| /* |
| * 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 "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_unpack.h" |
| #include "include/resource.h" |
| |
| |
| /* root profile namespace */ |
| struct aa_namespace *root_ns; |
| |
| const char *const aa_profile_mode_names[] = { |
| "enforce", |
| "complain", |
| "kill", |
| "unconfined", |
| }; |
| |
| /** |
| * hname_tail - find the last component of an hname |
| * @name: hname to find the base profile name component of (NOT NULL) |
| * |
| * Returns: the tail (base profile name) name component of an hname |
| */ |
| static const char *hname_tail(const char *hname) |
| { |
| char *split; |
| hname = strim((char *)hname); |
| for (split = strstr(hname, "//"); split; split = strstr(hname, "//")) |
| hname = split + 2; |
| |
| return hname; |
| } |
| |
| /** |
| * policy_init - initialize a policy structure |
| * @policy: policy to initialize (NOT NULL) |
| * @prefix: prefix name if any is required. (MAYBE NULL) |
| * @name: name of the policy, init will make a copy of it (NOT NULL) |
| * |
| * Note: this fn creates a copy of strings passed in |
| * |
| * Returns: true if policy init successful |
| */ |
| static bool policy_init(struct aa_policy *policy, const char *prefix, |
| const char *name) |
| { |
| /* freed by policy_free */ |
| if (prefix) { |
| policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3, |
| GFP_KERNEL); |
| if (policy->hname) |
| sprintf(policy->hname, "%s//%s", prefix, name); |
| } else |
| policy->hname = kstrdup(name, GFP_KERNEL); |
| if (!policy->hname) |
| return 0; |
| /* base.name is a substring of fqname */ |
| policy->name = (char *)hname_tail(policy->hname); |
| INIT_LIST_HEAD(&policy->list); |
| INIT_LIST_HEAD(&policy->profiles); |
| |
| return 1; |
| } |
| |
| /** |
| * policy_destroy - free the elements referenced by @policy |
| * @policy: policy that is to have its elements freed (NOT NULL) |
| */ |
| static void policy_destroy(struct aa_policy *policy) |
| { |
| /* still contains profiles -- invalid */ |
| if (on_list_rcu(&policy->profiles)) { |
| AA_ERROR("%s: internal error, " |
| "policy '%s' still contains profiles\n", |
| __func__, policy->name); |
| BUG(); |
| } |
| if (on_list_rcu(&policy->list)) { |
| AA_ERROR("%s: internal error, policy '%s' still on list\n", |
| __func__, policy->name); |
| BUG(); |
| } |
| |
| /* don't free name as its a subset of hname */ |
| kzfree(policy->hname); |
| } |
| |
| /** |
| * __policy_find - find a policy by @name on a policy list |
| * @head: list to search (NOT NULL) |
| * @name: name to search for (NOT NULL) |
| * |
| * Requires: rcu_read_lock be held |
| * |
| * Returns: unrefcounted policy that match @name or NULL if not found |
| */ |
| static struct aa_policy *__policy_find(struct list_head *head, const char *name) |
| { |
| struct aa_policy *policy; |
| |
| list_for_each_entry_rcu(policy, head, list) { |
| if (!strcmp(policy->name, name)) |
| return policy; |
| } |
| return NULL; |
| } |
| |
| /** |
| * __policy_strn_find - find a policy that's name matches @len chars of @str |
| * @head: list to search (NOT NULL) |
| * @str: string to search for (NOT NULL) |
| * @len: length of match required |
| * |
| * Requires: rcu_read_lock be held |
| * |
| * Returns: unrefcounted policy that match @str or NULL if not found |
| * |
| * if @len == strlen(@strlen) then this is equiv to __policy_find |
| * other wise it allows searching for policy by a partial match of name |
| */ |
| static struct aa_policy *__policy_strn_find(struct list_head *head, |
| const char *str, int len) |
| { |
| struct aa_policy *policy; |
| |
| list_for_each_entry_rcu(policy, head, list) { |
| if (aa_strneq(policy->name, str, len)) |
| return policy; |
| } |
| |
| return NULL; |
| } |
| |
| /* |
| * Routines for AppArmor namespaces |
| */ |
| |
| static const char *hidden_ns_name = "---"; |
| /** |
| * aa_ns_visible - test if @view is visible from @curr |
| * @curr: namespace to treat as the parent (NOT NULL) |
| * @view: namespace to test if visible from @curr (NOT NULL) |
| * |
| * Returns: true if @view is visible from @curr else false |
| */ |
| bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view) |
| { |
| if (curr == view) |
| return true; |
| |
| for ( ; view; view = view->parent) { |
| if (view->parent == curr) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * aa_na_name - Find the ns name to display for @view from @curr |
| * @curr - current namespace (NOT NULL) |
| * @view - namespace attempting to view (NOT NULL) |
| * |
| * Returns: name of @view visible from @curr |
| */ |
| const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view) |
| { |
| /* if view == curr then the namespace name isn't displayed */ |
| if (curr == view) |
| return ""; |
| |
| if (aa_ns_visible(curr, view)) { |
| /* at this point if a ns is visible it is in a view ns |
| * thus the curr ns.hname is a prefix of its name. |
| * Only output the virtualized portion of the name |
| * Add + 2 to skip over // separating curr hname prefix |
| * from the visible tail of the views hname |
| */ |
| return view->base.hname + strlen(curr->base.hname) + 2; |
| } else |
| return hidden_ns_name; |
| } |
| |
| /** |
| * alloc_namespace - allocate, initialize and return a new namespace |
| * @prefix: parent namespace name (MAYBE NULL) |
| * @name: a preallocated name (NOT NULL) |
| * |
| * Returns: refcounted namespace or NULL on failure. |
| */ |
| static struct aa_namespace *alloc_namespace(const char *prefix, |
| const char *name) |
| { |
| struct aa_namespace *ns; |
| |
| ns = kzalloc(sizeof(*ns), GFP_KERNEL); |
| AA_DEBUG("%s(%p)\n", __func__, ns); |
| if (!ns) |
| return NULL; |
| if (!policy_init(&ns->base, prefix, name)) |
| goto fail_ns; |
| |
| INIT_LIST_HEAD(&ns->sub_ns); |
| mutex_init(&ns->lock); |
| |
| /* released by free_namespace */ |
| ns->unconfined = aa_alloc_profile("unconfined"); |
| if (!ns->unconfined) |
| goto fail_unconfined; |
| |
| ns->unconfined->flags = PFLAG_IX_ON_NAME_ERROR | |
| PFLAG_IMMUTABLE | PFLAG_NS_COUNT; |
| ns->unconfined->mode = APPARMOR_UNCONFINED; |
| |
| /* ns and ns->unconfined share ns->unconfined refcount */ |
| ns->unconfined->ns = ns; |
| |
| atomic_set(&ns->uniq_null, 0); |
| |
| return ns; |
| |
| fail_unconfined: |
| kzfree(ns->base.hname); |
| fail_ns: |
| kzfree(ns); |
| return NULL; |
| } |
| |
| /** |
| * free_namespace - free a profile namespace |
| * @ns: the namespace to free (MAYBE NULL) |
| * |
| * Requires: All references to the namespace must have been put, if the |
| * namespace was referenced by a profile confining a task, |
| */ |
| static void free_namespace(struct aa_namespace *ns) |
| { |
| if (!ns) |
| return; |
| |
| policy_destroy(&ns->base); |
| aa_put_namespace(ns->parent); |
| |
| ns->unconfined->ns = NULL; |
| aa_free_profile(ns->unconfined); |
| kzfree(ns); |
| } |
| |
| /** |
| * __aa_find_namespace - find a namespace on a list by @name |
| * @head: list to search for namespace on (NOT NULL) |
| * @name: name of namespace to look for (NOT NULL) |
| * |
| * Returns: unrefcounted namespace |
| * |
| * Requires: rcu_read_lock be held |
| */ |
| static struct aa_namespace *__aa_find_namespace(struct list_head *head, |
| const char *name) |
| { |
| return (struct aa_namespace *)__policy_find(head, name); |
| } |
| |
| /** |
| * aa_find_namespace - look up a profile namespace on the namespace list |
| * @root: namespace to search in (NOT NULL) |
| * @name: name of namespace to find (NOT NULL) |
| * |
| * Returns: a refcounted namespace on the list, or NULL if no namespace |
| * called @name exists. |
| * |
| * refcount released by caller |
| */ |
| struct aa_namespace *aa_find_namespace(struct aa_namespace *root, |
| const char *name) |
| { |
| struct aa_namespace *ns = NULL; |
| |
| rcu_read_lock(); |
| ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name)); |
| rcu_read_unlock(); |
| |
| return ns; |
| } |
| |
| /** |
| * aa_prepare_namespace - find an existing or create a new namespace of @name |
| * @name: the namespace to find or add (MAYBE NULL) |
| * |
| * Returns: refcounted namespace or NULL if failed to create one |
| */ |
| static struct aa_namespace *aa_prepare_namespace(const char *name) |
| { |
| struct aa_namespace *ns, *root; |
| |
| root = aa_current_profile()->ns; |
| |
| mutex_lock(&root->lock); |
| |
| /* if name isn't specified the profile is loaded to the current ns */ |
| if (!name) { |
| /* released by caller */ |
| ns = aa_get_namespace(root); |
| goto out; |
| } |
| |
| /* try and find the specified ns and if it doesn't exist create it */ |
| /* released by caller */ |
| ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name)); |
| if (!ns) { |
| ns = alloc_namespace(root->base.hname, name); |
| if (!ns) |
| goto out; |
| if (__aa_fs_namespace_mkdir(ns, ns_subns_dir(root), name)) { |
| AA_ERROR("Failed to create interface for ns %s\n", |
| ns->base.name); |
| free_namespace(ns); |
| ns = NULL; |
| goto out; |
| } |
| ns->parent = aa_get_namespace(root); |
| list_add_rcu(&ns->base.list, &root->sub_ns); |
| /* add list ref */ |
| aa_get_namespace(ns); |
| } |
| out: |
| mutex_unlock(&root->lock); |
| |
| /* return ref */ |
| return ns; |
| } |
| |
| /** |
| * __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); |
| } |
| |
| static void __profile_list_release(struct list_head *head); |
| |
| /** |
| * __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 */ |
| __profile_list_release(&profile->base.profiles); |
| /* released by free_profile */ |
| __aa_update_replacedby(profile, profile->ns->unconfined); |
| __aa_fs_profile_rmdir(profile); |
| __list_remove_profile(profile); |
| } |
| |
| /** |
| * __profile_list_release - remove all profiles on the list and put refs |
| * @head: list of profiles (NOT NULL) |
| * |
| * Requires: namespace lock be held |
| */ |
| static void __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 __ns_list_release(struct list_head *head); |
| |
| /** |
| * destroy_namespace - remove everything contained by @ns |
| * @ns: namespace to have it contents removed (NOT NULL) |
| */ |
| static void destroy_namespace(struct aa_namespace *ns) |
| { |
| if (!ns) |
| return; |
| |
| mutex_lock(&ns->lock); |
| /* release all profiles in this namespace */ |
| __profile_list_release(&ns->base.profiles); |
| |
| /* release all sub namespaces */ |
| __ns_list_release(&ns->sub_ns); |
| |
| if (ns->parent) |
| __aa_update_replacedby(ns->unconfined, ns->parent->unconfined); |
| __aa_fs_namespace_rmdir(ns); |
| mutex_unlock(&ns->lock); |
| } |
| |
| /** |
| * __remove_namespace - remove a namespace and all its children |
| * @ns: namespace to be removed (NOT NULL) |
| * |
| * Requires: ns->parent->lock be held and ns removed from parent. |
| */ |
| static void __remove_namespace(struct aa_namespace *ns) |
| { |
| /* remove ns from namespace list */ |
| list_del_rcu(&ns->base.list); |
| destroy_namespace(ns); |
| aa_put_namespace(ns); |
| } |
| |
| /** |
| * __ns_list_release - remove all profile namespaces on the list put refs |
| * @head: list of profile namespaces (NOT NULL) |
| * |
| * Requires: namespace lock be held |
| */ |
| static void __ns_list_release(struct list_head *head) |
| { |
| struct aa_namespace *ns, *tmp; |
| list_for_each_entry_safe(ns, tmp, head, base.list) |
| __remove_namespace(ns); |
| |
| } |
| |
| /** |
| * aa_alloc_root_ns - allocate the root profile namespace |
| * |
| * Returns: %0 on success else error |
| * |
| */ |
| int __init aa_alloc_root_ns(void) |
| { |
| /* released by aa_free_root_ns - used as list ref*/ |
| root_ns = alloc_namespace(NULL, "root"); |
| if (!root_ns) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| /** |
| * aa_free_root_ns - free the root profile namespace |
| */ |
| void __init aa_free_root_ns(void) |
| { |
| struct aa_namespace *ns = root_ns; |
| root_ns = NULL; |
| |
| destroy_namespace(ns); |
| aa_put_namespace(ns); |
| } |
| |
| |
| static void free_replacedby(struct aa_replacedby *r) |
| { |
| if (r) { |
| /* r->profile will not be updated any more as r is dead */ |
| aa_put_profile(rcu_dereference_protected(r->profile, true)); |
| kzfree(r); |
| } |
| } |
| |
| |
| void aa_free_replacedby_kref(struct kref *kref) |
| { |
| struct aa_replacedby *r = container_of(kref, struct aa_replacedby, |
| count); |
| free_replacedby(r); |
| } |
| |
| /** |
| * 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) |
| { |
| AA_DEBUG("%s(%p)\n", __func__, profile); |
| |
| if (!profile) |
| return; |
| |
| /* free children profiles */ |
| policy_destroy(&profile->base); |
| aa_put_profile(rcu_access_pointer(profile->parent)); |
| |
| aa_put_namespace(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_replacedby(profile->replacedby); |
| |
| kzfree(profile->hash); |
| 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) |
| free_namespace(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) |
| * |
| * Returns: refcount profile or NULL on failure |
| */ |
| struct aa_profile *aa_alloc_profile(const char *hname) |
| { |
| struct aa_profile *profile; |
| |
| /* freed by free_profile - usually through aa_put_profile */ |
| profile = kzalloc(sizeof(*profile), GFP_KERNEL); |
| if (!profile) |
| return NULL; |
| |
| profile->replacedby = kzalloc(sizeof(struct aa_replacedby), GFP_KERNEL); |
| if (!profile->replacedby) |
| goto fail; |
| kref_init(&profile->replacedby->count); |
| |
| if (!policy_init(&profile->base, NULL, hname)) |
| goto fail; |
| kref_init(&profile->count); |
| |
| /* refcount released by caller */ |
| return profile; |
| |
| fail: |
| kzfree(profile->replacedby); |
| kzfree(profile); |
| |
| return NULL; |
| } |
| |
| /** |
| * aa_new_null_profile - create a new 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 |
| * |
| * Create a null- complain mode profile used in learning mode. The name of |
| * the profile is unique and follows the format of parent//null-<uniq>. |
| * |
| * 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, int hat) |
| { |
| struct aa_profile *profile = NULL; |
| char *name; |
| int uniq = atomic_inc_return(&parent->ns->uniq_null); |
| |
| /* freed below */ |
| name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL); |
| if (!name) |
| goto fail; |
| sprintf(name, "%s//null-%x", parent->base.hname, uniq); |
| |
| profile = aa_alloc_profile(name); |
| kfree(name); |
| if (!profile) |
| goto fail; |
| |
| profile->mode = APPARMOR_COMPLAIN; |
| profile->flags = PFLAG_NULL; |
| if (hat) |
| profile->flags |= PFLAG_HAT; |
| |
| /* released on free_profile */ |
| rcu_assign_pointer(profile->parent, aa_get_profile(parent)); |
| profile->ns = aa_get_namespace(parent->ns); |
| |
| mutex_lock(&profile->ns->lock); |
| __list_add_profile(&parent->base.profiles, profile); |
| mutex_unlock(&profile->ns->lock); |
| |
| /* refcount released by caller */ |
| return profile; |
| |
| fail: |
| 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_namespace *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; |
| } |
| |
| /** |
| * __lookup_profile - lookup the profile matching @hname |
| * @base: base list to start looking up profile name from (NOT NULL) |
| * @hname: hierarchical profile name (NOT NULL) |
| * |
| * 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 *__lookup_profile(struct aa_policy *base, |
| const char *hname) |
| { |
| struct aa_profile *profile = NULL; |
| char *split; |
| |
| for (split = strstr(hname, "//"); split;) { |
| profile = __strn_find_child(&base->profiles, hname, |
| split - hname); |
| if (!profile) |
| return NULL; |
| |
| base = &profile->base; |
| hname = split + 2; |
| split = strstr(hname, "//"); |
| } |
| |
| profile = __find_child(&base->profiles, hname); |
| |
| return profile; |
| } |
| |
| /** |
| * 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) |
| * |
| * Returns: refcounted profile or NULL if not found |
| */ |
| struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname) |
| { |
| struct aa_profile *profile; |
| |
| rcu_read_lock(); |
| do { |
| profile = __lookup_profile(&ns->base, hname); |
| } while (profile && !aa_get_profile_not0(profile)); |
| rcu_read_unlock(); |
| |
| /* the unconfined profile is not in the regular profile list */ |
| if (!profile && strcmp(hname, "unconfined") == 0) |
| profile = aa_get_newest_profile(ns->unconfined); |
| |
| /* refcount released by caller */ |
| 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; |
| } |
| |
| /** |
| * aa_audit_policy - Do auditing of policy changes |
| * @op: policy operation being performed |
| * @gfp: memory allocation flags |
| * @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(int op, gfp_t gfp, const char *name, const char *info, |
| int error) |
| { |
| struct common_audit_data sa; |
| struct apparmor_audit_data aad = {0,}; |
| sa.type = LSM_AUDIT_DATA_NONE; |
| sa.aad = &aad; |
| aad.op = op; |
| aad.name = name; |
| aad.info = info; |
| aad.error = error; |
| |
| return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp, |
| &sa, NULL); |
| } |
| |
| bool policy_view_capable(void) |
| { |
| struct user_namespace *user_ns = current_user_ns(); |
| bool response = false; |
| |
| if (ns_capable(user_ns, CAP_MAC_ADMIN)) |
| response = true; |
| |
| return response; |
| } |
| |
| bool policy_admin_capable(void) |
| { |
| return policy_view_capable() && !aa_g_lock_policy; |
| } |
| |
| /** |
| * aa_may_manage_policy - can the current task manage policy |
| * @op: the policy manipulation operation being done |
| * |
| * Returns: true if the task is allowed to manipulate policy |
| */ |
| bool aa_may_manage_policy(int op) |
| { |
| /* check if loading policy is locked out */ |
| if (aa_g_lock_policy) { |
| audit_policy(op, GFP_KERNEL, NULL, "policy_locked", -EACCES); |
| return 0; |
| } |
| |
| if (!policy_admin_capable()) { |
| audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static struct aa_profile *__list_lookup_parent(struct list_head *lh, |
| struct aa_profile *profile) |
| { |
| const char *base = hname_tail(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_replacedby: transfer @old->replacedby 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_replacedby) |
| { |
| 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_replacedby); |
| 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_replacedby(old, new); |
| if (share_replacedby) { |
| aa_put_replacedby(new->replacedby); |
| new->replacedby = aa_get_replacedby(old->replacedby); |
| } else if (!rcu_access_pointer(new->replacedby->profile)) |
| /* aafs interface uses replacedby */ |
| rcu_assign_pointer(new->replacedby->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_namespace *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 |
| * @udata: serialized data stream (NOT NULL) |
| * @size: size of the serialized data stream |
| * @noreplace: true if only doing addition, no replacement allowed |
| * |
| * unpack and replace a profile on the profile list and uses of that profile |
| * by any aa_task_cxt. 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(void *udata, size_t size, bool noreplace) |
| { |
| const char *ns_name, *info = NULL; |
| struct aa_namespace *ns = NULL; |
| struct aa_load_ent *ent, *tmp; |
| int op = OP_PROF_REPL; |
| ssize_t error; |
| LIST_HEAD(lh); |
| |
| /* released below */ |
| error = aa_unpack(udata, size, &lh, &ns_name); |
| if (error) |
| goto out; |
| |
| /* released below */ |
| ns = aa_prepare_namespace(ns_name); |
| if (!ns) { |
| error = audit_policy(op, GFP_KERNEL, ns_name, |
| "failed to prepare namespace", -ENOMEM); |
| goto free; |
| } |
| |
| mutex_lock(&ns->lock); |
| /* setup parent and ns info */ |
| list_for_each_entry(ent, &lh, list) { |
| struct aa_policy *policy; |
| 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_namespace(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(op, GFP_ATOMIC, ent->new->base.hname, NULL, error); |
| |
| if (ent->old) { |
| __replace_profile(ent->old, ent->new, 1); |
| if (ent->rename) { |
| /* aafs interface uses replacedby */ |
| struct aa_replacedby *r = ent->new->replacedby; |
| rcu_assign_pointer(r->profile, |
| aa_get_profile(ent->new)); |
| __replace_profile(ent->rename, ent->new, 0); |
| } |
| } else if (ent->rename) { |
| /* aafs interface uses replacedby */ |
| rcu_assign_pointer(ent->new->replacedby->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 replacedby */ |
| rcu_assign_pointer(ent->new->replacedby->profile, |
| aa_get_profile(ent->new)); |
| __list_add_profile(&newest->base.profiles, ent->new); |
| aa_put_profile(newest); |
| } else { |
| /* aafs interface uses replacedby */ |
| rcu_assign_pointer(ent->new->replacedby->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_namespace(ns); |
| |
| if (error) |
| return error; |
| return size; |
| |
| fail_lock: |
| mutex_unlock(&ns->lock); |
| |
| /* audit cause of failure */ |
| op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL; |
| audit_policy(op, GFP_KERNEL, ent->new->base.hname, 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 = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL; |
| audit_policy(op, GFP_KERNEL, tmp->new->base.hname, info, error); |
| } |
| free: |
| 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 |
| * @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(char *fqname, size_t size) |
| { |
| struct aa_namespace *root, *ns = NULL; |
| struct aa_profile *profile = NULL; |
| const char *name = fqname, *info = NULL; |
| ssize_t error = 0; |
| |
| if (*fqname == 0) { |
| info = "no profile specified"; |
| error = -ENOENT; |
| goto fail; |
| } |
| |
| root = aa_current_profile()->ns; |
| |
| if (fqname[0] == ':') { |
| char *ns_name; |
| name = aa_split_fqname(fqname, &ns_name); |
| /* released below */ |
| ns = aa_find_namespace(root, ns_name); |
| if (!ns) { |
| info = "namespace does not exist"; |
| error = -ENOENT; |
| goto fail; |
| } |
| } else |
| /* released below */ |
| ns = aa_get_namespace(root); |
| |
| if (!name) { |
| /* remove namespace - can only happen if fqname[0] == ':' */ |
| mutex_lock(&ns->parent->lock); |
| __remove_namespace(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(OP_PROF_RM, GFP_KERNEL, name, info, error); |
| aa_put_namespace(ns); |
| aa_put_profile(profile); |
| return size; |
| |
| fail_ns_lock: |
| mutex_unlock(&ns->lock); |
| aa_put_namespace(ns); |
| |
| fail: |
| (void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error); |
| return error; |
| } |