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-rw-r--r--security/security.c285
1 files changed, 264 insertions, 21 deletions
diff --git a/security/security.c b/security/security.c
index dcb3e7014f9b..0144a98d3712 100644
--- a/security/security.c
+++ b/security/security.c
@@ -35,6 +35,24 @@
#define LSM_COUNT (__end_lsm_info - __start_lsm_info)
/*
+ * How many LSMs are built into the kernel as determined at
+ * build time. Used to determine fixed array sizes.
+ * The capability module is accounted for by CONFIG_SECURITY
+ */
+#define LSM_CONFIG_COUNT ( \
+ (IS_ENABLED(CONFIG_SECURITY) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_TOMOYO) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_YAMA) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_LOADPIN) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0))
+
+/*
* These are descriptions of the reasons that can be passed to the
* security_locked_down() LSM hook. Placing this array here allows
* all security modules to use the same descriptions for auditing
@@ -245,6 +263,12 @@ static void __init initialize_lsm(struct lsm_info *lsm)
}
}
+/*
+ * Current index to use while initializing the lsm id list.
+ */
+u32 lsm_active_cnt __ro_after_init;
+const struct lsm_id *lsm_idlist[LSM_CONFIG_COUNT];
+
/* Populate ordered LSMs list from comma-separated LSM name list. */
static void __init ordered_lsm_parse(const char *order, const char *origin)
{
@@ -513,17 +537,29 @@ static int lsm_append(const char *new, char **result)
* 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
+ * @lsmid: the identification information for the security module
*
* Each LSM has to register its hooks with the infrastructure.
*/
void __init security_add_hooks(struct security_hook_list *hooks, int count,
- const char *lsm)
+ const struct lsm_id *lsmid)
{
int i;
+ /*
+ * A security module may call security_add_hooks() more
+ * than once during initialization, and LSM initialization
+ * is serialized. Landlock is one such case.
+ * Look at the previous entry, if there is one, for duplication.
+ */
+ if (lsm_active_cnt == 0 || lsm_idlist[lsm_active_cnt - 1] != lsmid) {
+ if (lsm_active_cnt >= LSM_CONFIG_COUNT)
+ panic("%s Too many LSMs registered.\n", __func__);
+ lsm_idlist[lsm_active_cnt++] = lsmid;
+ }
+
for (i = 0; i < count; i++) {
- hooks[i].lsm = lsm;
+ hooks[i].lsmid = lsmid;
hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
}
@@ -532,7 +568,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
* and fix this up afterwards.
*/
if (slab_is_available()) {
- if (lsm_append(lsm, &lsm_names) < 0)
+ if (lsm_append(lsmid->name, &lsm_names) < 0)
panic("%s - Cannot get early memory.\n", __func__);
}
}
@@ -734,6 +770,54 @@ static int lsm_superblock_alloc(struct super_block *sb)
return 0;
}
+/**
+ * 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.
+ *
+ * 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, size_t *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;
+ }
+
+ 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;
+}
+
/*
* The default value of the LSM hook is defined in linux/lsm_hook_defs.h and
* can be accessed with:
@@ -2539,7 +2623,7 @@ int security_inode_copy_up_xattr(const char *name)
return rc;
}
- return LSM_RET_DEFAULT(inode_copy_up_xattr);
+ return evm_inode_copy_up_xattr(name);
}
EXPORT_SYMBOL(security_inode_copy_up_xattr);
@@ -2580,13 +2664,7 @@ int security_kernfs_init_security(struct kernfs_node *kn_dir,
*/
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, 0, file, mask);
}
/**
@@ -2648,6 +2726,24 @@ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long 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, 0, file, cmd, arg);
+}
+EXPORT_SYMBOL_GPL(security_file_ioctl_compat);
+
static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
{
/*
@@ -2837,7 +2933,7 @@ int security_file_open(struct file *file)
if (ret)
return ret;
- return fsnotify_perm(file, MAY_OPEN);
+ return fsnotify_open_perm(file);
}
/**
@@ -3800,10 +3896,158 @@ void security_d_instantiate(struct dentry *dentry, struct inode *inode)
}
EXPORT_SYMBOL(security_d_instantiate);
+/*
+ * 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,
+ size_t __user *size, u32 flags)
+{
+ struct security_hook_list *hp;
+ struct lsm_ctx lctx = { .id = LSM_ID_UNDEF, };
+ u8 __user *base = (u8 __user *)uctx;
+ size_t total = 0;
+ size_t entrysize;
+ size_t 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.
+ */
+ hlist_for_each_entry(hp, &security_hook_heads.getselfattr, list) {
+ if (single && lctx.id != hp->lsmid->id)
+ continue;
+ entrysize = left;
+ if (base)
+ uctx = (struct lsm_ctx __user *)(base + total);
+ rc = hp->hook.getselfattr(attr, uctx, &entrysize, flags);
+ if (rc == -EOPNOTSUPP) {
+ rc = 0;
+ 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,
+ size_t size, u32 flags)
+{
+ struct security_hook_list *hp;
+ struct lsm_ctx *lctx;
+ int rc = LSM_RET_DEFAULT(setselfattr);
+
+ 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 || size < lctx->ctx_len + sizeof(*lctx) ||
+ lctx->len < lctx->ctx_len + sizeof(*lctx)) {
+ rc = -EINVAL;
+ goto free_out;
+ }
+
+ hlist_for_each_entry(hp, &security_hook_heads.setselfattr, list)
+ if ((hp->lsmid->id) == lctx->id) {
+ rc = hp->hook.setselfattr(attr, lctx, size, flags);
+ break;
+ }
+
+free_out:
+ kfree(lctx);
+ return rc;
+}
+
/**
* security_getprocattr() - Read an attribute for a task
* @p: the task
- * @lsm: LSM name
+ * @lsmid: LSM identification
* @name: attribute name
* @value: attribute value
*
@@ -3811,13 +4055,13 @@ EXPORT_SYMBOL(security_d_instantiate);
*
* Return: Returns the length of @value on success, a negative value otherwise.
*/
-int security_getprocattr(struct task_struct *p, const char *lsm,
- const char *name, char **value)
+int security_getprocattr(struct task_struct *p, int lsmid, const char *name,
+ char **value)
{
struct security_hook_list *hp;
hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
- if (lsm != NULL && strcmp(lsm, hp->lsm))
+ if (lsmid != 0 && lsmid != hp->lsmid->id)
continue;
return hp->hook.getprocattr(p, name, value);
}
@@ -3826,7 +4070,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm,
/**
* security_setprocattr() - Set an attribute for a task
- * @lsm: LSM name
+ * @lsmid: LSM identification
* @name: attribute name
* @value: attribute value
* @size: attribute value size
@@ -3836,13 +4080,12 @@ int security_getprocattr(struct task_struct *p, const char *lsm,
*
* Return: Returns bytes written on success, a negative value otherwise.
*/
-int security_setprocattr(const char *lsm, const char *name, void *value,
- size_t size)
+int security_setprocattr(int lsmid, const char *name, void *value, size_t size)
{
struct security_hook_list *hp;
hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
- if (lsm != NULL && strcmp(lsm, hp->lsm))
+ if (lsmid != 0 && lsmid != hp->lsmid->id)
continue;
return hp->hook.setprocattr(name, value, size);
}