sma); return rc; } +/** + * security_sem_free() - Free a sysv semaphore LSM blob + * @sma: sysv ipc permission structure + * + * Deallocate security structure @sma->security for the semaphore. + */ void security_sem_free(struct kern_ipc_perm *sma) { call_void_hook(sem_free_security, sma); @@ -2115,22 +3538,62 @@ void security_sem_free(struct kern_ipc_perm *sma) sma->security = NULL; } +/** + * security_sem_associate() - Check if a sysv semaphore operation is allowed + * @sma: sysv ipc permission structure + * @semflg: operation flags + * + * Check permission when a semaphore is requested through the semget system + * call. This hook is only called when returning the semaphore identifier for + * an existing semaphore, not when a new one must be created. + * + * Return: Returns 0 if permission is granted. + */ int security_sem_associate(struct kern_ipc_perm *sma, int semflg) { - return call_int_hook(sem_associate, 0, sma, semflg); + return call_int_hook(sem_associate, sma, semflg); } +/** + * security_sem_semctl() - Check if a sysv semaphore operation is allowed + * @sma: sysv ipc permission structure + * @cmd: operation + * + * Check permission when a semaphore operation specified by @cmd is to be + * performed on the semaphore. + * + * Return: Returns 0 if permission is granted. + */ int security_sem_semctl(struct kern_ipc_perm *sma, int cmd) { - return call_int_hook(sem_semctl, 0, sma, cmd); + return call_int_hook(sem_semctl, sma, cmd); } +/** + * security_sem_semop() - Check if a sysv semaphore operation is allowed + * @sma: sysv ipc permission structure + * @sops: operations to perform + * @nsops: number of operations + * @alter: flag indicating changes will be made + * + * Check permissions before performing operations on members of the semaphore + * set. If the @alter flag is nonzero, the semaphore set may be modified. + * + * Return: Returns 0 if permission is granted. + */ int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops, - unsigned nsops, int alter) + unsigned nsops, int alter) { - return call_int_hook(sem_semop, 0, sma, sops, nsops, alter); + return call_int_hook(sem_semop, sma, sops, nsops, alter); } +/** + * security_d_instantiate() - Populate an inode's LSM state based on a dentry + * @dentry: dentry + * @inode: inode + * + * Fill in @inode security information for a @dentry if allowed. + */ void security_d_instantiate(struct dentry *dentry, struct inode *inode) { if (unlikely(inode && IS_PRIVATE(inode))) @@ -2139,245 +3602,848 @@ void security_d_instantiate(struct dentry *dentry, struct inode *inode) } EXPORT_SYMBOL(security_d_instantiate); -int security_getprocattr(struct task_struct *p, const char *lsm, - const char *name, char **value) +/* + * Please keep this in sync with it's counterpart in security/lsm_syscalls.c + */ + +/** + * security_getselfattr - Read an LSM attribute of the current process. + * @attr: which attribute to return + * @uctx: the user-space destination for the information, or NULL + * @size: pointer to the size of space available to receive the data + * @flags: special handling options. LSM_FLAG_SINGLE indicates that only + * attributes associated with the LSM identified in the passed @ctx be + * reported. + * + * A NULL value for @uctx can be used to get both the number of attributes + * and the size of the data. + * + * Returns the number of attributes found on success, negative value + * on error. @size is reset to the total size of the data. + * If @size is insufficient to contain the data -E2BIG is returned. + */ +int security_getselfattr(unsigned int attr, struct lsm_ctx __user *uctx, + u32 __user *size, u32 flags) +{ + struct lsm_static_call *scall; + struct lsm_ctx lctx = { .id = LSM_ID_UNDEF, }; + u8 __user *base = (u8 __user *)uctx; + u32 entrysize; + u32 total = 0; + u32 left; + bool toobig = false; + bool single = false; + int count = 0; + int rc; + + if (attr == LSM_ATTR_UNDEF) + return -EINVAL; + if (size == NULL) + return -EINVAL; + if (get_user(left, size)) + return -EFAULT; + + if (flags) { + /* + * Only flag supported is LSM_FLAG_SINGLE + */ + if (flags != LSM_FLAG_SINGLE || !uctx) + return -EINVAL; + if (copy_from_user(&lctx, uctx, sizeof(lctx))) + return -EFAULT; + /* + * If the LSM ID isn't specified it is an error. + */ + if (lctx.id == LSM_ID_UNDEF) + return -EINVAL; + single = true; + } + + /* + * In the usual case gather all the data from the LSMs. + * In the single case only get the data from the LSM specified. + */ + lsm_for_each_hook(scall, getselfattr) { + if (single && lctx.id != scall->hl->lsmid->id) + continue; + entrysize = left; + if (base) + uctx = (struct lsm_ctx __user *)(base + total); + rc = scall->hl->hook.getselfattr(attr, uctx, &entrysize, flags); + if (rc == -EOPNOTSUPP) + continue; + if (rc == -E2BIG) { + rc = 0; + left = 0; + toobig = true; + } else if (rc < 0) + return rc; + else + left -= entrysize; + + total += entrysize; + count += rc; + if (single) + break; + } + if (put_user(total, size)) + return -EFAULT; + if (toobig) + return -E2BIG; + if (count == 0) + return LSM_RET_DEFAULT(getselfattr); + return count; +} + +/* + * Please keep this in sync with it's counterpart in security/lsm_syscalls.c + */ + +/** + * security_setselfattr - Set an LSM attribute on the current process. + * @attr: which attribute to set + * @uctx: the user-space source for the information + * @size: the size of the data + * @flags: reserved for future use, must be 0 + * + * Set an LSM attribute for the current process. The LSM, attribute + * and new value are included in @uctx. + * + * Returns 0 on success, -EINVAL if the input is inconsistent, -EFAULT + * if the user buffer is inaccessible, E2BIG if size is too big, or an + * LSM specific failure. + */ +int security_setselfattr(unsigned int attr, struct lsm_ctx __user *uctx, + u32 size, u32 flags) +{ + struct lsm_static_call *scall; + struct lsm_ctx *lctx; + int rc = LSM_RET_DEFAULT(setselfattr); + u64 required_len; + + if (flags) + return -EINVAL; + if (size < sizeof(*lctx)) + return -EINVAL; + if (size > PAGE_SIZE) + return -E2BIG; + + lctx = memdup_user(uctx, size); + if (IS_ERR(lctx)) + return PTR_ERR(lctx); + + if (size < lctx->len || + check_add_overflow(sizeof(*lctx), lctx->ctx_len, &required_len) || + lctx->len < required_len) { + rc = -EINVAL; + goto free_out; + } + + lsm_for_each_hook(scall, setselfattr) + if ((scall->hl->lsmid->id) == lctx->id) { + rc = scall->hl->hook.setselfattr(attr, lctx, size, flags); + break; + } + +free_out: + kfree(lctx); + return rc; +} + +/** + * security_getprocattr() - Read an attribute for a task + * @p: the task + * @lsmid: LSM identification + * @name: attribute name + * @value: attribute value + * + * Read attribute @name for task @p and store it into @value if allowed. + * + * Return: Returns the length of @value on success, a negative value otherwise. + */ +int security_getprocattr(struct task_struct *p, int lsmid, const char *name, + char **value) { - struct security_hook_list *hp; + struct lsm_static_call *scall; - hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { - if (lsm != NULL && strcmp(lsm, hp->lsm)) + lsm_for_each_hook(scall, getprocattr) { + if (lsmid != 0 && lsmid != scall->hl->lsmid->id) continue; - return hp->hook.getprocattr(p, name, value); + return scall->hl->hook.getprocattr(p, name, value); } return LSM_RET_DEFAULT(getprocattr); } -int security_setprocattr(const char *lsm, const char *name, void *value, - size_t size) +/** + * security_setprocattr() - Set an attribute for a task + * @lsmid: LSM identification + * @name: attribute name + * @value: attribute value + * @size: attribute value size + * + * Write (set) the current task's attribute @name to @value, size @size if + * allowed. + * + * Return: Returns bytes written on success, a negative value otherwise. + */ +int security_setprocattr(int lsmid, const char *name, void *value, size_t size) { - struct security_hook_list *hp; + struct lsm_static_call *scall; - hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { - if (lsm != NULL && strcmp(lsm, hp->lsm)) + lsm_for_each_hook(scall, setprocattr) { + if (lsmid != 0 && lsmid != scall->hl->lsmid->id) continue; - return hp->hook.setprocattr(name, value, size); + return scall->hl->hook.setprocattr(name, value, size); } return LSM_RET_DEFAULT(setprocattr); } -int security_netlink_send(struct sock *sk, struct sk_buff *skb) +/** + * security_ismaclabel() - Check if the named attribute is a MAC label + * @name: full extended attribute name + * + * Check if the extended attribute specified by @name represents a MAC label. + * + * Return: Returns 1 if name is a MAC attribute otherwise returns 0. + */ +int security_ismaclabel(const char *name) { - return call_int_hook(netlink_send, 0, sk, skb); + return call_int_hook(ismaclabel, name); } +EXPORT_SYMBOL(security_ismaclabel); -int security_ismaclabel(const char *name) +/** + * security_secid_to_secctx() - Convert a secid to a secctx + * @secid: secid + * @cp: the LSM context + * + * Convert secid to security context. If @cp is NULL the length of the + * result will be returned, but no data will be returned. This + * does mean that the length could change between calls to check the length and + * the next call which actually allocates and returns the data. + * + * Return: Return length of data on success, error on failure. + */ +int security_secid_to_secctx(u32 secid, struct lsm_context *cp) { - return call_int_hook(ismaclabel, 0, name); + return call_int_hook(secid_to_secctx, secid, cp); } -EXPORT_SYMBOL(security_ismaclabel); +EXPORT_SYMBOL(security_secid_to_secctx); -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +/** + * security_lsmprop_to_secctx() - Convert a lsm_prop to a secctx + * @prop: lsm specific information + * @cp: the LSM context + * @lsmid: which security module to report + * + * Convert a @prop entry to security context. If @cp is NULL the + * length of the result will be returned. This does mean that the + * length could change between calls to check the length and the + * next call which actually allocates and returns the @cp. + * + * @lsmid identifies which LSM should supply the context. + * A value of LSM_ID_UNDEF indicates that the first LSM suppling + * the hook should be used. This is used in cases where the + * ID of the supplying LSM is unambiguous. + * + * Return: Return length of data on success, error on failure. + */ +int security_lsmprop_to_secctx(struct lsm_prop *prop, struct lsm_context *cp, + int lsmid) { - struct security_hook_list *hp; - int rc; + struct lsm_static_call *scall; - /* - * Currently, only one LSM can implement secid_to_secctx (i.e this - * LSM hook is not "stackable"). - */ - hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { - rc = hp->hook.secid_to_secctx(secid, secdata, seclen); - if (rc != LSM_RET_DEFAULT(secid_to_secctx)) - return rc; + lsm_for_each_hook(scall, lsmprop_to_secctx) { + if (lsmid != LSM_ID_UNDEF && lsmid != scall->hl->lsmid->id) + continue; + return scall->hl->hook.lsmprop_to_secctx(prop, cp); } - - return LSM_RET_DEFAULT(secid_to_secctx); + return LSM_RET_DEFAULT(lsmprop_to_secctx); } -EXPORT_SYMBOL(security_secid_to_secctx); +EXPORT_SYMBOL(security_lsmprop_to_secctx); +/** + * security_secctx_to_secid() - Convert a secctx to a secid + * @secdata: secctx + * @seclen: length of secctx + * @secid: secid + * + * Convert security context to secid. + * + * Return: Returns 0 on success, error on failure. + */ int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) { *secid = 0; - return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid); + return call_int_hook(secctx_to_secid, secdata, seclen, secid); } EXPORT_SYMBOL(security_secctx_to_secid); -void security_release_secctx(char *secdata, u32 seclen) +/** + * security_release_secctx() - Free a secctx buffer + * @cp: the security context + * + * Release the security context. + */ +void security_release_secctx(struct lsm_context *cp) { - call_void_hook(release_secctx, secdata, seclen); + call_void_hook(release_secctx, cp); + memset(cp, 0, sizeof(*cp)); } EXPORT_SYMBOL(security_release_secctx); +/** + * security_inode_invalidate_secctx() - Invalidate an inode's security label + * @inode: inode + * + * Notify the security module that it must revalidate the security context of + * an inode. + */ void security_inode_invalidate_secctx(struct inode *inode) { call_void_hook(inode_invalidate_secctx, inode); } EXPORT_SYMBOL(security_inode_invalidate_secctx); +/** + * security_inode_notifysecctx() - Notify the LSM of an inode's security label + * @inode: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * Notify the security module of what the security context of an inode should + * be. Initializes the incore security context managed by the security module + * for this inode. Example usage: NFS client invokes this hook to initialize + * the security context in its incore inode to the value provided by the server + * for the file when the server returned the file's attributes to the client. + * Must be called with inode->i_mutex locked. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) { - return call_int_hook(inode_notifysecctx, 0, inode, ctx, ctxlen); + return call_int_hook(inode_notifysecctx, inode, ctx, ctxlen); } EXPORT_SYMBOL(security_inode_notifysecctx); +/** + * security_inode_setsecctx() - Change the security label of an inode + * @dentry: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * Change the security context of an inode. Updates the incore security + * context managed by the security module and invokes the fs code as needed + * (via __vfs_setxattr_noperm) to update any backing xattrs that represent the + * context. Example usage: NFS server invokes this hook to change the security + * context in its incore inode and on the backing filesystem to a value + * provided by the client on a SETATTR operation. Must be called with + * inode->i_mutex locked. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) { - return call_int_hook(inode_setsecctx, 0, dentry, ctx, ctxlen); + return call_int_hook(inode_setsecctx, dentry, ctx, ctxlen); } EXPORT_SYMBOL(security_inode_setsecctx); -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +/** + * security_inode_getsecctx() - Get the security label of an inode + * @inode: inode + * @cp: security context + * + * On success, returns 0 and fills out @cp with the security context + * for the given @inode. + * + * Return: Returns 0 on success, error on failure. + */ +int security_inode_getsecctx(struct inode *inode, struct lsm_context *cp) { - return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen); + memset(cp, 0, sizeof(*cp)); + return call_int_hook(inode_getsecctx, inode, cp); } EXPORT_SYMBOL(security_inode_getsecctx); #ifdef CONFIG_WATCH_QUEUE +/** + * security_post_notification() - Check if a watch notification can be posted + * @w_cred: credentials of the task that set the watch + * @cred: credentials of the task which triggered the watch + * @n: the notification + * + * Check to see if a watch notification can be posted to a particular queue. + * + * Return: Returns 0 if permission is granted. + */ int security_post_notification(const struct cred *w_cred, const struct cred *cred, struct watch_notification *n) { - return call_int_hook(post_notification, 0, w_cred, cred, n); + return call_int_hook(post_notification, w_cred, cred, n); } #endif /* CONFIG_WATCH_QUEUE */ #ifdef CONFIG_KEY_NOTIFICATIONS +/** + * security_watch_key() - Check if a task is allowed to watch for key events + * @key: the key to watch + * + * Check to see if a process is allowed to watch for event notifications from + * a key or keyring. + * + * Return: Returns 0 if permission is granted. + */ int security_watch_key(struct key *key) { - return call_int_hook(watch_key, 0, key); + return call_int_hook(watch_key, key); } -#endif +#endif /* CONFIG_KEY_NOTIFICATIONS */ #ifdef CONFIG_SECURITY_NETWORK +/** + * security_netlink_send() - Save info and check if netlink sending is allowed + * @sk: sending socket + * @skb: netlink message + * + * Save security information for a netlink message so that permission checking + * can be performed when the message is processed. The security information + * can be saved using the eff_cap field of the netlink_skb_parms structure. + * Also may be used to provide fine grained control over message transmission. + * + * Return: Returns 0 if the information was successfully saved and message is + * allowed to be transmitted. + */ +int security_netlink_send(struct sock *sk, struct sk_buff *skb) +{ + return call_int_hook(netlink_send, sk, skb); +} -int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk) +/** + * security_unix_stream_connect() - Check if a AF_UNIX stream is allowed + * @sock: originating sock + * @other: peer sock + * @newsk: new sock + * + * Check permissions before establishing a Unix domain stream connection + * between @sock and @other. + * + * The @unix_stream_connect and @unix_may_send hooks were necessary because + * Linux provides an alternative to the conventional file name space for Unix + * domain sockets. Whereas binding and connecting to sockets in the file name + * space is mediated by the typical file permissions (and caught by the mknod + * and permission hooks in inode_security_ops), binding and connecting to + * sockets in the abstract name space is completely unmediated. Sufficient + * control of Unix domain sockets in the abstract name space isn't possible + * using only the socket layer hooks, since we need to know the actual target + * socket, which is not looked up until we are inside the af_unix code. + * + * Return: Returns 0 if permission is granted. + */ +int security_unix_stream_connect(struct sock *sock, struct sock *other, + struct sock *newsk) { - return call_int_hook(unix_stream_connect, 0, sock, other, newsk); + return call_int_hook(unix_stream_connect, sock, other, newsk); } EXPORT_SYMBOL(security_unix_stream_connect); +/** + * security_unix_may_send() - Check if AF_UNIX socket can send datagrams + * @sock: originating sock + * @other: peer sock + * + * Check permissions before connecting or sending datagrams from @sock to + * @other. + * + * The @unix_stream_connect and @unix_may_send hooks were necessary because + * Linux provides an alternative to the conventional file name space for Unix + * domain sockets. Whereas binding and connecting to sockets in the file name + * space is mediated by the typical file permissions (and caught by the mknod + * and permission hooks in inode_security_ops), binding and connecting to + * sockets in the abstract name space is completely unmediated. Sufficient + * control of Unix domain sockets in the abstract name space isn't possible + * using only the socket layer hooks, since we need to know the actual target + * socket, which is not looked up until we are inside the af_unix code. + * + * Return: Returns 0 if permission is granted. + */ int security_unix_may_send(struct socket *sock, struct socket *other) { - return call_int_hook(unix_may_send, 0, sock, other); + return call_int_hook(unix_may_send, sock, other); } EXPORT_SYMBOL(security_unix_may_send); +/** + * security_socket_create() - Check if creating a new socket is allowed + * @family: protocol family + * @type: communications type + * @protocol: requested protocol + * @kern: set to 1 if a kernel socket is requested + * + * Check permissions prior to creating a new socket. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_create(int family, int type, int protocol, int kern) { - return call_int_hook(socket_create, 0, family, type, protocol, kern); + return call_int_hook(socket_create, family, type, protocol, kern); } +/** + * security_socket_post_create() - Initialize a newly created socket + * @sock: socket + * @family: protocol family + * @type: communications type + * @protocol: requested protocol + * @kern: set to 1 if a kernel socket is requested + * + * This hook allows a module to update or allocate a per-socket security + * structure. Note that the security field was not added directly to the socket + * structure, but rather, the socket security information is stored in the + * associated inode. Typically, the inode alloc_security hook will allocate + * and attach security information to SOCK_INODE(sock)->i_security. This hook + * may be used to update the SOCK_INODE(sock)->i_security field with additional + * information that wasn't available when the inode was allocated. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_post_create(struct socket *sock, int family, int type, int protocol, int kern) { - return call_int_hook(socket_post_create, 0, sock, family, type, - protocol, kern); + return call_int_hook(socket_post_create, sock, family, type, + protocol, kern); } +/** + * security_socket_socketpair() - Check if creating a socketpair is allowed + * @socka: first socket + * @sockb: second socket + * + * Check permissions before creating a fresh pair of sockets. + * + * Return: Returns 0 if permission is granted and the connection was + * established. + */ int security_socket_socketpair(struct socket *socka, struct socket *sockb) { - return call_int_hook(socket_socketpair, 0, socka, sockb); + return call_int_hook(socket_socketpair, socka, sockb); } EXPORT_SYMBOL(security_socket_socketpair); -int security_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) +/** + * security_socket_bind() - Check if a socket bind operation is allowed + * @sock: socket + * @address: requested bind address + * @addrlen: length of address + * + * Check permission before socket protocol layer bind operation is performed + * and the socket @sock is bound to the address specified in the @address + * parameter. + * + * Return: Returns 0 if permission is granted. + */ +int security_socket_bind(struct socket *sock, + struct sockaddr *address, int addrlen) { - return call_int_hook(socket_bind, 0, sock, address, addrlen); + return call_int_hook(socket_bind, sock, address, addrlen); } -int security_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) +/** + * security_socket_connect() - Check if a socket connect operation is allowed + * @sock: socket + * @address: address of remote connection point + * @addrlen: length of address + * + * Check permission before socket protocol layer connect operation attempts to + * connect socket @sock to a remote address, @address. + * + * Return: Returns 0 if permission is granted. + */ +int security_socket_connect(struct socket *sock, + struct sockaddr *address, int addrlen) { - return call_int_hook(socket_connect, 0, sock, address, addrlen); + return call_int_hook(socket_connect, sock, address, addrlen); } +/** + * security_socket_listen() - Check if a socket is allowed to listen + * @sock: socket + * @backlog: connection queue size + * + * Check permission before socket protocol layer listen operation. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_listen(struct socket *sock, int backlog) { - return call_int_hook(socket_listen, 0, sock, backlog); + return call_int_hook(socket_listen, sock, backlog); } +/** + * security_socket_accept() - Check if a socket is allowed to accept connections + * @sock: listening socket + * @newsock: newly creation connection socket + * + * Check permission before accepting a new connection. Note that the new + * socket, @newsock, has been created and some information copied to it, but + * the accept operation has not actually been performed. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_accept(struct socket *sock, struct socket *newsock) { - return call_int_hook(socket_accept, 0, sock, newsock); + return call_int_hook(socket_accept, sock, newsock); } +/** + * security_socket_sendmsg() - Check if sending a message is allowed + * @sock: sending socket + * @msg: message to send + * @size: size of message + * + * Check permission before transmitting a message to another socket. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size) { - return call_int_hook(socket_sendmsg, 0, sock, msg, size); + return call_int_hook(socket_sendmsg, sock, msg, size); } +/** + * security_socket_recvmsg() - Check if receiving a message is allowed + * @sock: receiving socket + * @msg: message to receive + * @size: size of message + * @flags: operational flags + * + * Check permission before receiving a message from a socket. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_recvmsg(struct socket *sock, struct msghdr *msg, int size, int flags) { - return call_int_hook(socket_recvmsg, 0, sock, msg, size, flags); + return call_int_hook(socket_recvmsg, sock, msg, size, flags); } +/** + * security_socket_getsockname() - Check if reading the socket addr is allowed + * @sock: socket + * + * Check permission before reading the local address (name) of the socket + * object. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_getsockname(struct socket *sock) { - return call_int_hook(socket_getsockname, 0, sock); + return call_int_hook(socket_getsockname, sock); } +/** + * security_socket_getpeername() - Check if reading the peer's addr is allowed + * @sock: socket + * + * Check permission before the remote address (name) of a socket object. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_getpeername(struct socket *sock) { - return call_int_hook(socket_getpeername, 0, sock); + return call_int_hook(socket_getpeername, sock); } +/** + * security_socket_getsockopt() - Check if reading a socket option is allowed + * @sock: socket + * @level: option's protocol level + * @optname: option name + * + * Check permissions before retrieving the options associated with socket + * @sock. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_getsockopt(struct socket *sock, int level, int optname) { - return call_int_hook(socket_getsockopt, 0, sock, level, optname); + return call_int_hook(socket_getsockopt, sock, level, optname); } +/** + * security_socket_setsockopt() - Check if setting a socket option is allowed + * @sock: socket + * @level: option's protocol level + * @optname: option name + * + * Check permissions before setting the options associated with socket @sock. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_setsockopt(struct socket *sock, int level, int optname) { - return call_int_hook(socket_setsockopt, 0, sock, level, optname); + return call_int_hook(socket_setsockopt, sock, level, optname); } +/** + * security_socket_shutdown() - Checks if shutting down the socket is allowed + * @sock: socket + * @how: flag indicating how sends and receives are handled + * + * Checks permission before all or part of a connection on the socket @sock is + * shut down. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_shutdown(struct socket *sock, int how) { - return call_int_hook(socket_shutdown, 0, sock, how); + return call_int_hook(socket_shutdown, sock, how); } +/** + * security_sock_rcv_skb() - Check if an incoming network packet is allowed + * @sk: destination sock + * @skb: incoming packet + * + * Check permissions on incoming network packets. This hook is distinct from + * Netfilter's IP input hooks since it is the first time that the incoming + * sk_buff @skb has been associated with a particular socket, @sk. Must not + * sleep inside this hook because some callers hold spinlocks. + * + * Return: Returns 0 if permission is granted. + */ int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { - return call_int_hook(socket_sock_rcv_skb, 0, sk, skb); + return call_int_hook(socket_sock_rcv_skb, sk, skb); } EXPORT_SYMBOL(security_sock_rcv_skb); +/** + * security_socket_getpeersec_stream() - Get the remote peer label + * @sock: socket + * @optval: destination buffer + * @optlen: size of peer label copied into the buffer + * @len: maximum size of the destination buffer + * + * This hook allows the security module to provide peer socket security state + * for unix or connected tcp sockets to userspace via getsockopt SO_GETPEERSEC. + * For tcp sockets this can be meaningful if the socket is associated with an + * ipsec SA. + * + * Return: Returns 0 if all is well, otherwise, typical getsockopt return + * values. + */ int security_socket_getpeersec_stream(struct socket *sock, sockptr_t optval, sockptr_t optlen, unsigned int len) { - return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock, - optval, optlen, len); + return call_int_hook(socket_getpeersec_stream, sock, optval, optlen, + len); } -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +/** + * security_socket_getpeersec_dgram() - Get the remote peer label + * @sock: socket + * @skb: datagram packet + * @secid: remote peer label secid + * + * This hook allows the security module to provide peer socket security state + * for udp sockets on a per-packet basis to userspace via getsockopt + * SO_GETPEERSEC. The application must first have indicated the IP_PASSSEC + * option via getsockopt. It can then retrieve the security state returned by + * this hook for a packet via the SCM_SECURITY ancillary message type. + * + * Return: Returns 0 on success, error on failure. + */ +int security_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) { - return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock, - skb, secid); + return call_int_hook(socket_getpeersec_dgram, sock, skb, secid); } EXPORT_SYMBOL(security_socket_getpeersec_dgram); +/** + * lsm_sock_alloc - allocate a composite sock blob + * @sock: the sock that needs a blob + * @gfp: allocation mode + * + * Allocate the sock blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_sock_alloc(struct sock *sock, gfp_t gfp) +{ + return lsm_blob_alloc(&sock->sk_security, blob_sizes.lbs_sock, gfp); +} + +/** + * security_sk_alloc() - Allocate and initialize a sock's LSM blob + * @sk: sock + * @family: protocol family + * @priority: gfp flags + * + * Allocate and attach a security structure to the sk->sk_security field, which + * is used to copy security attributes between local stream sockets. + * + * Return: Returns 0 on success, error on failure. + */ int security_sk_alloc(struct sock *sk, int family, gfp_t priority) { - return call_int_hook(sk_alloc_security, 0, sk, family, priority); + int rc = lsm_sock_alloc(sk, priority); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(sk_alloc_security, sk, family, priority); + if (unlikely(rc)) + security_sk_free(sk); + return rc; } +/** + * security_sk_free() - Free the sock's LSM blob + * @sk: sock + * + * Deallocate security structure. + */ void security_sk_free(struct sock *sk) { call_void_hook(sk_free_security, sk); + kfree(sk->sk_security); + sk->sk_security = NULL; } +/** + * security_sk_clone() - Clone a sock's LSM state + * @sk: original sock + * @newsk: target sock + * + * Clone/copy security structure. + */ void security_sk_clone(const struct sock *sk, struct sock *newsk) { call_void_hook(sk_clone_security, sk, newsk); } EXPORT_SYMBOL(security_sk_clone); -void security_sk_classify_flow(struct sock *sk, struct flowi_common *flic) +/** + * security_sk_classify_flow() - Set a flow's secid based on socket + * @sk: original socket + * @flic: target flow + * + * Set the target flow's secid to socket's secid. + */ +void security_sk_classify_flow(const struct sock *sk, struct flowi_common *flic) { call_void_hook(sk_getsecid, sk, &flic->flowic_secid); } EXPORT_SYMBOL(security_sk_classify_flow); +/** + * security_req_classify_flow() - Set a flow's secid based on request_sock + * @req: request_sock + * @flic: target flow + * + * Sets @flic's secid to @req's secid. + */ void security_req_classify_flow(const struct request_sock *req, struct flowi_common *flic) { @@ -2385,100 +4451,243 @@ void security_req_classify_flow(const struct request_sock *req, } EXPORT_SYMBOL(security_req_classify_flow); +/** + * security_sock_graft() - Reconcile LSM state when grafting a sock on a socket + * @sk: sock being grafted + * @parent: target parent socket + * + * Sets @parent's inode secid to @sk's secid and update @sk with any necessary + * LSM state from @parent. + */ void security_sock_graft(struct sock *sk, struct socket *parent) { call_void_hook(sock_graft, sk, parent); } EXPORT_SYMBOL(security_sock_graft); +/** + * security_inet_conn_request() - Set request_sock state using incoming connect + * @sk: parent listening sock + * @skb: incoming connection + * @req: new request_sock + * + * Initialize the @req LSM state based on @sk and the incoming connect in @skb. + * + * Return: Returns 0 if permission is granted. + */ int security_inet_conn_request(const struct sock *sk, - struct sk_buff *skb, struct request_sock *req) + struct sk_buff *skb, struct request_sock *req) { - return call_int_hook(inet_conn_request, 0, sk, skb, req); + return call_int_hook(inet_conn_request, sk, skb, req); } EXPORT_SYMBOL(security_inet_conn_request); +/** + * security_inet_csk_clone() - Set new sock LSM state based on request_sock + * @newsk: new sock + * @req: connection request_sock + * + * Set that LSM state of @sock using the LSM state from @req. + */ void security_inet_csk_clone(struct sock *newsk, - const struct request_sock *req) + const struct request_sock *req) { call_void_hook(inet_csk_clone, newsk, req); } +/** + * security_inet_conn_established() - Update sock's LSM state with connection + * @sk: sock + * @skb: connection packet + * + * Update @sock's LSM state to represent a new connection from @skb. + */ void security_inet_conn_established(struct sock *sk, - struct sk_buff *skb) + struct sk_buff *skb) { call_void_hook(inet_conn_established, sk, skb); } EXPORT_SYMBOL(security_inet_conn_established); +/** + * security_secmark_relabel_packet() - Check if setting a secmark is allowed + * @secid: new secmark value + * + * Check if the process should be allowed to relabel packets to @secid. + * + * Return: Returns 0 if permission is granted. + */ int security_secmark_relabel_packet(u32 secid) { - return call_int_hook(secmark_relabel_packet, 0, secid); + return call_int_hook(secmark_relabel_packet, secid); } EXPORT_SYMBOL(security_secmark_relabel_packet); +/** + * security_secmark_refcount_inc() - Increment the secmark labeling rule count + * + * Tells the LSM to increment the number of secmark labeling rules loaded. + */ void security_secmark_refcount_inc(void) { call_void_hook(secmark_refcount_inc); } EXPORT_SYMBOL(security_secmark_refcount_inc); +/** + * security_secmark_refcount_dec() - Decrement the secmark labeling rule count + * + * Tells the LSM to decrement the number of secmark labeling rules loaded. + */ void security_secmark_refcount_dec(void) { call_void_hook(secmark_refcount_dec); } EXPORT_SYMBOL(security_secmark_refcount_dec); +/** + * security_tun_dev_alloc_security() - Allocate a LSM blob for a TUN device + * @security: pointer to the LSM blob + * + * This hook allows a module to allocate a security structure for a TUN device, + * returning the pointer in @security. + * + * Return: Returns a zero on success, negative values on failure. + */ int security_tun_dev_alloc_security(void **security) { - return call_int_hook(tun_dev_alloc_security, 0, security); + int rc; + + rc = lsm_blob_alloc(security, blob_sizes.lbs_tun_dev, GFP_KERNEL); + if (rc) + return rc; + + rc = call_int_hook(tun_dev_alloc_security, *security); + if (rc) { + kfree(*security); + *security = NULL; + } + return rc; } EXPORT_SYMBOL(security_tun_dev_alloc_security); +/** + * security_tun_dev_free_security() - Free a TUN device LSM blob + * @security: LSM blob + * + * This hook allows a module to free the security structure for a TUN device. + */ void security_tun_dev_free_security(void *security) { - call_void_hook(tun_dev_free_security, security); + kfree(security); } EXPORT_SYMBOL(security_tun_dev_free_security); +/** + * security_tun_dev_create() - Check if creating a TUN device is allowed + * + * Check permissions prior to creating a new TUN device. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_create(void) { - return call_int_hook(tun_dev_create, 0); + return call_int_hook(tun_dev_create); } EXPORT_SYMBOL(security_tun_dev_create); +/** + * security_tun_dev_attach_queue() - Check if attaching a TUN queue is allowed + * @security: TUN device LSM blob + * + * Check permissions prior to attaching to a TUN device queue. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_attach_queue(void *security) { - return call_int_hook(tun_dev_attach_queue, 0, security); + return call_int_hook(tun_dev_attach_queue, security); } EXPORT_SYMBOL(security_tun_dev_attach_queue); +/** + * security_tun_dev_attach() - Update TUN device LSM state on attach + * @sk: associated sock + * @security: TUN device LSM blob + * + * This hook can be used by the module to update any security state associated + * with the TUN device's sock structure. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_attach(struct sock *sk, void *security) { - return call_int_hook(tun_dev_attach, 0, sk, security); + return call_int_hook(tun_dev_attach, sk, security); } EXPORT_SYMBOL(security_tun_dev_attach); +/** + * security_tun_dev_open() - Update TUN device LSM state on open + * @security: TUN device LSM blob + * + * This hook can be used by the module to update any security state associated + * with the TUN device's security structure. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_open(void *security) { - return call_int_hook(tun_dev_open, 0, security); + return call_int_hook(tun_dev_open, security); } EXPORT_SYMBOL(security_tun_dev_open); -int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) +/** + * security_sctp_assoc_request() - Update the LSM on a SCTP association req + * @asoc: SCTP association + * @skb: packet requesting the association + * + * Passes the @asoc and @chunk->skb of the association INIT packet to the LSM. + * + * Return: Returns 0 on success, error on failure. + */ +int security_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) { - return call_int_hook(sctp_assoc_request, 0, asoc, skb); + return call_int_hook(sctp_assoc_request, asoc, skb); } EXPORT_SYMBOL(security_sctp_assoc_request); +/** + * security_sctp_bind_connect() - Validate a list of addrs for a SCTP option + * @sk: socket + * @optname: SCTP option to validate + * @address: list of IP addresses to validate + * @addrlen: length of the address list + * + * Validiate permissions required for each address associated with sock @sk. + * Depending on @optname, the addresses will be treated as either a connect or + * bind service. The @addrlen is calculated on each IPv4 and IPv6 address using + * sizeof(struct sockaddr_in) or sizeof(struct sockaddr_in6). + * + * Return: Returns 0 on success, error on failure. + */ int security_sctp_bind_connect(struct sock *sk, int optname, struct sockaddr *address, int addrlen) { - return call_int_hook(sctp_bind_connect, 0, sk, optname, - address, addrlen); + return call_int_hook(sctp_bind_connect, sk, optname, address, addrlen); } EXPORT_SYMBOL(security_sctp_bind_connect); +/** + * security_sctp_sk_clone() - Clone a SCTP sock's LSM state + * @asoc: SCTP association + * @sk: original sock + * @newsk: target sock + * + * Called whenever a new socket is created by accept(2) (i.e. a TCP style + * socket) or when a socket is 'peeled off' e.g userspace calls + * sctp_peeloff(3). + */ void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk) { @@ -2486,103 +4695,268 @@ void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, } EXPORT_SYMBOL(security_sctp_sk_clone); +/** + * security_sctp_assoc_established() - Update LSM state when assoc established + * @asoc: SCTP association + * @skb: packet establishing the association + * + * Passes the @asoc and @chunk->skb of the association COOKIE_ACK packet to the + * security module. + * + * Return: Returns 0 if permission is granted. + */ int security_sctp_assoc_established(struct sctp_association *asoc, struct sk_buff *skb) { - return call_int_hook(sctp_assoc_established, 0, asoc, skb); + return call_int_hook(sctp_assoc_established, asoc, skb); } EXPORT_SYMBOL(security_sctp_assoc_established); +/** + * security_mptcp_add_subflow() - Inherit the LSM label from the MPTCP socket + * @sk: the owning MPTCP socket + * @ssk: the new subflow + * + * Update the labeling for the given MPTCP subflow, to match the one of the + * owning MPTCP socket. This hook has to be called after the socket creation and + * initialization via the security_socket_create() and + * security_socket_post_create() LSM hooks. + * + * Return: Returns 0 on success or a negative error code on failure. + */ +int security_mptcp_add_subflow(struct sock *sk, struct sock *ssk) +{ + return call_int_hook(mptcp_add_subflow, sk, ssk); +} + #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_INFINIBAND - +/** + * security_ib_pkey_access() - Check if access to an IB pkey is allowed + * @sec: LSM blob + * @subnet_prefix: subnet prefix of the port + * @pkey: IB pkey + * + * Check permission to access a pkey when modifying a QP. + * + * Return: Returns 0 if permission is granted. + */ int security_ib_pkey_access(void *sec, u64 subnet_prefix, u16 pkey) { - return call_int_hook(ib_pkey_access, 0, sec, subnet_prefix, pkey); + return call_int_hook(ib_pkey_access, sec, subnet_prefix, pkey); } EXPORT_SYMBOL(security_ib_pkey_access); -int security_ib_endport_manage_subnet(void *sec, const char *dev_name, u8 port_num) +/** + * security_ib_endport_manage_subnet() - Check if SMPs traffic is allowed + * @sec: LSM blob + * @dev_name: IB device name + * @port_num: port number + * + * Check permissions to send and receive SMPs on a end port. + * + * Return: Returns 0 if permission is granted. + */ +int security_ib_endport_manage_subnet(void *sec, + const char *dev_name, u8 port_num) { - return call_int_hook(ib_endport_manage_subnet, 0, sec, dev_name, port_num); + return call_int_hook(ib_endport_manage_subnet, sec, dev_name, port_num); } EXPORT_SYMBOL(security_ib_endport_manage_subnet); +/** + * security_ib_alloc_security() - Allocate an Infiniband LSM blob + * @sec: LSM blob + * + * Allocate a security structure for Infiniband objects. + * + * Return: Returns 0 on success, non-zero on failure. + */ int security_ib_alloc_security(void **sec) { - return call_int_hook(ib_alloc_security, 0, sec); + int rc; + + rc = lsm_blob_alloc(sec, blob_sizes.lbs_ib, GFP_KERNEL); + if (rc) + return rc; + + rc = call_int_hook(ib_alloc_security, *sec); + if (rc) { + kfree(*sec); + *sec = NULL; + } + return rc; } EXPORT_SYMBOL(security_ib_alloc_security); +/** + * security_ib_free_security() - Free an Infiniband LSM blob + * @sec: LSM blob + * + * Deallocate an Infiniband security structure. + */ void security_ib_free_security(void *sec) { - call_void_hook(ib_free_security, sec); + kfree(sec); } EXPORT_SYMBOL(security_ib_free_security); #endif /* CONFIG_SECURITY_INFINIBAND */ #ifdef CONFIG_SECURITY_NETWORK_XFRM - +/** + * security_xfrm_policy_alloc() - Allocate a xfrm policy LSM blob + * @ctxp: xfrm security context being added to the SPD + * @sec_ctx: security label provided by userspace + * @gfp: gfp flags + * + * Allocate a security structure to the xp->security field; the security field + * is initialized to NULL when the xfrm_policy is allocated. + * + * Return: Return 0 if operation was successful. + */ int security_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, struct xfrm_user_sec_ctx *sec_ctx, gfp_t gfp) { - return call_int_hook(xfrm_policy_alloc_security, 0, ctxp, sec_ctx, gfp); + return call_int_hook(xfrm_policy_alloc_security, ctxp, sec_ctx, gfp); } EXPORT_SYMBOL(security_xfrm_policy_alloc); +/** + * security_xfrm_policy_clone() - Clone xfrm policy LSM state + * @old_ctx: xfrm security context + * @new_ctxp: target xfrm security context + * + * Allocate a security structure in new_ctxp that contains the information from + * the old_ctx structure. + * + * Return: Return 0 if operation was successful. + */ int security_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, - struct xfrm_sec_ctx **new_ctxp) + struct xfrm_sec_ctx **new_ctxp) { - return call_int_hook(xfrm_policy_clone_security, 0, old_ctx, new_ctxp); + return call_int_hook(xfrm_policy_clone_security, old_ctx, new_ctxp); } +/** + * security_xfrm_policy_free() - Free a xfrm security context + * @ctx: xfrm security context + * + * Free LSM resources associated with @ctx. + */ void security_xfrm_policy_free(struct xfrm_sec_ctx *ctx) { call_void_hook(xfrm_policy_free_security, ctx); } EXPORT_SYMBOL(security_xfrm_policy_free); +/** + * security_xfrm_policy_delete() - Check if deleting a xfrm policy is allowed + * @ctx: xfrm security context + * + * Authorize deletion of a SPD entry. + * + * Return: Returns 0 if permission is granted. + */ int security_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) { - return call_int_hook(xfrm_policy_delete_security, 0, ctx); + return call_int_hook(xfrm_policy_delete_security, ctx); } +/** + * security_xfrm_state_alloc() - Allocate a xfrm state LSM blob + * @x: xfrm state being added to the SAD + * @sec_ctx: security label provided by userspace + * + * Allocate a security structure to the @x->security field; the security field + * is initialized to NULL when the xfrm_state is allocated. Set the context to + * correspond to @sec_ctx. + * + * Return: Return 0 if operation was successful. + */ int security_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *sec_ctx) { - return call_int_hook(xfrm_state_alloc, 0, x, sec_ctx); + return call_int_hook(xfrm_state_alloc, x, sec_ctx); } EXPORT_SYMBOL(security_xfrm_state_alloc); +/** + * security_xfrm_state_alloc_acquire() - Allocate a xfrm state LSM blob + * @x: xfrm state being added to the SAD + * @polsec: associated policy's security context + * @secid: secid from the flow + * + * Allocate a security structure to the x->security field; the security field + * is initialized to NULL when the xfrm_state is allocated. Set the context to + * correspond to secid. + * + * Return: Returns 0 if operation was successful. + */ int security_xfrm_state_alloc_acquire(struct xfrm_state *x, struct xfrm_sec_ctx *polsec, u32 secid) { - return call_int_hook(xfrm_state_alloc_acquire, 0, x, polsec, secid); + return call_int_hook(xfrm_state_alloc_acquire, x, polsec, secid); } +/** + * security_xfrm_state_delete() - Check if deleting a xfrm state is allowed + * @x: xfrm state + * + * Authorize deletion of x->security. + * + * Return: Returns 0 if permission is granted. + */ int security_xfrm_state_delete(struct xfrm_state *x) { - return call_int_hook(xfrm_state_delete_security, 0, x); + return call_int_hook(xfrm_state_delete_security, x); } EXPORT_SYMBOL(security_xfrm_state_delete); +/** + * security_xfrm_state_free() - Free a xfrm state + * @x: xfrm state + * + * Deallocate x->security. + */ void security_xfrm_state_free(struct xfrm_state *x) { call_void_hook(xfrm_state_free_security, x); } +/** + * security_xfrm_policy_lookup() - Check if using a xfrm policy is allowed + * @ctx: target xfrm security context + * @fl_secid: flow secid used to authorize access + * + * Check permission when a flow selects a xfrm_policy for processing XFRMs on a + * packet. The hook is called when selecting either a per-socket policy or a + * generic xfrm policy. + * + * Return: Return 0 if permission is granted, -ESRCH otherwise, or -errno on + * other errors. + */ int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid) { - return call_int_hook(xfrm_policy_lookup, 0, ctx, fl_secid); + return call_int_hook(xfrm_policy_lookup, ctx, fl_secid); } +/** + * security_xfrm_state_pol_flow_match() - Check for a xfrm match + * @x: xfrm state to match + * @xp: xfrm policy to check for a match + * @flic: flow to check for a match. + * + * Check @xp and @flic for a match with @x. + * + * Return: Returns 1 if there is a match. + */ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *xp, const struct flowi_common *flic) { - struct security_hook_list *hp; + struct lsm_static_call *scall; int rc = LSM_RET_DEFAULT(xfrm_state_pol_flow_match); /* @@ -2594,156 +4968,628 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, * For speed optimization, we explicitly break the loop rather than * using the macro */ - hlist_for_each_entry(hp, &security_hook_heads.xfrm_state_pol_flow_match, - list) { - rc = hp->hook.xfrm_state_pol_flow_match(x, xp, flic); + lsm_for_each_hook(scall, xfrm_state_pol_flow_match) { + rc = scall->hl->hook.xfrm_state_pol_flow_match(x, xp, flic); break; } return rc; } +/** + * security_xfrm_decode_session() - Determine the xfrm secid for a packet + * @skb: xfrm packet + * @secid: secid + * + * Decode the packet in @skb and return the security label in @secid. + * + * Return: Return 0 if all xfrms used have the same secid. + */ int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid) { - return call_int_hook(xfrm_decode_session, 0, skb, secid, 1); + return call_int_hook(xfrm_decode_session, skb, secid, 1); } void security_skb_classify_flow(struct sk_buff *skb, struct flowi_common *flic) { - int rc = call_int_hook(xfrm_decode_session, 0, skb, &flic->flowic_secid, - 0); + int rc = call_int_hook(xfrm_decode_session, skb, &flic->flowic_secid, + 0); BUG_ON(rc); } EXPORT_SYMBOL(security_skb_classify_flow); - #endif /* CONFIG_SECURITY_NETWORK_XFRM */ #ifdef CONFIG_KEYS - +/** + * security_key_alloc() - Allocate and initialize a kernel key LSM blob + * @key: key + * @cred: credentials + * @flags: allocation flags + * + * Permit allocation of a key and assign security data. Note that key does not + * have a serial number assigned at this point. + * + * Return: Return 0 if permission is granted, -ve error otherwise. + */ int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { - return call_int_hook(key_alloc, 0, key, cred, flags); + int rc = lsm_key_alloc(key); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(key_alloc, key, cred, flags); + if (unlikely(rc)) + security_key_free(key); + return rc; } +/** + * security_key_free() - Free a kernel key LSM blob + * @key: key + * + * Notification of destruction; free security data. + */ void security_key_free(struct key *key) { - call_void_hook(key_free, key); + kfree(key->security); + key->security = NULL; } +/** + * security_key_permission() - Check if a kernel key operation is allowed + * @key_ref: key reference + * @cred: credentials of actor requesting access + * @need_perm: requested permissions + * + * See whether a specific operational right is granted to a process on a key. + * + * Return: Return 0 if permission is granted, -ve error otherwise. + */ int security_key_permission(key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm) { - return call_int_hook(key_permission, 0, key_ref, cred, need_perm); + return call_int_hook(key_permission, key_ref, cred, need_perm); } -int security_key_getsecurity(struct key *key, char **_buffer) +/** + * security_key_getsecurity() - Get the key's security label + * @key: key + * @buffer: security label buffer + * + * Get a textual representation of the security context attached to a key for + * the purposes of honouring KEYCTL_GETSECURITY. This function allocates the + * storage for the NUL-terminated string and the caller should free it. + * + * Return: Returns the length of @buffer (including terminating NUL) or -ve if + * an error occurs. May also return 0 (and a NULL buffer pointer) if + * there is no security label assigned to the key. + */ +int security_key_getsecurity(struct key *key, char **buffer) { - *_buffer = NULL; - return call_int_hook(key_getsecurity, 0, key, _buffer); + *buffer = NULL; + return call_int_hook(key_getsecurity, key, buffer); } +/** + * security_key_post_create_or_update() - Notification of key create or update + * @keyring: keyring to which the key is linked to + * @key: created or updated key + * @payload: data used to instantiate or update the key + * @payload_len: length of payload + * @flags: key flags + * @create: flag indicating whether the key was created or updated + * + * Notify the caller of a key creation or update. + */ +void security_key_post_create_or_update(struct key *keyring, struct key *key, + const void *payload, size_t payload_len, + unsigned long flags, bool create) +{ + call_void_hook(key_post_create_or_update, keyring, key, payload, + payload_len, flags, create); +} #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT - -int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) +/** + * security_audit_rule_init() - Allocate and init an LSM audit rule struct + * @field: audit action + * @op: rule operator + * @rulestr: rule context + * @lsmrule: receive buffer for audit rule struct + * @gfp: GFP flag used for kmalloc + * + * Allocate and initialize an LSM audit rule structure. + * + * Return: Return 0 if @lsmrule has been successfully set, -EINVAL in case of + * an invalid rule. + */ +int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule, + gfp_t gfp) { - return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule); + return call_int_hook(audit_rule_init, field, op, rulestr, lsmrule, gfp); } +/** + * security_audit_rule_known() - Check if an audit rule contains LSM fields + * @krule: audit rule + * + * Specifies whether given @krule contains any fields related to the current + * LSM. + * + * Return: Returns 1 in case of relation found, 0 otherwise. + */ int security_audit_rule_known(struct audit_krule *krule) { - return call_int_hook(audit_rule_known, 0, krule); + return call_int_hook(audit_rule_known, krule); } +/** + * security_audit_rule_free() - Free an LSM audit rule struct + * @lsmrule: audit rule struct + * + * Deallocate the LSM audit rule structure previously allocated by + * audit_rule_init(). + */ void security_audit_rule_free(void *lsmrule) { call_void_hook(audit_rule_free, lsmrule); } -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule) +/** + * security_audit_rule_match() - Check if a label matches an audit rule + * @prop: security label + * @field: LSM audit field + * @op: matching operator + * @lsmrule: audit rule + * + * Determine if given @secid matches a rule previously approved by + * security_audit_rule_known(). + * + * Return: Returns 1 if secid matches the rule, 0 if it does not, -ERRNO on + * failure. + */ +int security_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, + void *lsmrule) { - return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule); + return call_int_hook(audit_rule_match, prop, field, op, lsmrule); } #endif /* CONFIG_AUDIT */ #ifdef CONFIG_BPF_SYSCALL -int security_bpf(int cmd, union bpf_attr *attr, unsigned int size) +/** + * security_bpf() - Check if the bpf syscall operation is allowed + * @cmd: command + * @attr: bpf attribute + * @size: size + * @kernel: whether or not call originated from kernel + * + * Do a initial check for all bpf syscalls after the attribute is copied into + * the kernel. The actual security module can implement their own rules to + * check the specific cmd they need. + * + * Return: Returns 0 if permission is granted. + */ +int security_bpf(int cmd, union bpf_attr *attr, unsigned int size, bool kernel) { - return call_int_hook(bpf, 0, cmd, attr, size); + return call_int_hook(bpf, cmd, attr, size, kernel); } + +/** + * security_bpf_map() - Check if access to a bpf map is allowed + * @map: bpf map + * @fmode: mode + * + * Do a check when the kernel generates and returns a file descriptor for eBPF + * maps. + * + * Return: Returns 0 if permission is granted. + */ int security_bpf_map(struct bpf_map *map, fmode_t fmode) { - return call_int_hook(bpf_map, 0, map, fmode); + return call_int_hook(bpf_map, map, fmode); } + +/** + * security_bpf_prog() - Check if access to a bpf program is allowed + * @prog: bpf program + * + * Do a check when the kernel generates and returns a file descriptor for eBPF + * programs. + * + * Return: Returns 0 if permission is granted. + */ int security_bpf_prog(struct bpf_prog *prog) { - return call_int_hook(bpf_prog, 0, prog); + return call_int_hook(bpf_prog, prog); } -int security_bpf_map_alloc(struct bpf_map *map) + +/** + * security_bpf_map_create() - Check if BPF map creation is allowed + * @map: BPF map object + * @attr: BPF syscall attributes used to create BPF map + * @token: BPF token used to grant user access + * @kernel: whether or not call originated from kernel + * + * Do a check when the kernel creates a new BPF map. This is also the + * point where LSM blob is allocated for LSMs that need them. + * + * Return: Returns 0 on success, error on failure. + */ +int security_bpf_map_create(struct bpf_map *map, union bpf_attr *attr, + struct bpf_token *token, bool kernel) { - return call_int_hook(bpf_map_alloc_security, 0, map); + int rc; + + rc = lsm_bpf_map_alloc(map); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bpf_map_create, map, attr, token, kernel); + if (unlikely(rc)) + security_bpf_map_free(map); + return rc; } -int security_bpf_prog_alloc(struct bpf_prog_aux *aux) + +/** + * security_bpf_prog_load() - Check if loading of BPF program is allowed + * @prog: BPF program object + * @attr: BPF syscall attributes used to create BPF program + * @token: BPF token used to grant user access to BPF subsystem + * @kernel: whether or not call originated from kernel + * + * Perform an access control check when the kernel loads a BPF program and + * allocates associated BPF program object. This hook is also responsible for + * allocating any required LSM state for the BPF program. + * + * Return: Returns 0 on success, error on failure. + */ +int security_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr, + struct bpf_token *token, bool kernel) +{ + int rc; + + rc = lsm_bpf_prog_alloc(prog); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bpf_prog_load, prog, attr, token, kernel); + if (unlikely(rc)) + security_bpf_prog_free(prog); + return rc; +} + +/** + * security_bpf_token_create() - Check if creating of BPF token is allowed + * @token: BPF token object + * @attr: BPF syscall attributes used to create BPF token + * @path: path pointing to BPF FS mount point from which BPF token is created + * + * Do a check when the kernel instantiates a new BPF token object from BPF FS + * instance. This is also the point where LSM blob can be allocated for LSMs. + * + * Return: Returns 0 on success, error on failure. + */ +int security_bpf_token_create(struct bpf_token *token, union bpf_attr *attr, + const struct path *path) +{ + int rc; + + rc = lsm_bpf_token_alloc(token); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bpf_token_create, token, attr, path); + if (unlikely(rc)) + security_bpf_token_free(token); + return rc; +} + +/** + * security_bpf_token_cmd() - Check if BPF token is allowed to delegate + * requested BPF syscall command + * @token: BPF token object + * @cmd: BPF syscall command requested to be delegated by BPF token + * + * Do a check when the kernel decides whether provided BPF token should allow + * delegation of requested BPF syscall command. + * + * Return: Returns 0 on success, error on failure. + */ +int security_bpf_token_cmd(const struct bpf_token *token, enum bpf_cmd cmd) +{ + return call_int_hook(bpf_token_cmd, token, cmd); +} + +/** + * security_bpf_token_capable() - Check if BPF token is allowed to delegate + * requested BPF-related capability + * @token: BPF token object + * @cap: capabilities requested to be delegated by BPF token + * + * Do a check when the kernel decides whether provided BPF token should allow + * delegation of requested BPF-related capabilities. + * + * Return: Returns 0 on success, error on failure. + */ +int security_bpf_token_capable(const struct bpf_token *token, int cap) { - return call_int_hook(bpf_prog_alloc_security, 0, aux); + return call_int_hook(bpf_token_capable, token, cap); } + +/** + * security_bpf_map_free() - Free a bpf map's LSM blob + * @map: bpf map + * + * Clean up the security information stored inside bpf map. + */ void security_bpf_map_free(struct bpf_map *map) { - call_void_hook(bpf_map_free_security, map); + call_void_hook(bpf_map_free, map); + kfree(map->security); + map->security = NULL; } -void security_bpf_prog_free(struct bpf_prog_aux *aux) + +/** + * security_bpf_prog_free() - Free a BPF program's LSM blob + * @prog: BPF program struct + * + * Clean up the security information stored inside BPF program. + */ +void security_bpf_prog_free(struct bpf_prog *prog) +{ + call_void_hook(bpf_prog_free, prog); + kfree(prog->aux->security); + prog->aux->security = NULL; +} + +/** + * security_bpf_token_free() - Free a BPF token's LSM blob + * @token: BPF token struct + * + * Clean up the security information stored inside BPF token. + */ +void security_bpf_token_free(struct bpf_token *token) { - call_void_hook(bpf_prog_free_security, aux); + call_void_hook(bpf_token_free, token); + kfree(token->security); + token->security = NULL; } #endif /* CONFIG_BPF_SYSCALL */ +/** + * security_locked_down() - Check if a kernel feature is allowed + * @what: requested kernel feature + * + * Determine whether a kernel feature that potentially enables arbitrary code + * execution in kernel space should be permitted. + * + * Return: Returns 0 if permission is granted. + */ int security_locked_down(enum lockdown_reason what) { - return call_int_hook(locked_down, 0, what); + return call_int_hook(locked_down, what); } EXPORT_SYMBOL(security_locked_down); +/** + * security_bdev_alloc() - Allocate a block device LSM blob + * @bdev: block device + * + * Allocate and attach a security structure to @bdev->bd_security. The + * security field is initialized to NULL when the bdev structure is + * allocated. + * + * Return: Return 0 if operation was successful. + */ +int security_bdev_alloc(struct block_device *bdev) +{ + int rc = 0; + + rc = lsm_bdev_alloc(bdev); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bdev_alloc_security, bdev); + if (unlikely(rc)) + security_bdev_free(bdev); + + return rc; +} +EXPORT_SYMBOL(security_bdev_alloc); + +/** + * security_bdev_free() - Free a block device's LSM blob + * @bdev: block device + * + * Deallocate the bdev security structure and set @bdev->bd_security to NULL. + */ +void security_bdev_free(struct block_device *bdev) +{ + if (!bdev->bd_security) + return; + + call_void_hook(bdev_free_security, bdev); + + kfree(bdev->bd_security); + bdev->bd_security = NULL; +} +EXPORT_SYMBOL(security_bdev_free); + +/** + * security_bdev_setintegrity() - Set the device's integrity data + * @bdev: block device + * @type: type of integrity, e.g. hash digest, signature, etc + * @value: the integrity value + * @size: size of the integrity value + * + * Register a verified integrity measurement of a bdev with LSMs. + * LSMs should free the previously saved data if @value is NULL. + * Please note that the new hook should be invoked every time the security + * information is updated to keep these data current. For example, in dm-verity, + * if the mapping table is reloaded and configured to use a different dm-verity + * target with a new roothash and signing information, the previously stored + * data in the LSM blob will become obsolete. It is crucial to re-invoke the + * hook to refresh these data and ensure they are up to date. This necessity + * arises from the design of device-mapper, where a device-mapper device is + * first created, and then targets are subsequently loaded into it. These + * targets can be modified multiple times during the device's lifetime. + * Therefore, while the LSM blob is allocated during the creation of the block + * device, its actual contents are not initialized at this stage and can change + * substantially over time. This includes alterations from data that the LSMs + * 'trusts' to those they do not, making it essential to handle these changes + * correctly. Failure to address this dynamic aspect could potentially allow + * for bypassing LSM checks. + * + * Return: Returns 0 on success, negative values on failure. + */ +int security_bdev_setintegrity(struct block_device *bdev, + enum lsm_integrity_type type, const void *value, + size_t size) +{ + return call_int_hook(bdev_setintegrity, bdev, type, value, size); +} +EXPORT_SYMBOL(security_bdev_setintegrity); + #ifdef CONFIG_PERF_EVENTS -int security_perf_event_open(struct perf_event_attr *attr, int type) +/** + * security_perf_event_open() - Check if a perf event open is allowed + * @type: type of event + * + * Check whether the @type of perf_event_open syscall is allowed. + * + * Return: Returns 0 if permission is granted. + */ +int security_perf_event_open(int type) { - return call_int_hook(perf_event_open, 0, attr, type); + return call_int_hook(perf_event_open, type); } +/** + * security_perf_event_alloc() - Allocate a perf event LSM blob + * @event: perf event + * + * Allocate and save perf_event security info. + * + * Return: Returns 0 on success, error on failure. + */ int security_perf_event_alloc(struct perf_event *event) { - return call_int_hook(perf_event_alloc, 0, event); + int rc; + + rc = lsm_blob_alloc(&event->security, blob_sizes.lbs_perf_event, + GFP_KERNEL); + if (rc) + return rc; + + rc = call_int_hook(perf_event_alloc, event); + if (rc) { + kfree(event->security); + event->security = NULL; + } + return rc; } +/** + * security_perf_event_free() - Free a perf event LSM blob + * @event: perf event + * + * Release (free) perf_event security info. + */ void security_perf_event_free(struct perf_event *event) { - call_void_hook(perf_event_free, event); + kfree(event->security); + event->security = NULL; } +/** + * security_perf_event_read() - Check if reading a perf event label is allowed + * @event: perf event + * + * Read perf_event security info if allowed. + * + * Return: Returns 0 if permission is granted. + */ int security_perf_event_read(struct perf_event *event) { - return call_int_hook(perf_event_read, 0, event); + return call_int_hook(perf_event_read, event); } +/** + * security_perf_event_write() - Check if writing a perf event label is allowed + * @event: perf event + * + * Write perf_event security info if allowed. + * + * Return: Returns 0 if permission is granted. + */ int security_perf_event_write(struct perf_event *event) { - return call_int_hook(perf_event_write, 0, event); + return call_int_hook(perf_event_write, event); } #endif /* CONFIG_PERF_EVENTS */ #ifdef CONFIG_IO_URING +/** + * security_uring_override_creds() - Check if overriding creds is allowed + * @new: new credentials + * + * Check if the current task, executing an io_uring operation, is allowed to + * override it's credentials with @new. + * + * Return: Returns 0 if permission is granted. + */ int security_uring_override_creds(const struct cred *new) { - return call_int_hook(uring_override_creds, 0, new); + return call_int_hook(uring_override_creds, new); } +/** + * security_uring_sqpoll() - Check if IORING_SETUP_SQPOLL is allowed + * + * Check whether the current task is allowed to spawn a io_uring polling thread + * (IORING_SETUP_SQPOLL). + * + * Return: Returns 0 if permission is granted. + */ int security_uring_sqpoll(void) { - return call_int_hook(uring_sqpoll, 0); + return call_int_hook(uring_sqpoll); } + +/** + * security_uring_cmd() - Check if a io_uring passthrough command is allowed + * @ioucmd: command + * + * Check whether the file_operations uring_cmd is allowed to run. + * + * Return: Returns 0 if permission is granted. + */ int security_uring_cmd(struct io_uring_cmd *ioucmd) { - return call_int_hook(uring_cmd, 0, ioucmd); + return call_int_hook(uring_cmd, ioucmd); +} + +/** + * security_uring_allowed() - Check if io_uring_setup() is allowed + * + * Check whether the current task is allowed to call io_uring_setup(). + * + * Return: Returns 0 if permission is granted. + */ +int security_uring_allowed(void) +{ + return call_int_hook(uring_allowed); } #endif /* CONFIG_IO_URING */ + +/** + * security_initramfs_populated() - Notify LSMs that initramfs has been loaded + * + * Tells the LSMs the initramfs has been unpacked into the rootfs. + */ +void security_initramfs_populated(void) +{ + call_void_hook(initramfs_populated); +} |