diff options
Diffstat (limited to 'security/apparmor/domain.c')
| -rw-r--r-- | security/apparmor/domain.c | 662 |
1 files changed, 384 insertions, 278 deletions
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 08c88de0ffda..267da82afb14 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * AppArmor security module * @@ -5,21 +6,16 @@ * * Copyright (C) 2002-2008 Novell/SUSE * Copyright 2009-2010 Canonical Ltd. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation, version 2 of the - * License. */ #include <linux/errno.h> -#include <linux/fdtable.h> +#include <linux/fs.h> #include <linux/file.h> #include <linux/mount.h> #include <linux/syscalls.h> -#include <linux/tracehook.h> #include <linux/personality.h> #include <linux/xattr.h> +#include <linux/user_namespace.h> #include "include/audit.h" #include "include/apparmorfs.h" @@ -32,26 +28,15 @@ #include "include/policy.h" #include "include/policy_ns.h" -/** - * aa_free_domain_entries - free entries in a domain table - * @domain: the domain table to free (MAYBE NULL) - */ -void aa_free_domain_entries(struct aa_domain *domain) -{ - int i; - if (domain) { - if (!domain->table) - return; - - for (i = 0; i < domain->size; i++) - kzfree(domain->table[i]); - kzfree(domain->table); - domain->table = NULL; - } -} +static const char * const CONFLICTING_ATTACH_STR = "conflicting profile attachments"; +static const char * const CONFLICTING_ATTACH_STR_IX = + "conflicting profile attachments - ix fallback"; +static const char * const CONFLICTING_ATTACH_STR_UX = + "conflicting profile attachments - ux fallback"; /** * may_change_ptraced_domain - check if can change profile on ptraced task + * @to_cred: cred of task changing domain * @to_label: profile to change to (NOT NULL) * @info: message if there is an error * @@ -60,28 +45,34 @@ void aa_free_domain_entries(struct aa_domain *domain) * * Returns: %0 or error if change not allowed */ -static int may_change_ptraced_domain(struct aa_label *to_label, +static int may_change_ptraced_domain(const struct cred *to_cred, + struct aa_label *to_label, const char **info) { struct task_struct *tracer; struct aa_label *tracerl = NULL; + const struct cred *tracer_cred = NULL; + int error = 0; rcu_read_lock(); tracer = ptrace_parent(current); - if (tracer) + if (tracer) { /* released below */ tracerl = aa_get_task_label(tracer); - + tracer_cred = get_task_cred(tracer); + } /* not ptraced */ if (!tracer || unconfined(tracerl)) goto out; - error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); + error = aa_may_ptrace(tracer_cred, tracerl, to_cred, to_label, + PTRACE_MODE_ATTACH); out: rcu_read_unlock(); aa_put_label(tracerl); + put_cred(tracer_cred); if (error) *info = "ptrace prevents transition"; @@ -91,30 +82,31 @@ out: /**** TODO: dedup to aa_label_match - needs perm and dfa, merging * specifically this is an exact copy of aa_label_match except * aa_compute_perms is replaced with aa_compute_fperms - * and policy.dfa with file.dfa + * and policy->dfa with file->dfa ****/ /* match a profile and its associated ns component if needed * Assumes visibility test has already been done. * If a subns profile is not to be matched should be prescreened with * visibility test. */ -static inline unsigned int match_component(struct aa_profile *profile, - struct aa_profile *tp, - bool stack, unsigned int state) +static inline aa_state_t match_component(struct aa_profile *profile, + struct aa_profile *tp, + bool stack, aa_state_t state) { + struct aa_ruleset *rules = profile->label.rules[0]; const char *ns_name; if (stack) - state = aa_dfa_match(profile->file.dfa, state, "&"); + state = aa_dfa_match(rules->file->dfa, state, "&"); if (profile->ns == tp->ns) - return aa_dfa_match(profile->file.dfa, state, tp->base.hname); + return aa_dfa_match(rules->file->dfa, state, tp->base.hname); /* try matching with namespace name and then profile */ ns_name = aa_ns_name(profile->ns, tp->ns, true); - state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); - state = aa_dfa_match(profile->file.dfa, state, ns_name); - state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); - return aa_dfa_match(profile->file.dfa, state, tp->base.hname); + state = aa_dfa_match_len(rules->file->dfa, state, ":", 1); + state = aa_dfa_match(rules->file->dfa, state, ns_name); + state = aa_dfa_match_len(rules->file->dfa, state, ":", 1); + return aa_dfa_match(rules->file->dfa, state, tp->base.hname); } /** @@ -122,7 +114,7 @@ static inline unsigned int match_component(struct aa_profile *profile, * @profile: profile to find perms for * @label: label to check access permissions for * @stack: whether this is a stacking request - * @start: state to start match in + * @state: state to start match in * @subns: whether to do permission checks on components in a subns * @request: permissions to request * @perms: perms struct to set @@ -135,9 +127,10 @@ static inline unsigned int match_component(struct aa_profile *profile, */ static int label_compound_match(struct aa_profile *profile, struct aa_label *label, bool stack, - unsigned int state, bool subns, u32 request, + aa_state_t state, bool subns, u32 request, struct aa_perms *perms) { + struct aa_ruleset *rules = profile->label.rules[0]; struct aa_profile *tp; struct label_it i; struct path_cond cond = { }; @@ -160,12 +153,13 @@ next: label_for_each_cont(i, label, tp) { if (!aa_ns_visible(profile->ns, tp->ns, subns)) continue; - state = aa_dfa_match(profile->file.dfa, state, "//&"); + state = aa_dfa_match(rules->file->dfa, state, "//&"); state = match_component(profile, tp, false, state); if (!state) goto fail; } - *perms = aa_compute_fperms(profile->file.dfa, state, &cond); + *perms = *(aa_lookup_condperms(current_fsuid(), rules->file, state, + &cond)); aa_apply_modes_to_perms(profile, perms); if ((perms->allow & request) != request) return -EACCES; @@ -195,14 +189,15 @@ fail: */ static int label_components_match(struct aa_profile *profile, struct aa_label *label, bool stack, - unsigned int start, bool subns, u32 request, + aa_state_t start, bool subns, u32 request, struct aa_perms *perms) { + struct aa_ruleset *rules = profile->label.rules[0]; struct aa_profile *tp; struct label_it i; struct aa_perms tmp; struct path_cond cond = { }; - unsigned int state = 0; + aa_state_t state = 0; /* find first subcomponent to test */ label_for_each(i, label, tp) { @@ -218,7 +213,8 @@ static int label_components_match(struct aa_profile *profile, return 0; next: - tmp = aa_compute_fperms(profile->file.dfa, state, &cond); + tmp = *(aa_lookup_condperms(current_fsuid(), rules->file, state, + &cond)); aa_apply_modes_to_perms(profile, &tmp); aa_perms_accum(perms, &tmp); label_for_each_cont(i, label, tp) { @@ -227,7 +223,8 @@ next: state = match_component(profile, tp, stack, start); if (!state) goto fail; - tmp = aa_compute_fperms(profile->file.dfa, state, &cond); + tmp = *(aa_lookup_condperms(current_fsuid(), rules->file, state, + &cond)); aa_apply_modes_to_perms(profile, &tmp); aa_perms_accum(perms, &tmp); } @@ -255,7 +252,7 @@ fail: * Returns: the state the match finished in, may be the none matching state */ static int label_match(struct aa_profile *profile, struct aa_label *label, - bool stack, unsigned int state, bool subns, u32 request, + bool stack, aa_state_t state, bool subns, u32 request, struct aa_perms *perms) { int error; @@ -280,6 +277,7 @@ static int label_match(struct aa_profile *profile, struct aa_label *label, * @stack: whether this is a stacking request * @request: requested perms * @start: state to start matching in + * @perms: Returns computed perms (NOT NULL) * * * Returns: permission set @@ -289,7 +287,7 @@ static int label_match(struct aa_profile *profile, struct aa_label *label, */ static int change_profile_perms(struct aa_profile *profile, struct aa_label *target, bool stack, - u32 request, unsigned int start, + u32 request, aa_state_t start, struct aa_perms *perms) { if (profile_unconfined(profile)) { @@ -311,39 +309,46 @@ static int change_profile_perms(struct aa_profile *profile, * Returns: number of extended attributes that matched, or < 0 on error */ static int aa_xattrs_match(const struct linux_binprm *bprm, - struct aa_profile *profile, unsigned int state) + struct aa_profile *profile, aa_state_t state) { int i; - ssize_t size; struct dentry *d; char *value = NULL; - int value_size = 0, ret = profile->xattr_count; + struct aa_attachment *attach = &profile->attach; + int size, value_size = 0, ret = attach->xattr_count; - if (!bprm || !profile->xattr_count) + if (!bprm || !attach->xattr_count) return 0; + might_sleep(); /* transition from exec match to xattr set */ - state = aa_dfa_null_transition(profile->xmatch, state); - + state = aa_dfa_outofband_transition(attach->xmatch->dfa, state); d = bprm->file->f_path.dentry; - for (i = 0; i < profile->xattr_count; i++) { - size = vfs_getxattr_alloc(d, profile->xattrs[i], &value, - value_size, GFP_KERNEL); + for (i = 0; i < attach->xattr_count; i++) { + size = vfs_getxattr_alloc(&nop_mnt_idmap, d, attach->xattrs[i], + &value, value_size, GFP_KERNEL); if (size >= 0) { - u32 perm; + struct aa_perms *perms; - /* Check the xattr value, not just presence */ - state = aa_dfa_match_len(profile->xmatch, state, value, - size); - perm = dfa_user_allow(profile->xmatch, state); - if (!(perm & MAY_EXEC)) { + /* + * Check the xattr presence before value. This ensure + * that not present xattr can be distinguished from a 0 + * length value or rule that matches any value + */ + state = aa_dfa_null_transition(attach->xmatch->dfa, + state); + /* Check xattr value */ + state = aa_dfa_match_len(attach->xmatch->dfa, state, + value, size); + perms = aa_lookup_perms(attach->xmatch, state); + if (!(perms->allow & MAY_EXEC)) { ret = -EINVAL; goto out; } } /* transition to next element */ - state = aa_dfa_null_transition(profile->xmatch, state); + state = aa_dfa_outofband_transition(attach->xmatch->dfa, state); if (size < 0) { /* * No xattr match, so verify if transition to @@ -365,11 +370,12 @@ out: } /** - * __attach_match_ - find an attachment match - * @bprm - binprm structure of transitioning task - * @name - to match against (NOT NULL) - * @head - profile list to walk (NOT NULL) - * @info - info message if there was an error (NOT NULL) + * find_attach - do attachment search for unconfined processes + * @bprm: binprm structure of transitioning task + * @ns: the current namespace (NOT NULL) + * @head: profile list to walk (NOT NULL) + * @name: to match against (NOT NULL) + * @info: info message if there was an error (NOT NULL) * * Do a linear search on the profiles in the list. There is a matching * preference where an exact match is preferred over a name which uses @@ -378,12 +384,11 @@ out: * * Requires: @head not be shared or have appropriate locks held * - * Returns: profile or NULL if no match found + * Returns: label or NULL if no match found */ -static struct aa_profile *__attach_match(const struct linux_binprm *bprm, - const char *name, - struct list_head *head, - const char **info) +static struct aa_label *find_attach(const struct linux_binprm *bprm, + struct aa_ns *ns, struct list_head *head, + const char *name, const char **info) { int candidate_len = 0, candidate_xattrs = 0; bool conflict = false; @@ -392,7 +397,11 @@ static struct aa_profile *__attach_match(const struct linux_binprm *bprm, AA_BUG(!name); AA_BUG(!head); + rcu_read_lock(); +restart: list_for_each_entry_rcu(profile, head, base.list) { + struct aa_attachment *attach = &profile->attach; + if (profile->label.flags & FLAG_NULL && &profile->label == ns_unconfined(profile->ns)) continue; @@ -408,25 +417,43 @@ static struct aa_profile *__attach_match(const struct linux_binprm *bprm, * as another profile, signal a conflict and refuse to * match. */ - if (profile->xmatch) { - unsigned int state, count; - u32 perm; - - state = aa_dfa_leftmatch(profile->xmatch, DFA_START, - name, &count); - perm = dfa_user_allow(profile->xmatch, state); + if (attach->xmatch->dfa) { + unsigned int count; + aa_state_t state; + struct aa_perms *perms; + + state = aa_dfa_leftmatch(attach->xmatch->dfa, + attach->xmatch->start[AA_CLASS_XMATCH], + name, &count); + perms = aa_lookup_perms(attach->xmatch, state); /* any accepting state means a valid match. */ - if (perm & MAY_EXEC) { - int ret; + if (perms->allow & MAY_EXEC) { + int ret = 0; if (count < candidate_len) continue; - ret = aa_xattrs_match(bprm, profile, state); - /* Fail matching if the xattrs don't match */ - if (ret < 0) - continue; - + if (bprm && attach->xattr_count) { + long rev = READ_ONCE(ns->revision); + + if (!aa_get_profile_not0(profile)) + goto restart; + rcu_read_unlock(); + ret = aa_xattrs_match(bprm, profile, + state); + rcu_read_lock(); + aa_put_profile(profile); + if (rev != + READ_ONCE(ns->revision)) + /* policy changed */ + goto restart; + /* + * Fail matching if the xattrs don't + * match + */ + if (ret < 0) + continue; + } /* * TODO: allow for more flexible best match * @@ -445,47 +472,32 @@ static struct aa_profile *__attach_match(const struct linux_binprm *bprm, * xattrs, or a longer match */ candidate = profile; - candidate_len = profile->xmatch_len; + candidate_len = max(count, attach->xmatch_len); candidate_xattrs = ret; conflict = false; } - } else if (!strcmp(profile->base.name, name)) + } else if (!strcmp(profile->base.name, name)) { /* * old exact non-re match, without conditionals such * as xattrs. no more searching required */ - return profile; + candidate = profile; + goto out; + } } - if (conflict) { - *info = "conflicting profile attachments"; + if (!candidate || conflict) { + if (conflict) + *info = CONFLICTING_ATTACH_STR; + rcu_read_unlock(); return NULL; } - return candidate; -} - -/** - * find_attach - do attachment search for unconfined processes - * @bprm - binprm structure of transitioning task - * @ns: the current namespace (NOT NULL) - * @list: list to search (NOT NULL) - * @name: the executable name to match against (NOT NULL) - * @info: info message if there was an error - * - * Returns: label or NULL if no match found - */ -static struct aa_label *find_attach(const struct linux_binprm *bprm, - struct aa_ns *ns, struct list_head *list, - const char *name, const char **info) -{ - struct aa_profile *profile; - - rcu_read_lock(); - profile = aa_get_profile(__attach_match(bprm, name, list, info)); +out: + candidate = aa_get_newest_profile(candidate); rcu_read_unlock(); - return profile ? &profile->label : NULL; + return &candidate->label; } static const char *next_name(int xtype, const char *name) @@ -500,13 +512,16 @@ static const char *next_name(int xtype, const char *name) * @name: returns: name tested to find label (NOT NULL) * * Returns: refcounted label, or NULL on failure (MAYBE NULL) + * @name will always be set with the last name tried */ struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, const char **name) { + struct aa_ruleset *rules = profile->label.rules[0]; struct aa_label *label = NULL; u32 xtype = xindex & AA_X_TYPE_MASK; int index = xindex & AA_X_INDEX_MASK; + const char *next; AA_BUG(!name); @@ -514,25 +529,27 @@ struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, /* TODO: move lookup parsing to unpack time so this is a straight * index into the resultant label */ - for (*name = profile->file.trans.table[index]; !label && *name; - *name = next_name(xtype, *name)) { + for (next = rules->file->trans.table[index]; next; + next = next_name(xtype, next)) { + const char *lookup = (*next == '&') ? next + 1 : next; + *name = next; if (xindex & AA_X_CHILD) { - struct aa_profile *new_profile; - /* release by caller */ - new_profile = aa_find_child(profile, *name); - if (new_profile) - label = &new_profile->label; + /* TODO: switich to parse to get stack of child */ + struct aa_profile *new = aa_find_child(profile, lookup); + + if (new) + /* release by caller */ + return &new->label; continue; } - label = aa_label_parse(&profile->label, *name, GFP_ATOMIC, + label = aa_label_parse(&profile->label, lookup, GFP_KERNEL, true, false); - if (IS_ERR(label)) - label = NULL; + if (!IS_ERR_OR_NULL(label)) + /* release by caller */ + return label; } - /* released by caller */ - - return label; + return NULL; } /** @@ -542,6 +559,7 @@ struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, * @name: name to lookup (NOT NULL) * @xindex: index into x transition table * @lookupname: returns: name used in lookup if one was specified (NOT NULL) + * @info: info message if there was an error (NOT NULL) * * find label for a transition index * @@ -554,9 +572,11 @@ static struct aa_label *x_to_label(struct aa_profile *profile, const char **info) { struct aa_label *new = NULL; + struct aa_label *stack = NULL; struct aa_ns *ns = profile->ns; u32 xtype = xindex & AA_X_TYPE_MASK; - const char *stack = NULL; + /* Used for info checks during fallback handling */ + const char *old_info = NULL; switch (xtype) { case AA_X_NONE: @@ -565,14 +585,15 @@ static struct aa_label *x_to_label(struct aa_profile *profile, break; case AA_X_TABLE: /* TODO: fix when perm mapping done at unload */ - stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; - if (*stack != '&') { - /* released by caller */ - new = x_table_lookup(profile, xindex, lookupname); - stack = NULL; + /* released by caller + * if null for both stack and direct want to try fallback + */ + new = x_table_lookup(profile, xindex, lookupname); + if (!new || **lookupname != '&') break; - } - /* fall through to X_NAME */ + stack = new; + new = NULL; + fallthrough; /* to X_NAME */ case AA_X_NAME: if (xindex & AA_X_CHILD) /* released by caller */ @@ -586,17 +607,38 @@ static struct aa_label *x_to_label(struct aa_profile *profile, break; } + /* fallback transition check */ if (!new) { if (xindex & AA_X_INHERIT) { /* (p|c|n)ix - don't change profile but do * use the newest version */ - *info = "ix fallback"; + if (*info == CONFLICTING_ATTACH_STR) { + *info = CONFLICTING_ATTACH_STR_IX; + } else { + old_info = *info; + *info = "ix fallback"; + } /* no profile && no error */ new = aa_get_newest_label(&profile->label); } else if (xindex & AA_X_UNCONFINED) { new = aa_get_newest_label(ns_unconfined(profile->ns)); - *info = "ux fallback"; + if (*info == CONFLICTING_ATTACH_STR) { + *info = CONFLICTING_ATTACH_STR_UX; + } else { + old_info = *info; + *info = "ux fallback"; + } + } + /* We set old_info on the code paths above where overwriting + * could have happened, so now check if info was set by + * find_attach as well (i.e. whether we actually overwrote) + * and warn accordingly. + */ + if (old_info && old_info != CONFLICTING_ATTACH_STR) { + pr_warn_ratelimited( + "AppArmor: find_attach (from profile %s) audit info \"%s\" dropped", + profile->base.hname, old_info); } } @@ -604,26 +646,27 @@ static struct aa_label *x_to_label(struct aa_profile *profile, /* base the stack on post domain transition */ struct aa_label *base = new; - new = aa_label_parse(base, stack, GFP_ATOMIC, true, false); - if (IS_ERR(new)) - new = NULL; + new = aa_label_merge(base, stack, GFP_KERNEL); + /* null on error */ aa_put_label(base); } + aa_put_label(stack); /* released by caller */ return new; } -static struct aa_label *profile_transition(struct aa_profile *profile, +static struct aa_label *profile_transition(const struct cred *subj_cred, + struct aa_profile *profile, const struct linux_binprm *bprm, char *buffer, struct path_cond *cond, bool *secure_exec) { + struct aa_ruleset *rules = profile->label.rules[0]; struct aa_label *new = NULL; - struct aa_profile *component; - struct label_it i; + struct aa_profile *new_profile = NULL; const char *info = NULL, *name = NULL, *target = NULL; - unsigned int state = profile->file.start; + aa_state_t state = rules->file->start[AA_CLASS_FILE]; struct aa_perms perms = {}; bool nonewprivs = false; int error = 0; @@ -637,7 +680,7 @@ static struct aa_label *profile_transition(struct aa_profile *profile, if (error) { if (profile_unconfined(profile) || (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { - AA_DEBUG("name lookup ix on error"); + AA_DEBUG(DEBUG_DOMAIN, "name lookup ix on error"); error = 0; new = aa_get_newest_label(&profile->label); } @@ -648,61 +691,66 @@ static struct aa_label *profile_transition(struct aa_profile *profile, if (profile_unconfined(profile)) { new = find_attach(bprm, profile->ns, &profile->ns->base.profiles, name, &info); + /* info set -> something unusual that we should report + * Currently this is only conflicting attachments, but other + * infos added in the future should also be logged by default + * and only excluded on a case-by-case basis + */ + if (info) { + /* Because perms is never used again after this audit + * we don't need to care about clobbering it + */ + perms.audit |= MAY_EXEC; + perms.allow |= MAY_EXEC; + /* Don't cause error if auditing fails */ + (void) aa_audit_file(subj_cred, profile, &perms, + OP_EXEC, MAY_EXEC, name, target, new, cond->uid, + info, error); + } if (new) { - AA_DEBUG("unconfined attached to new label"); + AA_DEBUG(DEBUG_DOMAIN, "unconfined attached to new label"); return new; } - AA_DEBUG("unconfined exec no attachment"); + AA_DEBUG(DEBUG_DOMAIN, "unconfined exec no attachment"); return aa_get_newest_label(&profile->label); } /* find exec permissions for name */ - state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); + state = aa_str_perms(rules->file, state, name, cond, &perms); if (perms.allow & MAY_EXEC) { /* exec permission determine how to transition */ new = x_to_label(profile, bprm, name, perms.xindex, &target, &info); if (new && new->proxy == profile->label.proxy && info) { + /* Force audit on conflicting attachment fallback + * Because perms is never used again after this audit + * we don't need to care about clobbering it + */ + if (info == CONFLICTING_ATTACH_STR_IX + || info == CONFLICTING_ATTACH_STR_UX) + perms.audit |= MAY_EXEC; /* hack ix fallback - improve how this is detected */ goto audit; } else if (!new) { - error = -EACCES; + if (info) { + pr_warn_ratelimited( + "AppArmor: %s (from profile %s) audit info \"%s\" dropped on missing transition", + __func__, profile->base.hname, info); + } info = "profile transition not found"; - /* remove MAY_EXEC to audit as failure */ + /* remove MAY_EXEC to audit as failure or complaint */ perms.allow &= ~MAY_EXEC; - } else { - /* verify that each component's xattr requirements are - * met, and fail execution otherwise - */ - label_for_each(i, new, component) { - if (aa_xattrs_match(bprm, component, state) < - 0) { - error = -EACCES; - info = "required xattrs not present"; - perms.allow &= ~MAY_EXEC; - aa_put_label(new); - new = NULL; - goto audit; - } + if (COMPLAIN_MODE(profile)) { + /* create null profile instead of failing */ + goto create_learning_profile; } + error = -EACCES; } } else if (COMPLAIN_MODE(profile)) { +create_learning_profile: /* no exec permission - learning mode */ - struct aa_profile *new_profile = NULL; - char *n = kstrdup(name, GFP_ATOMIC); - - if (n) { - /* name is ptr into buffer */ - long pos = name - buffer; - /* break per cpu buffer hold */ - put_buffers(buffer); - new_profile = aa_new_null_profile(profile, false, n, - GFP_KERNEL); - get_buffers(buffer); - name = buffer + pos; - strcpy((char *)name, n); - kfree(n); - } + new_profile = aa_new_learning_profile(profile, false, name, + GFP_KERNEL); if (!new_profile) { error = -ENOMEM; info = "could not create null profile"; @@ -721,16 +769,17 @@ static struct aa_label *profile_transition(struct aa_profile *profile, if (!(perms.xindex & AA_X_UNSAFE)) { if (DEBUG_ON) { - dbg_printk("apparmor: scrubbing environment variables" - " for %s profile=", name); - aa_label_printk(new, GFP_ATOMIC); + dbg_printk("apparmor: setting AT_SECURE for %s profile=", + name); + aa_label_printk(new, GFP_KERNEL); dbg_printk("\n"); } *secure_exec = true; } audit: - aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, + aa_audit_file(subj_cred, profile, &perms, OP_EXEC, MAY_EXEC, name, + target, new, cond->uid, info, error); if (!new || nonewprivs) { aa_put_label(new); @@ -740,12 +789,14 @@ audit: return new; } -static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, +static int profile_onexec(const struct cred *subj_cred, + struct aa_profile *profile, struct aa_label *onexec, bool stack, const struct linux_binprm *bprm, char *buffer, struct path_cond *cond, bool *secure_exec) { - unsigned int state = profile->file.start; + struct aa_ruleset *rules = profile->label.rules[0]; + aa_state_t state = rules->file->start[AA_CLASS_FILE]; struct aa_perms perms = {}; const char *xname = NULL, *info = "change_profile onexec"; int error = -EACCES; @@ -759,7 +810,7 @@ static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, /* change_profile on exec already granted */ /* * NOTE: Domain transitions from unconfined are allowed - * even when no_new_privs is set because this aways results + * even when no_new_privs is set because this always results * in a further reduction of permissions. */ return 0; @@ -770,7 +821,7 @@ static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, if (error) { if (profile_unconfined(profile) || (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { - AA_DEBUG("name lookup ix on error"); + AA_DEBUG(DEBUG_DOMAIN, "name lookup ix on error"); error = 0; } xname = bprm->filename; @@ -778,7 +829,7 @@ static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, } /* find exec permissions for name */ - state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); + state = aa_str_perms(rules->file, state, xname, cond, &perms); if (!(perms.allow & AA_MAY_ONEXEC)) { info = "no change_onexec valid for executable"; goto audit; @@ -787,7 +838,7 @@ static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, * onexec permission is linked to exec with a standard pairing * exec\0change_profile */ - state = aa_dfa_null_transition(profile->file.dfa, state); + state = aa_dfa_null_transition(rules->file->dfa, state); error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, state, &perms); if (error) { @@ -797,22 +848,24 @@ static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, if (!(perms.xindex & AA_X_UNSAFE)) { if (DEBUG_ON) { - dbg_printk("apparmor: scrubbing environment " - "variables for %s label=", xname); - aa_label_printk(onexec, GFP_ATOMIC); + dbg_printk("apparmor: setting AT_SECURE for %s label=", + xname); + aa_label_printk(onexec, GFP_KERNEL); dbg_printk("\n"); } *secure_exec = true; } audit: - return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, + return aa_audit_file(subj_cred, profile, &perms, OP_EXEC, + AA_MAY_ONEXEC, xname, NULL, onexec, cond->uid, info, error); } /* ensure none ns domain transitions are correctly applied with onexec */ -static struct aa_label *handle_onexec(struct aa_label *label, +static struct aa_label *handle_onexec(const struct cred *subj_cred, + struct aa_label *label, struct aa_label *onexec, bool stack, const struct linux_binprm *bprm, char *buffer, struct path_cond *cond, @@ -827,37 +880,26 @@ static struct aa_label *handle_onexec(struct aa_label *label, AA_BUG(!bprm); AA_BUG(!buffer); - if (!stack) { - error = fn_for_each_in_ns(label, profile, - profile_onexec(profile, onexec, stack, - bprm, buffer, cond, unsafe)); - if (error) - return ERR_PTR(error); - new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, - aa_get_newest_label(onexec), - profile_transition(profile, bprm, buffer, - cond, unsafe)); - - } else { - /* TODO: determine how much we want to loosen this */ - error = fn_for_each_in_ns(label, profile, - profile_onexec(profile, onexec, stack, bprm, - buffer, cond, unsafe)); - if (error) - return ERR_PTR(error); - new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, - aa_label_merge(&profile->label, onexec, - GFP_ATOMIC), - profile_transition(profile, bprm, buffer, - cond, unsafe)); - } + /* TODO: determine how much we want to loosen this */ + error = fn_for_each_in_ns(label, profile, + profile_onexec(subj_cred, profile, onexec, stack, + bprm, buffer, cond, unsafe)); + if (error) + return ERR_PTR(error); + new = fn_label_build_in_ns(label, profile, GFP_KERNEL, + stack ? aa_label_merge(&profile->label, onexec, + GFP_KERNEL) + : aa_get_newest_label(onexec), + profile_transition(subj_cred, profile, bprm, + buffer, cond, unsafe)); if (new) return new; /* TODO: get rid of GLOBAL_ROOT_UID */ error = fn_for_each_in_ns(label, profile, - aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, + aa_audit_file(subj_cred, profile, &nullperms, + OP_CHANGE_ONEXEC, AA_MAY_ONEXEC, bprm->filename, NULL, onexec, GLOBAL_ROOT_UID, "failed to build target label", -ENOMEM)); @@ -865,30 +907,31 @@ static struct aa_label *handle_onexec(struct aa_label *label, } /** - * apparmor_bprm_set_creds - set the new creds on the bprm struct + * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct * @bprm: binprm for the exec (NOT NULL) * * Returns: %0 or error on failure * * TODO: once the other paths are done see if we can't refactor into a fn */ -int apparmor_bprm_set_creds(struct linux_binprm *bprm) +int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm) { struct aa_task_ctx *ctx; struct aa_label *label, *new = NULL; + const struct cred *subj_cred; struct aa_profile *profile; char *buffer = NULL; const char *info = NULL; int error = 0; bool unsafe = false; + vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(bprm->file), + file_inode(bprm->file)); struct path_cond cond = { - file_inode(bprm->file)->i_uid, + vfsuid_into_kuid(vfsuid), file_inode(bprm->file)->i_mode }; - if (bprm->called_set_creds) - return 0; - + subj_cred = current_cred(); ctx = task_ctx(current); AA_BUG(!cred_label(bprm->cred)); AA_BUG(!ctx); @@ -907,14 +950,20 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) ctx->nnp = aa_get_label(label); /* buffer freed below, name is pointer into buffer */ - get_buffers(buffer); + buffer = aa_get_buffer(false); + if (!buffer) { + error = -ENOMEM; + goto done; + } + /* Test for onexec first as onexec override other x transitions. */ if (ctx->onexec) - new = handle_onexec(label, ctx->onexec, ctx->token, + new = handle_onexec(subj_cred, label, ctx->onexec, ctx->token, bprm, buffer, &cond, &unsafe); else - new = fn_label_build(label, profile, GFP_ATOMIC, - profile_transition(profile, bprm, buffer, + new = fn_label_build(label, profile, GFP_KERNEL, + profile_transition(subj_cred, profile, bprm, + buffer, &cond, &unsafe)); AA_BUG(!new); @@ -932,10 +981,11 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) * * NOTE: Domain transitions from unconfined and to stacked * subsets are allowed even when no_new_privs is set because this - * aways results in a further reduction of permissions. + * always results in a further reduction of permissions. */ if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && - !unconfined(label) && !aa_label_is_subset(new, ctx->nnp)) { + !unconfined(label) && + !aa_label_is_unconfined_subset(new, ctx->nnp)) { error = -EPERM; info = "no new privs"; goto audit; @@ -948,16 +998,16 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { /* TODO: test needs to be profile of label to new */ - error = may_change_ptraced_domain(new, &info); + error = may_change_ptraced_domain(bprm->cred, new, &info); if (error) goto audit; } if (unsafe) { if (DEBUG_ON) { - dbg_printk("scrubbing environment variables for %s " - "label=", bprm->filename); - aa_label_printk(new, GFP_ATOMIC); + dbg_printk("setting AT_SECURE for %s label=", + bprm->filename); + aa_label_printk(new, GFP_KERNEL); dbg_printk("\n"); } bprm->secureexec = 1; @@ -966,29 +1016,29 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) if (label->proxy != new->proxy) { /* when transitioning clear unsafe personality bits */ if (DEBUG_ON) { - dbg_printk("apparmor: clearing unsafe personality " - "bits. %s label=", bprm->filename); - aa_label_printk(new, GFP_ATOMIC); + dbg_printk("apparmor: clearing unsafe personality bits. %s label=", + bprm->filename); + aa_label_printk(new, GFP_KERNEL); dbg_printk("\n"); } bprm->per_clear |= PER_CLEAR_ON_SETID; } aa_put_label(cred_label(bprm->cred)); /* transfer reference, released when cred is freed */ - cred_label(bprm->cred) = new; + set_cred_label(bprm->cred, new); done: aa_put_label(label); - put_buffers(buffer); + aa_put_buffer(buffer); return error; audit: error = fn_for_each(label, profile, - aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, + aa_audit_file(current_cred(), profile, &nullperms, + OP_EXEC, MAY_EXEC, bprm->filename, NULL, new, - file_inode(bprm->file)->i_uid, info, - error)); + vfsuid_into_kuid(vfsuid), info, error)); aa_put_label(new); goto done; } @@ -1002,7 +1052,8 @@ audit: * * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL */ -static struct aa_label *build_change_hat(struct aa_profile *profile, +static struct aa_label *build_change_hat(const struct cred *subj_cred, + struct aa_profile *profile, const char *name, bool sibling) { struct aa_profile *root, *hat = NULL; @@ -1023,8 +1074,8 @@ static struct aa_label *build_change_hat(struct aa_profile *profile, if (!hat) { error = -ENOENT; if (COMPLAIN_MODE(profile)) { - hat = aa_new_null_profile(profile, true, name, - GFP_KERNEL); + hat = aa_new_learning_profile(profile, true, name, + GFP_KERNEL); if (!hat) { info = "failed null profile create"; error = -ENOMEM; @@ -1034,7 +1085,8 @@ static struct aa_label *build_change_hat(struct aa_profile *profile, aa_put_profile(root); audit: - aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, + aa_audit_file(subj_cred, profile, &nullperms, OP_CHANGE_HAT, + AA_MAY_CHANGEHAT, name, hat ? hat->base.hname : NULL, hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, error); @@ -1050,7 +1102,8 @@ audit: * * Returns: label for hat transition or ERR_PTR. Does not return NULL */ -static struct aa_label *change_hat(struct aa_label *label, const char *hats[], +static struct aa_label *change_hat(const struct cred *subj_cred, + struct aa_label *label, const char *hats[], int count, int flags) { struct aa_profile *profile, *root, *hat = NULL; @@ -1126,7 +1179,8 @@ fail: */ /* TODO: get rid of GLOBAL_ROOT_UID */ if (count > 1 || COMPLAIN_MODE(profile)) { - aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, + aa_audit_file(subj_cred, profile, &nullperms, + OP_CHANGE_HAT, AA_MAY_CHANGEHAT, name, NULL, NULL, GLOBAL_ROOT_UID, info, error); } @@ -1135,7 +1189,8 @@ fail: build: new = fn_label_build_in_ns(label, profile, GFP_KERNEL, - build_change_hat(profile, name, sibling), + build_change_hat(subj_cred, profile, name, + sibling), aa_get_label(&profile->label)); if (!new) { info = "label build failed"; @@ -1165,7 +1220,7 @@ build: */ int aa_change_hat(const char *hats[], int count, u64 token, int flags) { - const struct cred *cred; + const struct cred *subj_cred; struct aa_task_ctx *ctx = task_ctx(current); struct aa_label *label, *previous, *new = NULL, *target = NULL; struct aa_profile *profile; @@ -1174,8 +1229,8 @@ int aa_change_hat(const char *hats[], int count, u64 token, int flags) int error = 0; /* released below */ - cred = get_current_cred(); - label = aa_get_newest_cred_label(cred); + subj_cred = get_current_cred(); + label = aa_get_newest_cred_label(subj_cred); previous = aa_get_newest_label(ctx->previous); /* @@ -1188,14 +1243,28 @@ int aa_change_hat(const char *hats[], int count, u64 token, int flags) if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) ctx->nnp = aa_get_label(label); + /* return -EPERM when unconfined doesn't have children to avoid + * changing the traditional error code for unconfined. + */ if (unconfined(label)) { - info = "unconfined can not change_hat"; - error = -EPERM; - goto fail; + struct label_it i; + bool empty = true; + + rcu_read_lock(); + label_for_each_in_ns(i, labels_ns(label), label, profile) { + empty &= list_empty(&profile->base.profiles); + } + rcu_read_unlock(); + + if (empty) { + info = "unconfined can not change_hat"; + error = -EPERM; + goto fail; + } } if (count) { - new = change_hat(label, hats, count, flags); + new = change_hat(subj_cred, label, hats, count, flags); AA_BUG(!new); if (IS_ERR(new)) { error = PTR_ERR(new); @@ -1204,7 +1273,8 @@ int aa_change_hat(const char *hats[], int count, u64 token, int flags) goto out; } - error = may_change_ptraced_domain(new, &info); + /* target cred is the same as current except new label */ + error = may_change_ptraced_domain(subj_cred, new, &info); if (error) goto fail; @@ -1213,9 +1283,10 @@ int aa_change_hat(const char *hats[], int count, u64 token, int flags) * reduce restrictions. */ if (task_no_new_privs(current) && !unconfined(label) && - !aa_label_is_subset(new, ctx->nnp)) { + !aa_label_is_unconfined_subset(new, ctx->nnp)) { /* not an apparmor denial per se, so don't log it */ - AA_DEBUG("no_new_privs - change_hat denied"); + AA_DEBUG(DEBUG_DOMAIN, + "no_new_privs - change_hat denied"); error = -EPERM; goto out; } @@ -1234,9 +1305,10 @@ int aa_change_hat(const char *hats[], int count, u64 token, int flags) * reduce restrictions. */ if (task_no_new_privs(current) && !unconfined(label) && - !aa_label_is_subset(previous, ctx->nnp)) { + !aa_label_is_unconfined_subset(previous, ctx->nnp)) { /* not an apparmor denial per se, so don't log it */ - AA_DEBUG("no_new_privs - change_hat denied"); + AA_DEBUG(DEBUG_DOMAIN, + "no_new_privs - change_hat denied"); error = -EPERM; goto out; } @@ -1257,7 +1329,7 @@ out: aa_put_label(new); aa_put_label(previous); aa_put_label(label); - put_cred(cred); + put_cred(subj_cred); return error; @@ -1267,7 +1339,7 @@ kill: fail: fn_for_each_in_ns(label, profile, - aa_audit_file(profile, &perms, OP_CHANGE_HAT, + aa_audit_file(subj_cred, profile, &perms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, NULL, NULL, target, GLOBAL_ROOT_UID, info, error)); @@ -1276,28 +1348,33 @@ fail: static int change_profile_perms_wrapper(const char *op, const char *name, + const struct cred *subj_cred, struct aa_profile *profile, struct aa_label *target, bool stack, u32 request, struct aa_perms *perms) { + struct aa_ruleset *rules = profile->label.rules[0]; const char *info = NULL; int error = 0; if (!error) error = change_profile_perms(profile, target, stack, request, - profile->file.start, perms); + rules->file->start[AA_CLASS_FILE], + perms); if (error) - error = aa_audit_file(profile, perms, op, request, name, + error = aa_audit_file(subj_cred, profile, perms, op, request, + name, NULL, target, GLOBAL_ROOT_UID, info, error); return error; } +static const char *stack_msg = "change_profile unprivileged unconfined converted to stacking"; + /** * aa_change_profile - perform a one-way profile transition * @fqname: name of profile may include namespace (NOT NULL) - * @onexec: whether this transition is to take place immediately or at exec * @flags: flags affecting change behavior * * Change to new profile @name. Unlike with hats, there is no way @@ -1317,6 +1394,7 @@ int aa_change_profile(const char *fqname, int flags) const char *auditname = fqname; /* retain leading & if stack */ bool stack = flags & AA_CHANGE_STACK; struct aa_task_ctx *ctx = task_ctx(current); + const struct cred *subj_cred = get_current_cred(); int error = 0; char *op; u32 request; @@ -1334,7 +1412,8 @@ int aa_change_profile(const char *fqname, int flags) ctx->nnp = aa_get_label(label); if (!fqname || !*fqname) { - AA_DEBUG("no profile name"); + aa_put_label(label); + AA_DEBUG(DEBUG_DOMAIN, "no profile name"); return -EINVAL; } @@ -1352,7 +1431,27 @@ int aa_change_profile(const char *fqname, int flags) op = OP_CHANGE_PROFILE; } - label = aa_get_current_label(); + /* This should move to a per profile test. Requires pushing build + * into callback + */ + if (!stack && unconfined(label) && + label == &labels_ns(label)->unconfined->label && + aa_unprivileged_unconfined_restricted && + /* TODO: refactor so this check is a fn */ + cap_capable(current_cred(), &init_user_ns, CAP_MAC_OVERRIDE, + CAP_OPT_NOAUDIT)) { + /* regardless of the request in this case apparmor + * stacks against unconfined so admin set policy can't be + * by-passed + */ + stack = true; + perms.audit = request; + (void) fn_for_each_in_ns(label, profile, + aa_audit_file(subj_cred, profile, &perms, op, + request, auditname, NULL, target, + GLOBAL_ROOT_UID, stack_msg, 0)); + perms.audit = 0; + } if (*fqname == '&') { stack = true; @@ -1374,8 +1473,8 @@ int aa_change_profile(const char *fqname, int flags) !COMPLAIN_MODE(labels_profile(label))) goto audit; /* released below */ - tprofile = aa_new_null_profile(labels_profile(label), false, - fqname, GFP_KERNEL); + tprofile = aa_new_learning_profile(labels_profile(label), false, + fqname, GFP_KERNEL); if (!tprofile) { info = "failed null profile create"; error = -ENOMEM; @@ -1395,6 +1494,7 @@ int aa_change_profile(const char *fqname, int flags) */ error = fn_for_each_in_ns(label, profile, change_profile_perms_wrapper(op, auditname, + subj_cred, profile, target, stack, request, &perms)); if (error) @@ -1405,7 +1505,7 @@ int aa_change_profile(const char *fqname, int flags) check: /* check if tracing task is allowed to trace target domain */ - error = may_change_ptraced_domain(target, &info); + error = may_change_ptraced_domain(subj_cred, target, &info); if (error && !fn_for_each_in_ns(label, profile, COMPLAIN_MODE(profile))) goto audit; @@ -1430,9 +1530,10 @@ check: * reduce restrictions. */ if (task_no_new_privs(current) && !unconfined(label) && - !aa_label_is_subset(new, ctx->nnp)) { + !aa_label_is_unconfined_subset(new, ctx->nnp)) { /* not an apparmor denial per se, so don't log it */ - AA_DEBUG("no_new_privs - change_hat denied"); + AA_DEBUG(DEBUG_DOMAIN, + "no_new_privs - change_hat denied"); error = -EPERM; goto out; } @@ -1444,7 +1545,10 @@ check: new = aa_label_merge(label, target, GFP_KERNEL); if (IS_ERR_OR_NULL(new)) { info = "failed to build target label"; - error = PTR_ERR(new); + if (!new) + error = -ENOMEM; + else + error = PTR_ERR(new); new = NULL; perms.allow = 0; goto audit; @@ -1457,12 +1561,13 @@ check: } /* full transition will be built in exec path */ - error = aa_set_current_onexec(target, stack); + aa_set_current_onexec(target, stack); } audit: error = fn_for_each_in_ns(label, profile, - aa_audit_file(profile, &perms, op, request, auditname, + aa_audit_file(subj_cred, + profile, &perms, op, request, auditname, NULL, new ? new : target, GLOBAL_ROOT_UID, info, error)); @@ -1470,6 +1575,7 @@ out: aa_put_label(new); aa_put_label(target); aa_put_label(label); + put_cred(subj_cred); return error; } |