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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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715281529153015311532153315341535153615371538// SPDX-License-Identifier: GPL-2.0-only/* * AppArmor security module * * This file contains AppArmor policy manipulation functions * * Copyright (C) 1998-2008 Novell/SUSE * Copyright 2009-2010 Canonical Ltd. * * AppArmor policy is based around profiles, which contain the rules a * task is confined by. Every task in the system has a profile attached * to it determined either by matching "unconfined" tasks against the * visible set of profiles or by following a profiles attachment rules. * * Each profile exists in a profile namespace which is a container of * visible profiles. Each namespace contains a special "unconfined" profile, * which doesn't enforce any confinement on a task beyond DAC. * * Namespace and profile names can be written together in either * of two syntaxes. * :namespace:profile - used by kernel interfaces for easy detection * namespace://profile - used by policy * * Profile names can not start with : or @ or ^ and may not contain \0 * * Reserved profile names * unconfined - special automatically generated unconfined profile * inherit - special name to indicate profile inheritance * null-XXXX-YYYY - special automatically generated learning profiles * * Namespace names may not start with / or @ and may not contain \0 or : * Reserved namespace names * user-XXXX - user defined profiles * * a // in a profile or namespace name indicates a hierarchical name with the * name before the // being the parent and the name after the child. * * Profile and namespace hierarchies serve two different but similar purposes. * The namespace contains the set of visible profiles that are considered * for attachment. The hierarchy of namespaces allows for virtualizing * the namespace so that for example a chroot can have its own set of profiles * which may define some local user namespaces. * The profile hierarchy severs two distinct purposes, * - it allows for sub profiles or hats, which allows an application to run * subprograms under its own profile with different restriction than it * self, and not have it use the system profile. * eg. if a mail program starts an editor, the policy might make the * restrictions tighter on the editor tighter than the mail program, * and definitely different than general editor restrictions * - it allows for binary hierarchy of profiles, so that execution history * is preserved. This feature isn't exploited by AppArmor reference policy * but is allowed. NOTE: this is currently suboptimal because profile * aliasing is not currently implemented so that a profile for each * level must be defined. * eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started * from /bin/bash * * A profile or namespace name that can contain one or more // separators * is referred to as an hname (hierarchical). * eg. /bin/bash//bin/ls * * An fqname is a name that may contain both namespace and profile hnames. * eg. :ns:/bin/bash//bin/ls * * NOTES: * - locking of profile lists is currently fairly coarse. All profile * lists within a namespace use the namespace lock. * FIXME: move profile lists to using rcu_lists */
#include <linux/slab.h>#include <linux/spinlock.h>#include <linux/string.h>#include <linux/cred.h>#include <linux/rculist.h>#include <linux/user_namespace.h>
#include "include/apparmor.h"#include "include/capability.h"#include "include/cred.h"#include "include/file.h"#include "include/ipc.h"#include "include/match.h"#include "include/net.h"#include "include/path.h"#include "include/policy.h"#include "include/policy_ns.h"#include "include/policy_unpack.h"#include "include/resource.h"
int unprivileged_userns_apparmor_policy = 1;int aa_unprivileged_unconfined_restricted;
const char *const aa_profile_mode_names[] = { "enforce", "complain", "kill", "unconfined", "user",};
void aa_destroy_tags(struct aa_tags_struct *tags){ kfree_sensitive(tags->hdrs.table); kfree_sensitive(tags->sets.table); aa_destroy_str_table(&tags->strs); memset(tags, 0, sizeof(*tags));}
static void aa_free_pdb(struct aa_policydb *pdb){ if (pdb) { aa_put_dfa(pdb->dfa); kvfree(pdb->perms); aa_destroy_str_table(&pdb->trans); aa_destroy_tags(&pdb->tags); kfree(pdb); }}
/** * aa_pdb_free_kref - free aa_policydb by kref (called by aa_put_pdb) * @kref: kref callback for freeing of a dfa (NOT NULL) */void aa_pdb_free_kref(struct kref *kref){ struct aa_policydb *pdb = container_of(kref, struct aa_policydb, count);
aa_free_pdb(pdb);}
struct aa_policydb *aa_alloc_pdb(gfp_t gfp){ struct aa_policydb *pdb = kzalloc_obj(struct aa_policydb, gfp);
if (!pdb) return NULL;
kref_init(&pdb->count);
return pdb;}
/** * __add_profile - add a profiles to list and label tree * @list: list to add it to (NOT NULL) * @profile: the profile to add (NOT NULL) * * refcount @profile, should be put by __list_remove_profile * * Requires: namespace lock be held, or list not be shared */static void __add_profile(struct list_head *list, struct aa_profile *profile){ struct aa_label *l;
AA_BUG(!list); AA_BUG(!profile); AA_BUG(!profile->ns); AA_BUG(!mutex_is_locked(&profile->ns->lock));
list_add_rcu(&profile->base.list, list); /* get list reference */ aa_get_profile(profile); l = aa_label_insert(&profile->ns->labels, &profile->label); AA_BUG(l != &profile->label); aa_put_label(l);}
/** * __list_remove_profile - remove a profile from the list it is on * @profile: the profile to remove (NOT NULL) * * remove a profile from the list, warning generally removal should * be done with __replace_profile as most profile removals are * replacements to the unconfined profile. * * put @profile list refcount * * Requires: namespace lock be held, or list not have been live */static void __list_remove_profile(struct aa_profile *profile){ AA_BUG(!profile); AA_BUG(!profile->ns); AA_BUG(!mutex_is_locked(&profile->ns->lock));
list_del_rcu(&profile->base.list); aa_put_profile(profile);}
/** * __remove_profile - remove profile, and children * @profile: profile to be removed (NOT NULL) * * Requires: namespace list lock be held, or list not be shared */static void __remove_profile(struct aa_profile *profile){ struct aa_profile *curr, *to_remove;
AA_BUG(!profile); AA_BUG(!profile->ns); AA_BUG(!mutex_is_locked(&profile->ns->lock));
/* release any children lists first */ if (!list_empty(&profile->base.profiles)) { curr = list_first_entry(&profile->base.profiles, struct aa_profile, base.list);
while (curr != profile) {
while (!list_empty(&curr->base.profiles)) curr = list_first_entry(&curr->base.profiles, struct aa_profile, base.list);
to_remove = curr; if (!list_is_last(&to_remove->base.list, &aa_deref_parent(curr)->base.profiles)) curr = list_next_entry(to_remove, base.list); else curr = aa_deref_parent(curr);
/* released by free_profile */ aa_label_remove(&to_remove->label); __aafs_profile_rmdir(to_remove); __list_remove_profile(to_remove); } }
/* released by free_profile */ aa_label_remove(&profile->label); __aafs_profile_rmdir(profile); __list_remove_profile(profile); /* rawdata is only ever referenced by fs lookup, that is no * longer possible here, so put the reference to it. This will * enable the rawdata to be freed if for some reason the profile * is pinned and going to live for a while. */ aa_put_profile_loaddata(profile->rawdata); profile->rawdata = NULL;}
/** * __aa_profile_list_release - remove all profiles on the list and put refs * @head: list of profiles (NOT NULL) * * Requires: namespace lock be held */void __aa_profile_list_release(struct list_head *head){ struct aa_profile *profile, *tmp; list_for_each_entry_safe(profile, tmp, head, base.list) __remove_profile(profile);}
/** * aa_free_data - free a data blob * @ptr: data to free * @arg: unused */static void aa_free_data(void *ptr, void *arg){ struct aa_data *data = ptr;
if (!ptr) return;
kvfree_sensitive(data->data, data->size); kfree_sensitive(data->key); kfree_sensitive(data);}
static void free_attachment(struct aa_attachment *attach){ int i;
if (!attach) return;
for (i = 0; i < attach->xattr_count; i++) kfree_sensitive(attach->xattrs[i]); kfree_sensitive(attach->xattrs); aa_put_pdb(attach->xmatch);}
static void free_ruleset(struct aa_ruleset *rules){ int i;
if (!rules) return;
aa_put_pdb(rules->file); aa_put_pdb(rules->policy); aa_free_cap_rules(&rules->caps); aa_free_rlimit_rules(&rules->rlimits);
for (i = 0; i < rules->secmark_count; i++) kfree_sensitive(rules->secmark[i].label); kfree_sensitive(rules->secmark); kfree_sensitive(rules);}
struct aa_ruleset *aa_alloc_ruleset(gfp_t gfp){ struct aa_ruleset *rules;
rules = kzalloc_obj(*rules, gfp);
return rules;}
/** * aa_free_profile - free a profile * @profile: the profile to free (MAYBE NULL) * * Free a profile, its hats and null_profile. All references to the profile, * its hats and null_profile must have been put. * * If the profile was referenced from a task context, free_profile() will * be called from an rcu callback routine, so we must not sleep here. */void aa_free_profile(struct aa_profile *profile){ struct rhashtable *rht;
AA_DEBUG(DEBUG_POLICY, "%s(%p)\n", __func__, profile);
if (!profile) return;
/* free children profiles */ aa_policy_destroy(&profile->base); aa_put_profile(rcu_access_pointer(profile->parent));
aa_put_ns(profile->ns); kfree_sensitive(profile->rename); kfree_sensitive(profile->disconnected);
free_attachment(&profile->attach);
/* * at this point there are no tasks that can have a reference * to rules */ for (int i = 0; i < profile->n_rules; i++) free_ruleset(profile->label.rules[i]);
kfree_sensitive(profile->dirname);
if (profile->data) { rht = profile->data; profile->data = NULL; rhashtable_free_and_destroy(rht, aa_free_data, NULL); kfree_sensitive(rht); }
kfree_sensitive(profile->hash); aa_put_profile_loaddata(profile->rawdata); aa_label_destroy(&profile->label);
kfree_sensitive(profile);}
/** * aa_alloc_profile - allocate, initialize and return a new profile * @hname: name of the profile (NOT NULL) * @proxy: proxy to use OR null if to allocate a new one * @gfp: allocation type * * Returns: refcount profile or NULL on failure */struct aa_profile *aa_alloc_profile(const char *hname, struct aa_proxy *proxy, gfp_t gfp){ struct aa_profile *profile;
/* freed by free_profile - usually through aa_put_profile * this adds space for a single ruleset in the rules section of the * label */ profile = kzalloc_flex(*profile, label.rules, 1, gfp); if (!profile) return NULL;
if (!aa_policy_init(&profile->base, NULL, hname, gfp)) goto fail; if (!aa_label_init(&profile->label, 1, gfp)) goto fail;
/* allocate the first ruleset, but leave it empty */ profile->label.rules[0] = aa_alloc_ruleset(gfp); if (!profile->label.rules[0]) goto fail; profile->n_rules = 1;
/* update being set needed by fs interface */ if (!proxy) { proxy = aa_alloc_proxy(&profile->label, gfp); if (!proxy) goto fail; } else aa_get_proxy(proxy); profile->label.proxy = proxy;
profile->label.hname = profile->base.hname; profile->label.flags |= FLAG_PROFILE; profile->label.vec[0] = profile;
profile->signal = SIGKILL; /* refcount released by caller */ return profile;
fail: aa_free_profile(profile);
return NULL;}
static inline bool ANY_RULE_MEDIATES(struct aa_profile *profile, unsigned char class){ int i;
for (i = 0; i < profile->n_rules; i++) { if (RULE_MEDIATES(profile->label.rules[i], class)) return true; } return false;}
/* set of rules that are mediated by unconfined */static int unconfined_mediates[] = { AA_CLASS_NS, AA_CLASS_IO_URING, 0 };
/* must be called after profile rulesets and start information is setup */void aa_compute_profile_mediates(struct aa_profile *profile){ int c;
if (profile_unconfined(profile)) { int *pos;
for (pos = unconfined_mediates; *pos; pos++) { if (ANY_RULE_MEDIATES(profile, *pos)) profile->label.mediates |= ((u64) 1) << AA_CLASS_NS; } return; } for (c = 0; c <= AA_CLASS_LAST; c++) { if (ANY_RULE_MEDIATES(profile, c)) profile->label.mediates |= ((u64) 1) << c; }}
/* TODO: profile accounting - setup in remove */
/** * __strn_find_child - find a profile on @head list using substring of @name * @head: list to search (NOT NULL) * @name: name of profile (NOT NULL) * @len: length of @name substring to match * * Requires: rcu_read_lock be held * * Returns: unrefcounted profile ptr, or NULL if not found */static struct aa_profile *__strn_find_child(struct list_head *head, const char *name, int len){ return (struct aa_profile *)__policy_strn_find(head, name, len);}
/** * __find_child - find a profile on @head list with a name matching @name * @head: list to search (NOT NULL) * @name: name of profile (NOT NULL) * * Requires: rcu_read_lock be held * * Returns: unrefcounted profile ptr, or NULL if not found */static struct aa_profile *__find_child(struct list_head *head, const char *name){ return __strn_find_child(head, name, strlen(name));}
/** * aa_find_child - find a profile by @name in @parent * @parent: profile to search (NOT NULL) * @name: profile name to search for (NOT NULL) * * Returns: a refcounted profile or NULL if not found */struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name){ struct aa_profile *profile;
rcu_read_lock(); do { profile = __find_child(&parent->base.profiles, name); } while (profile && !aa_get_profile_not0(profile)); rcu_read_unlock();
/* refcount released by caller */ return profile;}
/** * __lookup_parent - lookup the parent of a profile of name @hname * @ns: namespace to lookup profile in (NOT NULL) * @hname: hierarchical profile name to find parent of (NOT NULL) * * Lookups up the parent of a fully qualified profile name, the profile * that matches hname does not need to exist, in general this * is used to load a new profile. * * Requires: rcu_read_lock be held * * Returns: unrefcounted policy or NULL if not found */static struct aa_policy *__lookup_parent(struct aa_ns *ns, const char *hname){ struct aa_policy *policy; struct aa_profile *profile = NULL; char *split;
policy = &ns->base;
for (split = strstr(hname, "//"); split;) { profile = __strn_find_child(&policy->profiles, hname, split - hname); if (!profile) return NULL; policy = &profile->base; hname = split + 2; split = strstr(hname, "//"); } if (!profile) return &ns->base; return &profile->base;}
/** * __create_missing_ancestors - create place holders for missing ancestors * @ns: namespace to lookup profile in (NOT NULL) * @hname: hierarchical profile name to find parent of (NOT NULL) * @gfp: type of allocation. * * Requires: ns mutex lock held * * Return: unrefcounted parent policy on success or %NULL if error creating * place holder profiles. */static struct aa_policy *__create_missing_ancestors(struct aa_ns *ns, const char *hname, gfp_t gfp){ struct aa_policy *policy; struct aa_profile *parent, *profile = NULL; char *split;
AA_BUG(!ns); AA_BUG(!hname);
policy = &ns->base;
for (split = strstr(hname, "//"); split;) { parent = profile; profile = __strn_find_child(&policy->profiles, hname, split - hname); if (!profile) { const char *name = kstrndup(hname, split - hname, gfp); if (!name) return NULL; profile = aa_alloc_null(parent, name, gfp); kfree(name); if (!profile) return NULL; if (!parent) profile->ns = aa_get_ns(ns); } policy = &profile->base; hname = split + 2; split = strstr(hname, "//"); } if (!profile) return &ns->base; return &profile->base;}
/** * __lookupn_profile - lookup the profile matching @hname * @base: base list to start looking up profile name from (NOT NULL) * @hname: hierarchical profile name (NOT NULL) * @n: length of @hname * * Requires: rcu_read_lock be held * * Returns: unrefcounted profile pointer or NULL if not found * * Do a relative name lookup, recursing through profile tree. */static struct aa_profile *__lookupn_profile(struct aa_policy *base, const char *hname, size_t n){ struct aa_profile *profile = NULL; const char *split;
for (split = strnstr(hname, "//", n); split; split = strnstr(hname, "//", n)) { profile = __strn_find_child(&base->profiles, hname, split - hname); if (!profile) return NULL;
base = &profile->base; n -= split + 2 - hname; hname = split + 2; }
if (n) return __strn_find_child(&base->profiles, hname, n); return NULL;}
static struct aa_profile *__lookup_profile(struct aa_policy *base, const char *hname){ return __lookupn_profile(base, hname, strlen(hname));}
/** * aa_lookupn_profile - find a profile by its full or partial name * @ns: the namespace to start from (NOT NULL) * @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL) * @n: size of @hname * * Returns: refcounted profile or NULL if not found */struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname, size_t n){ struct aa_profile *profile;
rcu_read_lock(); do { profile = __lookupn_profile(&ns->base, hname, n); } while (profile && !aa_get_profile_not0(profile)); rcu_read_unlock();
/* the unconfined profile is not in the regular profile list */ if (!profile && strncmp(hname, "unconfined", n) == 0) profile = aa_get_newest_profile(ns->unconfined);
/* refcount released by caller */ return profile;}
struct aa_profile *aa_fqlookupn_profile(struct aa_label *base, const char *fqname, size_t n){ struct aa_profile *profile; struct aa_ns *ns; const char *name, *ns_name; size_t ns_len;
name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len); if (ns_name) { ns = aa_lookupn_ns(labels_ns(base), ns_name, ns_len); if (!ns) return NULL; } else ns = aa_get_ns(labels_ns(base));
if (name) profile = aa_lookupn_profile(ns, name, n - (name - fqname)); else if (ns) /* default profile for ns, currently unconfined */ profile = aa_get_newest_profile(ns->unconfined); else profile = NULL; aa_put_ns(ns);
return profile;}
struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name, gfp_t gfp){ struct aa_profile *profile; struct aa_ruleset *rules;
profile = aa_alloc_profile(name, NULL, gfp); if (!profile) return NULL;
/* TODO: ideally we should inherit abi from parent */ profile->label.flags |= FLAG_NULL; profile->attach.xmatch = aa_get_pdb(nullpdb); rules = profile->label.rules[0]; rules->file = aa_get_pdb(nullpdb); rules->policy = aa_get_pdb(nullpdb); aa_compute_profile_mediates(profile);
if (parent) { profile->path_flags = parent->path_flags; /* override/inherit what is mediated from parent */ profile->label.mediates = parent->label.mediates; /* released on free_profile */ rcu_assign_pointer(profile->parent, aa_get_profile(parent)); profile->ns = aa_get_ns(parent->ns); }
return profile;}
/** * __aa_new_learning_profile - create or find a null-X learning profile * @parent: profile that caused this profile to be created (NOT NULL) * @hat: true if the null- learning profile is a hat * @base: name to base the null profile off of * @gfp: type of allocation * * Find/Create a null- complain mode profile used in learning mode. The * name of the profile is unique and follows the format of parent//null-XXX. * where XXX is based on the @name or if that fails or is not supplied * a unique number * * null profiles are added to the profile list but the list does not * hold a count on them so that they are automatically released when * not in use. * * Returns: new refcounted profile else NULL on failure */struct aa_profile *__aa_new_learning_profile(struct aa_profile *parent, bool hat, const char *base, gfp_t gfp){ struct aa_profile *p, *profile; const char *bname; char *name = NULL; size_t name_sz;
AA_BUG(!parent); AA_BUG(!mutex_is_locked(&parent->ns->lock));
if (base) { name_sz = strlen(parent->base.hname) + 8 + strlen(base); name = kmalloc(name_sz, gfp); if (name) { snprintf(name, name_sz, "%s//null-%s", parent->base.hname, base); goto name; } /* fall through to try shorter uniq */ }
name_sz = strlen(parent->base.hname) + 2 + 7 + 8; name = kmalloc(name_sz, gfp); if (!name) return NULL; snprintf(name, name_sz, "%s//null-%x", parent->base.hname, atomic_inc_return(&parent->ns->uniq_null));
name: /* lookup to see if this is a dup creation */ bname = basename(name); profile = aa_find_child(parent, bname); if (profile) goto out;
profile = aa_alloc_null(parent, name, gfp); if (!profile) goto fail; profile->mode = APPARMOR_COMPLAIN; if (hat) profile->label.flags |= FLAG_HAT;
p = __find_child(&parent->base.profiles, bname); if (p) { aa_free_profile(profile); profile = aa_get_profile(p); } else { __add_profile(&parent->base.profiles, profile); }
/* refcount released by caller */out: kfree(name);
return profile;
fail: kfree(name); aa_free_profile(profile); return NULL;}
struct aa_profile *aa_new_learning_profile(struct aa_profile *parent, bool hat, const char *base, gfp_t gfp){ struct aa_profile *profile;
mutex_lock_nested(&parent->ns->lock, parent->ns->level); profile = __aa_new_learning_profile(parent, hat, base, gfp); mutex_unlock(&parent->ns->lock);
return profile;}
/** * replacement_allowed - test to see if replacement is allowed * @profile: profile to test if it can be replaced (MAYBE NULL) * @noreplace: true if replacement shouldn't be allowed but addition is okay * @info: Returns - info about why replacement failed (NOT NULL) * * Returns: %0 if replacement allowed else error code */static int replacement_allowed(struct aa_profile *profile, int noreplace, const char **info){ if (profile) { if (profile->label.flags & FLAG_IMMUTIBLE) { *info = "cannot replace immutable profile"; return -EPERM; } else if (noreplace) { *info = "profile already exists"; return -EEXIST; } } return 0;}
/* audit callback for net specific fields */static void audit_cb(struct audit_buffer *ab, void *va){ struct common_audit_data *sa = va; struct apparmor_audit_data *ad = aad(sa);
if (ad->iface.ns) { audit_log_format(ab, " ns="); audit_log_untrustedstring(ab, ad->iface.ns); }}
/** * audit_policy - Do auditing of policy changes * @subj_label: label to check if it can manage policy * @op: policy operation being performed * @ns_name: name of namespace being manipulated * @name: name of profile being manipulated (NOT NULL) * @info: any extra information to be audited (MAYBE NULL) * @error: error code * * Returns: the error to be returned after audit is done */static int audit_policy(struct aa_label *subj_label, const char *op, const char *ns_name, const char *name, const char *info, int error){ DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, op);
ad.iface.ns = ns_name; ad.name = name; ad.info = info; ad.error = error; ad.subj_label = subj_label;
aa_audit_msg(AUDIT_APPARMOR_STATUS, &ad, audit_cb);
return error;}
/* don't call out to other LSMs in the stack for apparmor policy admin * permissions */static int policy_ns_capable(const struct cred *subj_cred, struct aa_label *label, struct user_namespace *userns, int cap){ int err;
/* check for MAC_ADMIN cap in cred */ err = cap_capable(subj_cred, userns, cap, CAP_OPT_NONE); if (!err) err = aa_capable(subj_cred, label, cap, CAP_OPT_NONE);
return err;}
/** * aa_policy_view_capable - check if viewing policy in at @ns is allowed * @subj_cred: cred of subject * @label: label that is trying to view policy in ns * @ns: namespace being viewed by @label (may be NULL if @label's ns) * * Returns: true if viewing policy is allowed * * If @ns is NULL then the namespace being viewed is assumed to be the * tasks current namespace. */bool aa_policy_view_capable(const struct cred *subj_cred, struct aa_label *label, struct aa_ns *ns){ struct user_namespace *user_ns = subj_cred->user_ns; struct aa_ns *view_ns = labels_view(label); bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) || in_egroup_p(make_kgid(user_ns, 0)); bool response = false; if (!ns) ns = view_ns;
if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) && (user_ns == &init_user_ns || (unprivileged_userns_apparmor_policy != 0 && user_ns->level == view_ns->level))) response = true;
return response;}
bool aa_policy_admin_capable(const struct cred *subj_cred, struct aa_label *label, struct aa_ns *ns){ struct user_namespace *user_ns = subj_cred->user_ns; bool capable = policy_ns_capable(subj_cred, label, user_ns, CAP_MAC_ADMIN) == 0;
AA_DEBUG(DEBUG_POLICY, "cap_mac_admin? %d\n", capable); AA_DEBUG(DEBUG_POLICY, "policy locked? %d\n", aa_g_lock_policy);
return aa_policy_view_capable(subj_cred, label, ns) && capable && !aa_g_lock_policy;}
bool aa_current_policy_view_capable(struct aa_ns *ns){ struct aa_label *label; bool needput, res;
label = __begin_current_label_crit_section(&needput); res = aa_policy_view_capable(current_cred(), label, ns); __end_current_label_crit_section(label, needput);
return res;}
bool aa_current_policy_admin_capable(struct aa_ns *ns){ struct aa_label *label; bool needput, res;
label = __begin_current_label_crit_section(&needput); res = aa_policy_admin_capable(current_cred(), label, ns); __end_current_label_crit_section(label, needput);
return res;}
static bool is_subset_of_obj_privilege(const struct cred *cred, struct aa_label *label, const struct cred *ocred){ if (cred == ocred) return true;
if (!aa_label_is_subset(label, cred_label(ocred))) return false; /* don't allow crossing userns for now */ if (cred->user_ns != ocred->user_ns) return false; if (!cap_issubset(cred->cap_inheritable, ocred->cap_inheritable)) return false; if (!cap_issubset(cred->cap_permitted, ocred->cap_permitted)) return false; if (!cap_issubset(cred->cap_effective, ocred->cap_effective)) return false; if (!cap_issubset(cred->cap_bset, ocred->cap_bset)) return false; if (!cap_issubset(cred->cap_ambient, ocred->cap_ambient)) return false; return true;}
/** * aa_may_manage_policy - can the current task manage policy * @subj_cred: subjects cred * @label: label to check if it can manage policy * @ns: namespace being managed by @label (may be NULL if @label's ns) * @ocred: object cred if request is coming from an open object * @mask: contains the policy manipulation operation being done * * Returns: 0 if the task is allowed to manipulate policy else error */int aa_may_manage_policy(const struct cred *subj_cred, struct aa_label *label, struct aa_ns *ns, const struct cred *ocred, u32 mask){ const char *op;
if (mask & AA_MAY_REMOVE_POLICY) op = OP_PROF_RM; else if (mask & AA_MAY_REPLACE_POLICY) op = OP_PROF_REPL; else op = OP_PROF_LOAD;
/* check if loading policy is locked out */ if (aa_g_lock_policy) return audit_policy(label, op, NULL, NULL, "policy_locked", -EACCES);
if (ocred && !is_subset_of_obj_privilege(subj_cred, label, ocred)) return audit_policy(label, op, NULL, NULL, "not privileged for target profile", -EACCES);
if (!aa_policy_admin_capable(subj_cred, label, ns)) return audit_policy(label, op, NULL, NULL, "not policy admin", -EACCES);
/* TODO: add fine grained mediation of policy loads */ return 0;}
static struct aa_profile *__list_lookup_parent(struct list_head *lh, struct aa_profile *profile){ const char *base = basename(profile->base.hname); long len = base - profile->base.hname; struct aa_load_ent *ent;
/* parent won't have trailing // so remove from len */ if (len <= 2) return NULL; len -= 2;
list_for_each_entry(ent, lh, list) { if (ent->new == profile) continue; if (strncmp(ent->new->base.hname, profile->base.hname, len) == 0 && ent->new->base.hname[len] == 0) return ent->new; }
return NULL;}
/** * __replace_profile - replace @old with @new on a list * @old: profile to be replaced (NOT NULL) * @new: profile to replace @old with (NOT NULL) * * Will duplicate and refcount elements that @new inherits from @old * and will inherit @old children. * * refcount @new for list, put @old list refcount * * Requires: namespace list lock be held, or list not be shared */static void __replace_profile(struct aa_profile *old, struct aa_profile *new){ struct aa_profile *child, *tmp;
if (!list_empty(&old->base.profiles)) { LIST_HEAD(lh); list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
list_for_each_entry_safe(child, tmp, &lh, base.list) { struct aa_profile *p;
list_del_init(&child->base.list); p = __find_child(&new->base.profiles, child->base.name); if (p) { /* @p replaces @child */ __replace_profile(child, p); continue; }
/* inherit @child and its children */ /* TODO: update hname of inherited children */ /* list refcount transferred to @new */ p = aa_deref_parent(child); rcu_assign_pointer(child->parent, aa_get_profile(new)); list_add_rcu(&child->base.list, &new->base.profiles); aa_put_profile(p); } }
if (!rcu_access_pointer(new->parent)) { struct aa_profile *parent = aa_deref_parent(old); rcu_assign_pointer(new->parent, aa_get_profile(parent)); } aa_label_replace(&old->label, &new->label); /* migrate dents must come after label replacement b/c update */ __aafs_profile_migrate_dents(old, new);
if (list_empty(&new->base.list)) { /* new is not on a list already */ list_replace_rcu(&old->base.list, &new->base.list); aa_get_profile(new); aa_put_profile(old); } else __list_remove_profile(old);}
/** * __lookup_replace - lookup replacement information for a profile * @ns: namespace the lookup occurs in * @hname: name of profile to lookup * @noreplace: true if not replacing an existing profile * @p: Returns - profile to be replaced * @info: Returns - info string on why lookup failed * * Returns: profile to replace (no ref) on success else ptr error */static int __lookup_replace(struct aa_ns *ns, const char *hname, bool noreplace, struct aa_profile **p, const char **info){ *p = aa_get_profile(__lookup_profile(&ns->base, hname)); if (*p) { int error = replacement_allowed(*p, noreplace, info); if (error) { *info = "profile can not be replaced"; return error; } }
return 0;}
static void share_name(struct aa_profile *old, struct aa_profile *new){ aa_put_str(new->base.hname); aa_get_str(old->base.hname); new->base.hname = old->base.hname; new->base.name = old->base.name; new->label.hname = old->label.hname;}
/* Update to newest version of parent after previous replacements * Returns: unrefcount newest version of parent */static struct aa_profile *update_to_newest_parent(struct aa_profile *new){ struct aa_profile *parent, *newest;
parent = rcu_dereference_protected(new->parent, mutex_is_locked(&new->ns->lock)); newest = aa_get_newest_profile(parent);
/* parent replaced in this atomic set? */ if (newest != parent) { aa_put_profile(parent); rcu_assign_pointer(new->parent, newest); } else aa_put_profile(newest);
return newest;}
/** * aa_replace_profiles - replace profile(s) on the profile list * @policy_ns: namespace load is occurring on * @label: label that is attempting to load/replace policy * @mask: permission mask * @udata: serialized data stream (NOT NULL) * @compressed_profile: The userspace-provided compressed profile. May be NULL * @compressed_size: If compressed_data is not NULL, the compressed data size * * unpack and replace a profile on the profile list and uses of that profile * by any task creds via invalidating the old version of the profile, which * tasks will notice to update their own cred. If the profile does not exist * on the profile list it is added. * * Returns: size of data consumed else error code on failure. */ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, u32 mask, struct aa_loaddata *udata, char *compressed_profile, size_t compressed_size){ const char *ns_name = NULL, *info = NULL; struct aa_ns *ns = NULL; struct aa_load_ent *ent, *tmp; struct aa_loaddata *rawdata_ent; const char *op; ssize_t count, error; LIST_HEAD(lh);
op = mask & AA_MAY_REPLACE_POLICY ? OP_PROF_REPL : OP_PROF_LOAD; aa_get_profile_loaddata(udata); /* released below */ error = aa_unpack(udata, &lh, &ns_name, compressed_profile, compressed_size); if (error) goto out;
/* ensure that profiles are all for the same ns * TODO: update locking to remove this constraint. All profiles in * the load set must succeed as a set or the load will * fail. Sort ent list and take ns locks in hierarchy order */ count = 0; list_for_each_entry(ent, &lh, list) { if (ns_name) { if (ent->ns_name && strcmp(ent->ns_name, ns_name) != 0) { info = "policy load has mixed namespaces"; error = -EACCES; goto fail; } } else if (ent->ns_name) { if (count) { info = "policy load has mixed namespaces"; error = -EACCES; goto fail; } ns_name = ent->ns_name; ent->ns_name = NULL; } else count++; } if (ns_name) { ns = aa_prepare_ns(policy_ns ? policy_ns : labels_ns(label), ns_name); if (IS_ERR(ns)) { op = OP_PROF_LOAD; info = "failed to prepare namespace"; error = PTR_ERR(ns); ns = NULL; ent = NULL; goto fail; } } else ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(label));
mutex_lock_nested(&ns->lock, ns->level); /* check for duplicate rawdata blobs: space and file dedup */ if (!list_empty(&ns->rawdata_list)) { list_for_each_entry(rawdata_ent, &ns->rawdata_list, list) { if (aa_rawdata_eq(rawdata_ent, udata)) { struct aa_loaddata *tmp;
/* * Entries remain on rawdata_list with * pcount == 0 until do_ploaddata_rmfs() * runs; only take a live profile ref. */ tmp = aa_get_profile_loaddata_not0(rawdata_ent); if (tmp) { aa_put_profile_loaddata(udata); udata = tmp; break; } } } } /* setup parent and ns info */ list_for_each_entry(ent, &lh, list) { struct aa_policy *policy; struct aa_profile *p;
if (aa_g_export_binary) ent->new->rawdata = aa_get_profile_loaddata(udata); error = __lookup_replace(ns, ent->new->base.hname, !(mask & AA_MAY_REPLACE_POLICY), &ent->old, &info); if (error) goto fail_lock;
if (ent->new->rename) { error = __lookup_replace(ns, ent->new->rename, !(mask & AA_MAY_REPLACE_POLICY), &ent->rename, &info); if (error) goto fail_lock; }
/* released when @new is freed */ ent->new->ns = aa_get_ns(ns);
if (ent->old || ent->rename) continue;
/* no ref on policy only use inside lock */ p = NULL; policy = __lookup_parent(ns, ent->new->base.hname); if (!policy) { /* first check for parent in the load set */ p = __list_lookup_parent(&lh, ent->new); if (!p) { /* * fill in missing parent with null * profile that doesn't have * permissions. This allows for * individual profile loading where * the child is loaded before the * parent, and outside of the current * atomic set. This unfortunately can * happen with some userspaces. The * null profile will be replaced once * the parent is loaded. */ policy = __create_missing_ancestors(ns, ent->new->base.hname, GFP_KERNEL); if (!policy) { error = -ENOENT; info = "parent does not exist"; goto fail_lock; } } } if (!p && policy != &ns->base) /* released on profile replacement or free_profile */ p = (struct aa_profile *) policy; rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); }
/* create new fs entries for introspection if needed */ if (!udata->dents[AAFS_LOADDATA_DIR] && aa_g_export_binary) { error = __aa_fs_create_rawdata(ns, udata); if (error) { info = "failed to create raw_data dir and files"; ent = NULL; goto fail_lock; } } list_for_each_entry(ent, &lh, list) { if (!ent->old) { struct dentry *parent; if (rcu_access_pointer(ent->new->parent)) { struct aa_profile *p; p = aa_deref_parent(ent->new); parent = prof_child_dir(p); } else parent = ns_subprofs_dir(ent->new->ns); error = __aafs_profile_mkdir(ent->new, parent); }
if (error) { info = "failed to create"; goto fail_lock; } }
/* Done with checks that may fail - do actual replacement */ __aa_bump_ns_revision(ns); if (aa_g_export_binary) __aa_loaddata_update(udata, ns->revision); list_for_each_entry_safe(ent, tmp, &lh, list) { list_del_init(&ent->list); op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
if (ent->old && ent->old->rawdata == ent->new->rawdata && ent->new->rawdata) { /* dedup actual profile replacement */ audit_policy(label, op, ns_name, ent->new->base.hname, "same as current profile, skipping", error); /* break refcount cycle with proxy. */ aa_put_proxy(ent->new->label.proxy); ent->new->label.proxy = NULL; goto skip; }
if (!aa_g_export_binary) { if (ent->old && ent->old->rawdata && ent->old->dents[AAFS_LOADDATA_DIR]) { /* remove rawdata symlinks because the symlink * target will be removed */ __aa_remove_rawdata_symlink_dents(ent->old); } }
/* * TODO: finer dedup based on profile range in data. Load set * can differ but profile may remain unchanged */ audit_policy(label, op, ns_name, ent->new->base.hname, NULL, error);
if (ent->old) { share_name(ent->old, ent->new); __replace_profile(ent->old, ent->new); if (aa_g_export_binary) { /* recreate rawdata symlinks */ if (!ent->old->rawdata) __aa_create_rawdata_symlink_dents(ent->new); } } else { struct list_head *lh;
if (rcu_access_pointer(ent->new->parent)) { struct aa_profile *parent;
parent = update_to_newest_parent(ent->new); lh = &parent->base.profiles; } else lh = &ns->base.profiles; __add_profile(lh, ent->new); } skip: aa_load_ent_free(ent); } __aa_labelset_update_subtree(ns); mutex_unlock(&ns->lock);
out: aa_put_ns(ns);
ssize_t udata_sz = udata->size;
aa_put_profile_loaddata(udata); kfree(ns_name);
if (error) return error; return udata_sz;
fail_lock: mutex_unlock(&ns->lock);
/* audit cause of failure */ op = (ent && !ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;fail: audit_policy(label, op, ns_name, ent ? ent->new->base.hname : NULL, info, error); /* audit status that rest of profiles in the atomic set failed too */ info = "valid profile in failed atomic policy load"; list_for_each_entry(tmp, &lh, list) { if (tmp == ent) { info = "unchecked profile in failed atomic policy load"; /* skip entry that caused failure */ continue; } op = (!tmp->old) ? OP_PROF_LOAD : OP_PROF_REPL; audit_policy(label, op, ns_name, tmp->new->base.hname, info, error); } list_for_each_entry_safe(ent, tmp, &lh, list) { list_del_init(&ent->list); aa_load_ent_free(ent); }
goto out;}
/** * aa_remove_profiles - remove profile(s) from the system * @policy_ns: namespace the remove is being done from * @subj: label attempting to remove policy * @fqname: name of the profile or namespace to remove (NOT NULL) * @size: size of the name * * Remove a profile or sub namespace from the current namespace, so that * they can not be found anymore and mark them as replaced by unconfined * * NOTE: removing confinement does not restore rlimits to preconfinement values * * Returns: size of data consume else error code if fails */ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj, char *fqname, size_t size){ struct aa_ns *ns = NULL; struct aa_profile *profile = NULL; const char *name = fqname, *info = NULL; const char *ns_name = NULL; ssize_t error = 0;
if (*fqname == 0) { info = "no profile specified"; error = -ENOENT; goto fail; }
if (fqname[0] == ':') { size_t ns_len;
name = aa_splitn_fqname(fqname, size, &ns_name, &ns_len); /* released below */ ns = aa_lookupn_ns(policy_ns ? policy_ns : labels_ns(subj), ns_name, ns_len); if (!ns) { info = "namespace does not exist"; error = -ENOENT; goto fail; } } else /* released below */ ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(subj));
if (!name) { /* remove namespace - can only happen if fqname[0] == ':' */ mutex_lock_nested(&ns->parent->lock, ns->parent->level); __aa_bump_ns_revision(ns); __aa_remove_ns(ns); mutex_unlock(&ns->parent->lock); } else { /* remove profile */ mutex_lock_nested(&ns->lock, ns->level); profile = aa_get_profile(__lookup_profile(&ns->base, name)); if (!profile) { error = -ENOENT; info = "profile does not exist"; goto fail_ns_lock; } name = profile->base.hname; __aa_bump_ns_revision(ns); __remove_profile(profile); __aa_labelset_update_subtree(ns); mutex_unlock(&ns->lock); }
/* don't fail removal if audit fails */ (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, error); aa_put_ns(ns); aa_put_profile(profile); return size;
fail_ns_lock: mutex_unlock(&ns->lock); aa_put_ns(ns);
fail: (void) audit_policy(subj, OP_PROF_RM, ns_name, name, info, error); return error;}