| /* |
| * AppArmor security module |
| * |
| * This file contains AppArmor policy manipulation functions |
| * |
| * Copyright (C) 1998-2008 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. |
| * |
| * |
| * 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/context.h" |
| #include "include/file.h" |
| #include "include/ipc.h" |
| #include "include/match.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; |
| |
| const char *const aa_profile_mode_names[] = { |
| "enforce", |
| "complain", |
| "kill", |
| "unconfined", |
| }; |
| |
| /* requires profile list write lock held */ |
| void __aa_update_proxy(struct aa_profile *orig, struct aa_profile *new) |
| { |
| struct aa_profile *tmp; |
| |
| tmp = rcu_dereference_protected(orig->proxy->profile, |
| mutex_is_locked(&orig->ns->lock)); |
| rcu_assign_pointer(orig->proxy->profile, aa_get_profile(new)); |
| orig->flags |= PFLAG_STALE; |
| aa_put_profile(tmp); |
| } |
| |
| /** |
| * __list_add_profile - add a profile to a list |
| * @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 __list_add_profile(struct list_head *list, |
| struct aa_profile *profile) |
| { |
| list_add_rcu(&profile->base.list, list); |
| /* get list reference */ |
| aa_get_profile(profile); |
| } |
| |
| /** |
| * __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) |
| { |
| list_del_rcu(&profile->base.list); |
| aa_put_profile(profile); |
| } |
| |
| /** |
| * __remove_profile - remove old profile, and children |
| * @profile: profile to be replaced (NOT NULL) |
| * |
| * Requires: namespace list lock be held, or list not be shared |
| */ |
| static void __remove_profile(struct aa_profile *profile) |
| { |
| /* release any children lists first */ |
| __aa_profile_list_release(&profile->base.profiles); |
| /* released by free_profile */ |
| __aa_update_proxy(profile, profile->ns->unconfined); |
| __aa_fs_profile_rmdir(profile); |
| __list_remove_profile(profile); |
| } |
| |
| /** |
| * __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); |
| } |
| |
| |
| static void free_proxy(struct aa_proxy *p) |
| { |
| if (p) { |
| /* r->profile will not be updated any more as r is dead */ |
| aa_put_profile(rcu_dereference_protected(p->profile, true)); |
| kzfree(p); |
| } |
| } |
| |
| |
| void aa_free_proxy_kref(struct kref *kref) |
| { |
| struct aa_proxy *p = container_of(kref, struct aa_proxy, count); |
| |
| free_proxy(p); |
| } |
| |
| /** |
| * 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; |
| |
| kzfree(data->data); |
| kzfree(data->key); |
| kzfree(data); |
| } |
| |
| /** |
| * 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("%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); |
| kzfree(profile->rename); |
| |
| aa_free_file_rules(&profile->file); |
| aa_free_cap_rules(&profile->caps); |
| aa_free_rlimit_rules(&profile->rlimits); |
| |
| kzfree(profile->dirname); |
| aa_put_dfa(profile->xmatch); |
| aa_put_dfa(profile->policy.dfa); |
| aa_put_proxy(profile->proxy); |
| |
| if (profile->data) { |
| rht = profile->data; |
| profile->data = NULL; |
| rhashtable_free_and_destroy(rht, aa_free_data, NULL); |
| kzfree(rht); |
| } |
| |
| kzfree(profile->hash); |
| aa_put_loaddata(profile->rawdata); |
| kzfree(profile); |
| } |
| |
| /** |
| * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref) |
| * @head: rcu_head callback for freeing of a profile (NOT NULL) |
| */ |
| static void aa_free_profile_rcu(struct rcu_head *head) |
| { |
| struct aa_profile *p = container_of(head, struct aa_profile, rcu); |
| if (p->flags & PFLAG_NS_COUNT) |
| aa_free_ns(p->ns); |
| else |
| aa_free_profile(p); |
| } |
| |
| /** |
| * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile) |
| * @kr: kref callback for freeing of a profile (NOT NULL) |
| */ |
| void aa_free_profile_kref(struct kref *kref) |
| { |
| struct aa_profile *p = container_of(kref, struct aa_profile, count); |
| call_rcu(&p->rcu, aa_free_profile_rcu); |
| } |
| |
| /** |
| * aa_alloc_profile - allocate, initialize and return a new profile |
| * @hname: name of the profile (NOT NULL) |
| * @gfp: allocation type |
| * |
| * Returns: refcount profile or NULL on failure |
| */ |
| struct aa_profile *aa_alloc_profile(const char *hname, gfp_t gfp) |
| { |
| struct aa_profile *profile; |
| |
| /* freed by free_profile - usually through aa_put_profile */ |
| profile = kzalloc(sizeof(*profile), gfp); |
| if (!profile) |
| return NULL; |
| |
| profile->proxy = kzalloc(sizeof(struct aa_proxy), gfp); |
| if (!profile->proxy) |
| goto fail; |
| kref_init(&profile->proxy->count); |
| |
| if (!aa_policy_init(&profile->base, NULL, hname, gfp)) |
| goto fail; |
| kref_init(&profile->count); |
| |
| /* refcount released by caller */ |
| return profile; |
| |
| fail: |
| kzfree(profile->proxy); |
| kzfree(profile); |
| |
| return NULL; |
| } |
| |
| /** |
| * aa_new_null_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_null_profile(struct aa_profile *parent, bool hat, |
| const char *base, gfp_t gfp) |
| { |
| struct aa_profile *profile; |
| char *name; |
| |
| AA_BUG(!parent); |
| |
| if (base) { |
| name = kmalloc(strlen(parent->base.hname) + 8 + strlen(base), |
| gfp); |
| if (name) { |
| sprintf(name, "%s//null-%s", parent->base.hname, base); |
| goto name; |
| } |
| /* fall through to try shorter uniq */ |
| } |
| |
| name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, gfp); |
| if (!name) |
| return NULL; |
| sprintf(name, "%s//null-%x", parent->base.hname, |
| atomic_inc_return(&parent->ns->uniq_null)); |
| |
| name: |
| /* lookup to see if this is a dup creation */ |
| profile = aa_find_child(parent, basename(name)); |
| if (profile) |
| goto out; |
| |
| profile = aa_alloc_profile(name, gfp); |
| if (!profile) |
| goto fail; |
| |
| profile->mode = APPARMOR_COMPLAIN; |
| profile->flags |= PFLAG_NULL; |
| if (hat) |
| profile->flags |= PFLAG_HAT; |
| profile->path_flags = parent->path_flags; |
| |
| /* released on free_profile */ |
| rcu_assign_pointer(profile->parent, aa_get_profile(parent)); |
| profile->ns = aa_get_ns(parent->ns); |
| profile->file.dfa = aa_get_dfa(nulldfa); |
| profile->policy.dfa = aa_get_dfa(nulldfa); |
| |
| mutex_lock(&profile->ns->lock); |
| __list_add_profile(&parent->base.profiles, profile); |
| mutex_unlock(&profile->ns->lock); |
| |
| /* refcount released by caller */ |
| out: |
| kfree(name); |
| |
| return profile; |
| |
| fail: |
| kfree(name); |
| aa_free_profile(profile); |
| return NULL; |
| } |
| |
| /* TODO: profile accounting - setup in remove */ |
| |
| /** |
| * __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 (struct aa_profile *)__policy_find(head, name); |
| } |
| |
| /** |
| * __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); |
| } |
| |
| /** |
| * 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; |
| } |
| |
| /** |
| * __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_lookup_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_lookup_profile(struct aa_ns *ns, const char *hname) |
| { |
| return aa_lookupn_profile(ns, hname, strlen(hname)); |
| } |
| |
| struct aa_profile *aa_fqlookupn_profile(struct aa_profile *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_findn_ns(base->ns, ns_name, ns_len); |
| if (!ns) |
| return NULL; |
| } else |
| ns = aa_get_ns(base->ns); |
| |
| 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; |
| } |
| |
| /** |
| * 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->flags & PFLAG_IMMUTABLE) { |
| *info = "cannot replace immutible 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; |
| |
| if (aad(sa)->iface.ns) { |
| audit_log_format(ab, " ns="); |
| audit_log_untrustedstring(ab, aad(sa)->iface.ns); |
| } |
| } |
| |
| /** |
| * aa_audit_policy - Do auditing of policy changes |
| * @profile: profile to check if it can manage policy |
| * @op: policy operation being performed |
| * @gfp: memory allocation flags |
| * @nsname: name of the ns being manipulated (MAY BE NULL) |
| * @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_profile *profile, const char *op, |
| const char *nsname, const char *name, |
| const char *info, int error) |
| { |
| DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op); |
| |
| aad(&sa)->iface.ns = nsname; |
| aad(&sa)->name = name; |
| aad(&sa)->info = info; |
| aad(&sa)->error = error; |
| |
| return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb); |
| } |
| |
| /** |
| * policy_view_capable - check if viewing policy in at @ns is allowed |
| * ns: namespace being viewed by current task (may be NULL) |
| * 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 policy_view_capable(struct aa_ns *ns) |
| { |
| struct user_namespace *user_ns = current_user_ns(); |
| struct aa_ns *view_ns = aa_get_current_ns(); |
| 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; |
| aa_put_ns(view_ns); |
| |
| return response; |
| } |
| |
| bool policy_admin_capable(struct aa_ns *ns) |
| { |
| struct user_namespace *user_ns = current_user_ns(); |
| bool capable = ns_capable(user_ns, CAP_MAC_ADMIN); |
| |
| AA_DEBUG("cap_mac_admin? %d\n", capable); |
| AA_DEBUG("policy locked? %d\n", aa_g_lock_policy); |
| |
| return policy_view_capable(ns) && capable && !aa_g_lock_policy; |
| } |
| |
| /** |
| * aa_may_manage_policy - can the current task manage policy |
| * @profile: profile to check if it can manage policy |
| * @op: the policy manipulation operation being done |
| * |
| * Returns: 0 if the task is allowed to manipulate policy else error |
| */ |
| int aa_may_manage_policy(struct aa_profile *profile, struct aa_ns *ns, |
| const char *op) |
| { |
| /* check if loading policy is locked out */ |
| if (aa_g_lock_policy) |
| return audit_policy(profile, op, NULL, NULL, |
| "policy_locked", -EACCES); |
| |
| if (!policy_admin_capable(ns)) |
| return audit_policy(profile, 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) |
| * @share_proxy: transfer @old->proxy to @new |
| * |
| * 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, |
| bool share_proxy) |
| { |
| 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, share_proxy); |
| 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_update_proxy(old, new); |
| if (share_proxy) { |
| aa_put_proxy(new->proxy); |
| new->proxy = aa_get_proxy(old->proxy); |
| } else if (!rcu_access_pointer(new->proxy->profile)) |
| /* aafs interface uses proxy */ |
| rcu_assign_pointer(new->proxy->profile, |
| aa_get_profile(new)); |
| __aa_fs_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; |
| } |
| |
| /** |
| * aa_replace_profiles - replace profile(s) on the profile list |
| * @view: namespace load is viewed from |
| * @label: label that is attempting to load/replace policy |
| * @noreplace: true if only doing addition, no replacement allowed |
| * @udata: serialized data stream (NOT NULL) |
| * |
| * unpack and replace a profile on the profile list and uses of that profile |
| * by any aa_task_ctx. 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 *view, struct aa_profile *profile, |
| bool noreplace, struct aa_loaddata *udata) |
| { |
| const char *ns_name, *info = NULL; |
| struct aa_ns *ns = NULL; |
| struct aa_load_ent *ent, *tmp; |
| const char *op = OP_PROF_REPL; |
| ssize_t count, error; |
| LIST_HEAD(lh); |
| |
| /* released below */ |
| error = aa_unpack(udata, &lh, &ns_name); |
| if (error) |
| goto out; |
| |
| /* ensure that profiles are all for the same ns |
| * TODO: update locking to remove this constaint. 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; |
| } else |
| count++; |
| } |
| if (ns_name) { |
| ns = aa_prepare_ns(view, 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(view); |
| |
| mutex_lock(&ns->lock); |
| /* setup parent and ns info */ |
| list_for_each_entry(ent, &lh, list) { |
| struct aa_policy *policy; |
| ent->new->rawdata = aa_get_loaddata(udata); |
| error = __lookup_replace(ns, ent->new->base.hname, noreplace, |
| &ent->old, &info); |
| if (error) |
| goto fail_lock; |
| |
| if (ent->new->rename) { |
| error = __lookup_replace(ns, ent->new->rename, |
| noreplace, &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 */ |
| policy = __lookup_parent(ns, ent->new->base.hname); |
| if (!policy) { |
| struct aa_profile *p; |
| p = __list_lookup_parent(&lh, ent->new); |
| if (!p) { |
| error = -ENOENT; |
| info = "parent does not exist"; |
| goto fail_lock; |
| } |
| rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); |
| } else if (policy != &ns->base) { |
| /* released on profile replacement or free_profile */ |
| struct aa_profile *p = (struct aa_profile *) policy; |
| rcu_assign_pointer(ent->new->parent, aa_get_profile(p)); |
| } |
| } |
| |
| /* create new fs entries for introspection if needed */ |
| list_for_each_entry(ent, &lh, list) { |
| if (ent->old) { |
| /* inherit old interface files */ |
| |
| /* if (ent->rename) |
| TODO: support rename */ |
| /* } else if (ent->rename) { |
| TODO: support rename */ |
| } else { |
| 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 = __aa_fs_profile_mkdir(ent->new, parent); |
| } |
| |
| if (error) { |
| info = "failed to create "; |
| goto fail_lock; |
| } |
| } |
| |
| /* Done with checks that may fail - do actual replacement */ |
| 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; |
| |
| audit_policy(profile, op, NULL, ent->new->base.hname, |
| NULL, error); |
| |
| if (ent->old) { |
| __replace_profile(ent->old, ent->new, 1); |
| if (ent->rename) { |
| /* aafs interface uses proxy */ |
| struct aa_proxy *r = ent->new->proxy; |
| rcu_assign_pointer(r->profile, |
| aa_get_profile(ent->new)); |
| __replace_profile(ent->rename, ent->new, 0); |
| } |
| } else if (ent->rename) { |
| /* aafs interface uses proxy */ |
| rcu_assign_pointer(ent->new->proxy->profile, |
| aa_get_profile(ent->new)); |
| __replace_profile(ent->rename, ent->new, 0); |
| } else if (ent->new->parent) { |
| struct aa_profile *parent, *newest; |
| parent = aa_deref_parent(ent->new); |
| newest = aa_get_newest_profile(parent); |
| |
| /* parent replaced in this atomic set? */ |
| if (newest != parent) { |
| aa_get_profile(newest); |
| rcu_assign_pointer(ent->new->parent, newest); |
| aa_put_profile(parent); |
| } |
| /* aafs interface uses proxy */ |
| rcu_assign_pointer(ent->new->proxy->profile, |
| aa_get_profile(ent->new)); |
| __list_add_profile(&newest->base.profiles, ent->new); |
| aa_put_profile(newest); |
| } else { |
| /* aafs interface uses proxy */ |
| rcu_assign_pointer(ent->new->proxy->profile, |
| aa_get_profile(ent->new)); |
| __list_add_profile(&ns->base.profiles, ent->new); |
| } |
| aa_load_ent_free(ent); |
| } |
| mutex_unlock(&ns->lock); |
| |
| out: |
| aa_put_ns(ns); |
| |
| if (error) |
| return error; |
| return udata->size; |
| |
| fail_lock: |
| mutex_unlock(&ns->lock); |
| |
| /* audit cause of failure */ |
| op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL; |
| fail: |
| audit_policy(profile, 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(profile, 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 |
| * @view: namespace the remove is being done from |
| * @subj: profile 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 preconfinemnet values |
| * |
| * Returns: size of data consume else error code if fails |
| */ |
| ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_profile *subj, |
| char *fqname, size_t size) |
| { |
| struct aa_ns *root = NULL, *ns = NULL; |
| struct aa_profile *profile = NULL; |
| const char *name = fqname, *info = NULL; |
| char *ns_name = NULL; |
| ssize_t error = 0; |
| |
| if (*fqname == 0) { |
| info = "no profile specified"; |
| error = -ENOENT; |
| goto fail; |
| } |
| |
| root = view; |
| |
| if (fqname[0] == ':') { |
| name = aa_split_fqname(fqname, &ns_name); |
| /* released below */ |
| ns = aa_find_ns(root, ns_name); |
| if (!ns) { |
| info = "namespace does not exist"; |
| error = -ENOENT; |
| goto fail; |
| } |
| } else |
| /* released below */ |
| ns = aa_get_ns(root); |
| |
| if (!name) { |
| /* remove namespace - can only happen if fqname[0] == ':' */ |
| mutex_lock(&ns->parent->lock); |
| __aa_remove_ns(ns); |
| mutex_unlock(&ns->parent->lock); |
| } else { |
| /* remove profile */ |
| mutex_lock(&ns->lock); |
| 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; |
| __remove_profile(profile); |
| 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; |
| } |