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d61c57fde8
Embedded systems have limited space and don't need the introspection or checkpoint restore capability provided by exporting the raw profile binary data so make it so make it a config option. This will reduce run time memory use and also speed up policy loads. Signed-off-by: John Johansen <john.johansen@canonical.com>
1209 lines
33 KiB
C
1209 lines
33 KiB
C
// 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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#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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#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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int unprivileged_userns_apparmor_policy = 1;
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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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* __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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* __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));
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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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{
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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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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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AA_DEBUG("%s(%p)\n", __func__, profile);
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if (!profile)
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return;
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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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aa_put_ns(profile->ns);
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kfree_sensitive(profile->rename);
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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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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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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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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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kfree_sensitive(profile);
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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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/* 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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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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/* 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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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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/* refcount released by caller */
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return profile;
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fail:
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aa_free_profile(profile);
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return NULL;
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}
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/* TODO: profile accounting - setup in remove */
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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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* __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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* 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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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)
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* @hname: hierarchical profile name to find parent of (NOT NULL)
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*
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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
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* 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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*
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* Returns: unrefcounted policy or NULL if not found
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*/
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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;
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struct aa_profile *profile = NULL;
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char *split;
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policy = &ns->base;
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for (split = strstr(hname, "//"); split;) {
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profile = __strn_find_child(&policy->profiles, hname,
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split - hname);
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if (!profile)
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return NULL;
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policy = &profile->base;
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hname = split + 2;
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split = strstr(hname, "//");
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}
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if (!profile)
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return &ns->base;
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return &profile->base;
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}
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/**
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* __lookupn_profile - lookup the profile matching @hname
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* @base: base list to start looking up profile name from (NOT NULL)
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* @hname: hierarchical profile name (NOT NULL)
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* @n: length of @hname
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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 pointer or NULL if not found
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*
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* Do a relative name lookup, recursing through profile tree.
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*/
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static struct aa_profile *__lookupn_profile(struct aa_policy *base,
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const char *hname, size_t n)
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{
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struct aa_profile *profile = NULL;
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const char *split;
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for (split = strnstr(hname, "//", n); split;
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split = strnstr(hname, "//", n)) {
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profile = __strn_find_child(&base->profiles, hname,
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split - hname);
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if (!profile)
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return NULL;
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base = &profile->base;
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n -= split + 2 - hname;
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hname = split + 2;
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}
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if (n)
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return __strn_find_child(&base->profiles, hname, n);
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return NULL;
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}
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static struct aa_profile *__lookup_profile(struct aa_policy *base,
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const char *hname)
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{
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return __lookupn_profile(base, hname, strlen(hname));
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}
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/**
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* aa_lookupn_profile - find a profile by its full or partial name
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* @ns: the namespace to start from (NOT NULL)
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* @hname: name to do lookup on. Does not contain namespace prefix (NOT NULL)
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* @n: size of @hname
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*
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* Returns: refcounted profile or NULL if not found
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*/
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struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
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size_t n)
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{
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struct aa_profile *profile;
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rcu_read_lock();
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do {
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profile = __lookupn_profile(&ns->base, hname, n);
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} while (profile && !aa_get_profile_not0(profile));
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rcu_read_unlock();
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/* the unconfined profile is not in the regular profile list */
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if (!profile && strncmp(hname, "unconfined", n) == 0)
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profile = aa_get_newest_profile(ns->unconfined);
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/* refcount released by caller */
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return profile;
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}
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struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *hname)
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{
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return aa_lookupn_profile(ns, hname, strlen(hname));
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}
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struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
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const char *fqname, size_t n)
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{
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struct aa_profile *profile;
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struct aa_ns *ns;
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const char *name, *ns_name;
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size_t ns_len;
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name = aa_splitn_fqname(fqname, n, &ns_name, &ns_len);
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if (ns_name) {
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ns = aa_lookupn_ns(labels_ns(base), ns_name, ns_len);
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if (!ns)
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return NULL;
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} else
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ns = aa_get_ns(labels_ns(base));
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|
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if (name)
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profile = aa_lookupn_profile(ns, name, n - (name - fqname));
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else if (ns)
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/* default profile for ns, currently unconfined */
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profile = aa_get_newest_profile(ns->unconfined);
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else
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profile = NULL;
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aa_put_ns(ns);
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|
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return profile;
|
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}
|
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|
|
/**
|
|
* 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
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|
* @base: name to base the null profile off of
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* @gfp: type of allocation
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*
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* Find/Create a null- complain mode profile used in learning mode. The
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* name of the profile is unique and follows the format of parent//null-XXX.
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* where XXX is based on the @name or if that fails or is not supplied
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* a unique number
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*
|
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* null profiles are added to the profile list but the list does not
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* hold a count on them so that they are automatically released when
|
|
* not in use.
|
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*
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* Returns: new refcounted profile else NULL on failure
|
|
*/
|
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struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
|
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const char *base, gfp_t gfp)
|
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{
|
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struct aa_profile *p, *profile;
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const char *bname;
|
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char *name = NULL;
|
|
|
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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 */
|
|
if (!list_empty(&ns->rawdata_list)) {
|
|
list_for_each_entry(rawdata_ent, &ns->rawdata_list, list) {
|
|
if (aa_rawdata_eq(rawdata_ent, udata)) {
|
|
struct aa_loaddata *tmp;
|
|
|
|
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;
|
|
|
|
if (aa_g_export_binary)
|
|
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] && aa_g_export_binary) {
|
|
error = __aa_fs_create_rawdata(ns, udata);
|
|
if (error) {
|
|
info = "failed to create raw_data dir and files";
|
|
ent = NULL;
|
|
goto fail_lock;
|
|
}
|
|
}
|
|
list_for_each_entry(ent, &lh, list) {
|
|
if (!ent->old) {
|
|
struct dentry *parent;
|
|
if (rcu_access_pointer(ent->new->parent)) {
|
|
struct aa_profile *p;
|
|
p = aa_deref_parent(ent->new);
|
|
parent = prof_child_dir(p);
|
|
} else
|
|
parent = ns_subprofs_dir(ent->new->ns);
|
|
error = __aafs_profile_mkdir(ent->new, parent);
|
|
}
|
|
|
|
if (error) {
|
|
info = "failed to create";
|
|
goto fail_lock;
|
|
}
|
|
}
|
|
|
|
/* Done with checks that may fail - do actual replacement */
|
|
__aa_bump_ns_revision(ns);
|
|
if (aa_g_export_binary)
|
|
__aa_loaddata_update(udata, ns->revision);
|
|
list_for_each_entry_safe(ent, tmp, &lh, list) {
|
|
list_del_init(&ent->list);
|
|
op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;
|
|
|
|
if (ent->old && ent->old->rawdata == ent->new->rawdata &&
|
|
ent->new->rawdata) {
|
|
/* dedup actual profile replacement */
|
|
audit_policy(label, op, ns_name, ent->new->base.hname,
|
|
"same as current profile, skipping",
|
|
error);
|
|
/* break refcount cycle with proxy. */
|
|
aa_put_proxy(ent->new->label.proxy);
|
|
ent->new->label.proxy = NULL;
|
|
goto skip;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|