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1203 lines
33 KiB
1203 lines
33 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* AppArmor security module |
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* |
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* This file contains AppArmor policy manipulation functions |
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* |
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* Copyright (C) 1998-2008 Novell/SUSE |
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* Copyright 2009-2010 Canonical Ltd. |
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* |
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* AppArmor policy is based around profiles, which contain the rules a |
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* task is confined by. Every task in the system has a profile attached |
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* to it determined either by matching "unconfined" tasks against the |
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* visible set of profiles or by following a profiles attachment rules. |
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* |
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* Each profile exists in a profile namespace which is a container of |
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* visible profiles. Each namespace contains a special "unconfined" profile, |
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* which doesn't enforce any confinement on a task beyond DAC. |
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* |
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* Namespace and profile names can be written together in either |
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* of two syntaxes. |
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* :namespace:profile - used by kernel interfaces for easy detection |
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* namespace://profile - used by policy |
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* |
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* Profile names can not start with : or @ or ^ and may not contain \0 |
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* |
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* Reserved profile names |
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* unconfined - special automatically generated unconfined profile |
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* inherit - special name to indicate profile inheritance |
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* null-XXXX-YYYY - special automatically generated learning profiles |
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* |
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* Namespace names may not start with / or @ and may not contain \0 or : |
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* Reserved namespace names |
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* user-XXXX - user defined profiles |
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* |
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* a // in a profile or namespace name indicates a hierarchical name with the |
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* name before the // being the parent and the name after the child. |
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* |
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* Profile and namespace hierarchies serve two different but similar purposes. |
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* The namespace contains the set of visible profiles that are considered |
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* for attachment. The hierarchy of namespaces allows for virtualizing |
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* the namespace so that for example a chroot can have its own set of profiles |
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* which may define some local user namespaces. |
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* The profile hierarchy severs two distinct purposes, |
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* - it allows for sub profiles or hats, which allows an application to run |
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* subprograms under its own profile with different restriction than it |
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* self, and not have it use the system profile. |
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* eg. if a mail program starts an editor, the policy might make the |
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* restrictions tighter on the editor tighter than the mail program, |
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* and definitely different than general editor restrictions |
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* - it allows for binary hierarchy of profiles, so that execution history |
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* is preserved. This feature isn't exploited by AppArmor reference policy |
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* but is allowed. NOTE: this is currently suboptimal because profile |
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* aliasing is not currently implemented so that a profile for each |
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* level must be defined. |
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* eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started |
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* from /bin/bash |
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* |
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* A profile or namespace name that can contain one or more // separators |
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* is referred to as an hname (hierarchical). |
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* eg. /bin/bash//bin/ls |
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* |
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* An fqname is a name that may contain both namespace and profile hnames. |
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* eg. :ns:/bin/bash//bin/ls |
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* |
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* NOTES: |
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* - locking of profile lists is currently fairly coarse. All profile |
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* lists within a namespace use the namespace lock. |
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* FIXME: move profile lists to using rcu_lists |
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*/ |
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|
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#include <linux/slab.h> |
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#include <linux/spinlock.h> |
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#include <linux/string.h> |
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#include <linux/cred.h> |
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#include <linux/rculist.h> |
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#include <linux/user_namespace.h> |
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|
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#include "include/apparmor.h" |
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#include "include/capability.h" |
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#include "include/cred.h" |
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#include "include/file.h" |
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#include "include/ipc.h" |
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#include "include/match.h" |
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#include "include/path.h" |
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#include "include/policy.h" |
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#include "include/policy_ns.h" |
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#include "include/policy_unpack.h" |
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#include "include/resource.h" |
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|
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int unprivileged_userns_apparmor_policy = 1; |
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|
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const char *const aa_profile_mode_names[] = { |
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"enforce", |
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"complain", |
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"kill", |
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"unconfined", |
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}; |
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|
|
|
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/** |
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* __add_profile - add a profiles to list and label tree |
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* @list: list to add it to (NOT NULL) |
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* @profile: the profile to add (NOT NULL) |
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* |
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* refcount @profile, should be put by __list_remove_profile |
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* |
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* Requires: namespace lock be held, or list not be shared |
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*/ |
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static void __add_profile(struct list_head *list, struct aa_profile *profile) |
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{ |
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struct aa_label *l; |
|
|
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AA_BUG(!list); |
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AA_BUG(!profile); |
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AA_BUG(!profile->ns); |
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AA_BUG(!mutex_is_locked(&profile->ns->lock)); |
|
|
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list_add_rcu(&profile->base.list, list); |
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/* get list reference */ |
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aa_get_profile(profile); |
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l = aa_label_insert(&profile->ns->labels, &profile->label); |
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AA_BUG(l != &profile->label); |
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aa_put_label(l); |
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} |
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|
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/** |
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* __list_remove_profile - remove a profile from the list it is on |
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* @profile: the profile to remove (NOT NULL) |
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* |
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* remove a profile from the list, warning generally removal should |
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* be done with __replace_profile as most profile removals are |
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* replacements to the unconfined profile. |
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* |
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* put @profile list refcount |
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* |
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* Requires: namespace lock be held, or list not have been live |
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*/ |
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static void __list_remove_profile(struct aa_profile *profile) |
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{ |
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AA_BUG(!profile); |
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AA_BUG(!profile->ns); |
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AA_BUG(!mutex_is_locked(&profile->ns->lock)); |
|
|
|
list_del_rcu(&profile->base.list); |
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aa_put_profile(profile); |
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} |
|
|
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/** |
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* __remove_profile - remove old profile, and children |
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* @profile: profile to be replaced (NOT NULL) |
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* |
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* Requires: namespace list lock be held, or list not be shared |
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*/ |
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static void __remove_profile(struct aa_profile *profile) |
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{ |
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AA_BUG(!profile); |
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AA_BUG(!profile->ns); |
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AA_BUG(!mutex_is_locked(&profile->ns->lock)); |
|
|
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/* release any children lists first */ |
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__aa_profile_list_release(&profile->base.profiles); |
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/* released by free_profile */ |
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aa_label_remove(&profile->label); |
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__aafs_profile_rmdir(profile); |
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__list_remove_profile(profile); |
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} |
|
|
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/** |
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* __aa_profile_list_release - remove all profiles on the list and put refs |
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* @head: list of profiles (NOT NULL) |
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* |
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* Requires: namespace lock be held |
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*/ |
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void __aa_profile_list_release(struct list_head *head) |
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{ |
|
struct aa_profile *profile, *tmp; |
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list_for_each_entry_safe(profile, tmp, head, base.list) |
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__remove_profile(profile); |
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} |
|
|
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/** |
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* aa_free_data - free a data blob |
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* @ptr: data to free |
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* @arg: unused |
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*/ |
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static void aa_free_data(void *ptr, void *arg) |
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{ |
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struct aa_data *data = ptr; |
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|
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kfree_sensitive(data->data); |
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kfree_sensitive(data->key); |
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kfree_sensitive(data); |
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} |
|
|
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/** |
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* aa_free_profile - free a profile |
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* @profile: the profile to free (MAYBE NULL) |
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* |
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* Free a profile, its hats and null_profile. All references to the profile, |
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* its hats and null_profile must have been put. |
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* |
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* If the profile was referenced from a task context, free_profile() will |
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* be called from an rcu callback routine, so we must not sleep here. |
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*/ |
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void aa_free_profile(struct aa_profile *profile) |
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{ |
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struct rhashtable *rht; |
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int i; |
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|
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AA_DEBUG("%s(%p)\n", __func__, profile); |
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|
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if (!profile) |
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return; |
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|
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/* free children profiles */ |
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aa_policy_destroy(&profile->base); |
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aa_put_profile(rcu_access_pointer(profile->parent)); |
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|
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aa_put_ns(profile->ns); |
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kfree_sensitive(profile->rename); |
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|
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aa_free_file_rules(&profile->file); |
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aa_free_cap_rules(&profile->caps); |
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aa_free_rlimit_rules(&profile->rlimits); |
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|
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for (i = 0; i < profile->xattr_count; i++) |
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kfree_sensitive(profile->xattrs[i]); |
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kfree_sensitive(profile->xattrs); |
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for (i = 0; i < profile->secmark_count; i++) |
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kfree_sensitive(profile->secmark[i].label); |
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kfree_sensitive(profile->secmark); |
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kfree_sensitive(profile->dirname); |
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aa_put_dfa(profile->xmatch); |
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aa_put_dfa(profile->policy.dfa); |
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|
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if (profile->data) { |
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rht = profile->data; |
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profile->data = NULL; |
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rhashtable_free_and_destroy(rht, aa_free_data, NULL); |
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kfree_sensitive(rht); |
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} |
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|
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kfree_sensitive(profile->hash); |
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aa_put_loaddata(profile->rawdata); |
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aa_label_destroy(&profile->label); |
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|
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kfree_sensitive(profile); |
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} |
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|
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/** |
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* aa_alloc_profile - allocate, initialize and return a new profile |
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* @hname: name of the profile (NOT NULL) |
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* @gfp: allocation type |
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* |
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* Returns: refcount profile or NULL on failure |
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*/ |
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struct aa_profile *aa_alloc_profile(const char *hname, struct aa_proxy *proxy, |
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gfp_t gfp) |
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{ |
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struct aa_profile *profile; |
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|
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/* freed by free_profile - usually through aa_put_profile */ |
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profile = kzalloc(struct_size(profile, label.vec, 2), gfp); |
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if (!profile) |
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return NULL; |
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|
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if (!aa_policy_init(&profile->base, NULL, hname, gfp)) |
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goto fail; |
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if (!aa_label_init(&profile->label, 1, gfp)) |
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goto fail; |
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|
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/* update being set needed by fs interface */ |
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if (!proxy) { |
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proxy = aa_alloc_proxy(&profile->label, gfp); |
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if (!proxy) |
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goto fail; |
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} else |
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aa_get_proxy(proxy); |
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profile->label.proxy = proxy; |
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|
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profile->label.hname = profile->base.hname; |
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profile->label.flags |= FLAG_PROFILE; |
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profile->label.vec[0] = profile; |
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|
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/* refcount released by caller */ |
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return profile; |
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|
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fail: |
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aa_free_profile(profile); |
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|
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return NULL; |
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} |
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|
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/* TODO: profile accounting - setup in remove */ |
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|
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/** |
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* __strn_find_child - find a profile on @head list using substring of @name |
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* @head: list to search (NOT NULL) |
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* @name: name of profile (NOT NULL) |
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* @len: length of @name substring to match |
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* |
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* Requires: rcu_read_lock be held |
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* |
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* Returns: unrefcounted profile ptr, or NULL if not found |
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*/ |
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static struct aa_profile *__strn_find_child(struct list_head *head, |
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const char *name, int len) |
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{ |
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return (struct aa_profile *)__policy_strn_find(head, name, len); |
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} |
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|
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/** |
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* __find_child - find a profile on @head list with a name matching @name |
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* @head: list to search (NOT NULL) |
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* @name: name of profile (NOT NULL) |
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* |
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* Requires: rcu_read_lock be held |
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* |
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* Returns: unrefcounted profile ptr, or NULL if not found |
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*/ |
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static struct aa_profile *__find_child(struct list_head *head, const char *name) |
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{ |
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return __strn_find_child(head, name, strlen(name)); |
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} |
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|
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/** |
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* aa_find_child - find a profile by @name in @parent |
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* @parent: profile to search (NOT NULL) |
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* @name: profile name to search for (NOT NULL) |
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* |
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* Returns: a refcounted profile or NULL if not found |
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*/ |
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struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name) |
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{ |
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struct aa_profile *profile; |
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|
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rcu_read_lock(); |
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do { |
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profile = __find_child(&parent->base.profiles, name); |
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} while (profile && !aa_get_profile_not0(profile)); |
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rcu_read_unlock(); |
|
|
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/* refcount released by caller */ |
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return profile; |
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} |
|
|
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/** |
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* __lookup_parent - lookup the parent of a profile of name @hname |
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* @ns: namespace to lookup profile in (NOT NULL) |
|
* @hname: hierarchical profile name to find parent of (NOT NULL) |
|
* |
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* Lookups up the parent of a fully qualified profile name, the profile |
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* that matches hname does not need to exist, in general this |
|
* is used to load a new profile. |
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* |
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* Requires: rcu_read_lock be held |
|
* |
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* Returns: unrefcounted policy or NULL if not found |
|
*/ |
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static struct aa_policy *__lookup_parent(struct aa_ns *ns, |
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const char *hname) |
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{ |
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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_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; |
|
} |
|
|
|
/** |
|
* 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 *p, *profile; |
|
const char *bname; |
|
char *name = NULL; |
|
|
|
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 */ |
|
bname = basename(name); |
|
profile = aa_find_child(parent, bname); |
|
if (profile) |
|
goto out; |
|
|
|
profile = aa_alloc_profile(name, NULL, gfp); |
|
if (!profile) |
|
goto fail; |
|
|
|
profile->mode = APPARMOR_COMPLAIN; |
|
profile->label.flags |= FLAG_NULL; |
|
if (hat) |
|
profile->label.flags |= FLAG_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_nested(&profile->ns->lock, profile->ns->level); |
|
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); |
|
} |
|
mutex_unlock(&profile->ns->lock); |
|
|
|
/* refcount released by caller */ |
|
out: |
|
kfree(name); |
|
|
|
return profile; |
|
|
|
fail: |
|
kfree(name); |
|
aa_free_profile(profile); |
|
return NULL; |
|
} |
|
|
|
/** |
|
* 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; |
|
|
|
if (aad(sa)->iface.ns) { |
|
audit_log_format(ab, " ns="); |
|
audit_log_untrustedstring(ab, aad(sa)->iface.ns); |
|
} |
|
} |
|
|
|
/** |
|
* audit_policy - Do auditing of policy changes |
|
* @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 *label, const char *op, |
|
const char *ns_name, const char *name, |
|
const char *info, int error) |
|
{ |
|
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op); |
|
|
|
aad(&sa)->iface.ns = ns_name; |
|
aad(&sa)->name = name; |
|
aad(&sa)->info = info; |
|
aad(&sa)->error = error; |
|
aad(&sa)->label = label; |
|
|
|
aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, audit_cb); |
|
|
|
return error; |
|
} |
|
|
|
/* don't call out to other LSMs in the stack for apparmor policy admin |
|
* permissions |
|
*/ |
|
static int policy_ns_capable(struct aa_label *label, |
|
struct user_namespace *userns, int cap) |
|
{ |
|
int err; |
|
|
|
/* check for MAC_ADMIN cap in cred */ |
|
err = cap_capable(current_cred(), userns, cap, CAP_OPT_NONE); |
|
if (!err) |
|
err = aa_capable(label, cap, CAP_OPT_NONE); |
|
|
|
return err; |
|
} |
|
|
|
/** |
|
* aa_policy_view_capable - check if viewing policy in at @ns is allowed |
|
* 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(struct aa_label *label, struct aa_ns *ns) |
|
{ |
|
struct user_namespace *user_ns = current_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(struct aa_label *label, struct aa_ns *ns) |
|
{ |
|
struct user_namespace *user_ns = current_user_ns(); |
|
bool capable = policy_ns_capable(label, user_ns, CAP_MAC_ADMIN) == 0; |
|
|
|
AA_DEBUG("cap_mac_admin? %d\n", capable); |
|
AA_DEBUG("policy locked? %d\n", aa_g_lock_policy); |
|
|
|
return aa_policy_view_capable(label, ns) && capable && |
|
!aa_g_lock_policy; |
|
} |
|
|
|
bool aa_current_policy_view_capable(struct aa_ns *ns) |
|
{ |
|
struct aa_label *label; |
|
bool res; |
|
|
|
label = __begin_current_label_crit_section(); |
|
res = aa_policy_view_capable(label, ns); |
|
__end_current_label_crit_section(label); |
|
|
|
return res; |
|
} |
|
|
|
bool aa_current_policy_admin_capable(struct aa_ns *ns) |
|
{ |
|
struct aa_label *label; |
|
bool res; |
|
|
|
label = __begin_current_label_crit_section(); |
|
res = aa_policy_admin_capable(label, ns); |
|
__end_current_label_crit_section(label); |
|
|
|
return res; |
|
} |
|
|
|
/** |
|
* aa_may_manage_policy - can the current task manage policy |
|
* @label: label 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_label *label, struct aa_ns *ns, 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 (!aa_policy_admin_capable(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) |
|
* @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) |
|
{ |
|
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) |
|
* |
|
* 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) |
|
{ |
|
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_loaddata(udata); |
|
/* 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(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 */ |
|
list_for_each_entry(rawdata_ent, &ns->rawdata_list, list) { |
|
if (aa_rawdata_eq(rawdata_ent, udata)) { |
|
struct aa_loaddata *tmp; |
|
|
|
tmp = __aa_get_loaddata(rawdata_ent); |
|
/* check we didn't fail the race */ |
|
if (tmp) { |
|
aa_put_loaddata(udata); |
|
udata = tmp; |
|
break; |
|
} |
|
} |
|
} |
|
/* 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, |
|
!(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 */ |
|
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 */ |
|
if (!udata->dents[AAFS_LOADDATA_DIR]) { |
|
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); |
|
__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) { |
|
/* 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; |
|
} |
|
|
|
/* |
|
* 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); |
|
} 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); |
|
aa_put_loaddata(udata); |
|
kfree(ns_name); |
|
|
|
if (error) |
|
return error; |
|
return udata->size; |
|
|
|
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->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; |
|
}
|
|
|