2 * AppArmor security module
4 * This file contains AppArmor policy manipulation functions
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2017 Canonical Ltd.
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
14 * AppArmor policy namespaces, allow for different sets of policies
15 * to be loaded for tasks within the namespace.
18 #include <linux/list.h>
19 #include <linux/mutex.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
23 #include "include/apparmor.h"
24 #include "include/context.h"
25 #include "include/policy_ns.h"
26 #include "include/label.h"
27 #include "include/policy.h"
29 /* root profile namespace */
30 struct aa_ns *root_ns;
31 const char *aa_hidden_ns_name = "---";
34 * aa_ns_visible - test if @view is visible from @curr
35 * @curr: namespace to treat as the parent (NOT NULL)
36 * @view: namespace to test if visible from @curr (NOT NULL)
37 * @subns: whether view of a subns is allowed
39 * Returns: true if @view is visible from @curr else false
41 bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns)
49 for ( ; view; view = view->parent) {
50 if (view->parent == curr)
58 * aa_na_name - Find the ns name to display for @view from @curr
59 * @curr - current namespace (NOT NULL)
60 * @view - namespace attempting to view (NOT NULL)
61 * @subns - are subns visible
63 * Returns: name of @view visible from @curr
65 const char *aa_ns_name(struct aa_ns *curr, struct aa_ns *view, bool subns)
67 /* if view == curr then the namespace name isn't displayed */
71 if (aa_ns_visible(curr, view, subns)) {
72 /* at this point if a ns is visible it is in a view ns
73 * thus the curr ns.hname is a prefix of its name.
74 * Only output the virtualized portion of the name
75 * Add + 2 to skip over // separating curr hname prefix
76 * from the visible tail of the views hname
78 return view->base.hname + strlen(curr->base.hname) + 2;
81 return aa_hidden_ns_name;
85 * alloc_ns - allocate, initialize and return a new namespace
86 * @prefix: parent namespace name (MAYBE NULL)
87 * @name: a preallocated name (NOT NULL)
89 * Returns: refcounted namespace or NULL on failure.
91 static struct aa_ns *alloc_ns(const char *prefix, const char *name)
95 ns = kzalloc(sizeof(*ns), GFP_KERNEL);
96 AA_DEBUG("%s(%p)\n", __func__, ns);
99 if (!aa_policy_init(&ns->base, prefix, name, GFP_KERNEL))
102 INIT_LIST_HEAD(&ns->sub_ns);
103 INIT_LIST_HEAD(&ns->rawdata_list);
104 mutex_init(&ns->lock);
105 init_waitqueue_head(&ns->wait);
107 /* released by aa_free_ns() */
108 ns->unconfined = aa_alloc_profile("unconfined", NULL, GFP_KERNEL);
110 goto fail_unconfined;
112 ns->unconfined->label.flags |= FLAG_IX_ON_NAME_ERROR |
113 FLAG_IMMUTIBLE | FLAG_NS_COUNT | FLAG_UNCONFINED;
114 ns->unconfined->mode = APPARMOR_UNCONFINED;
116 /* ns and ns->unconfined share ns->unconfined refcount */
117 ns->unconfined->ns = ns;
119 atomic_set(&ns->uniq_null, 0);
121 aa_labelset_init(&ns->labels);
126 kzfree(ns->base.hname);
133 * aa_free_ns - free a profile namespace
134 * @ns: the namespace to free (MAYBE NULL)
136 * Requires: All references to the namespace must have been put, if the
137 * namespace was referenced by a profile confining a task,
139 void aa_free_ns(struct aa_ns *ns)
144 aa_policy_destroy(&ns->base);
145 aa_labelset_destroy(&ns->labels);
146 aa_put_ns(ns->parent);
148 ns->unconfined->ns = NULL;
149 aa_free_profile(ns->unconfined);
154 * aa_findn_ns - look up a profile namespace on the namespace list
155 * @root: namespace to search in (NOT NULL)
156 * @name: name of namespace to find (NOT NULL)
157 * @n: length of @name
159 * Returns: a refcounted namespace on the list, or NULL if no namespace
160 * called @name exists.
162 * refcount released by caller
164 struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n)
166 struct aa_ns *ns = NULL;
169 ns = aa_get_ns(__aa_findn_ns(&root->sub_ns, name, n));
176 * aa_find_ns - look up a profile namespace on the namespace list
177 * @root: namespace to search in (NOT NULL)
178 * @name: name of namespace to find (NOT NULL)
180 * Returns: a refcounted namespace on the list, or NULL if no namespace
181 * called @name exists.
183 * refcount released by caller
185 struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name)
187 return aa_findn_ns(root, name, strlen(name));
191 * __aa_lookupn_ns - lookup the namespace matching @hname
192 * @base: base list to start looking up profile name from (NOT NULL)
193 * @hname: hierarchical ns name (NOT NULL)
194 * @n: length of @hname
196 * Requires: rcu_read_lock be held
198 * Returns: unrefcounted ns pointer or NULL if not found
200 * Do a relative name lookup, recursing through profile tree.
202 struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n)
204 struct aa_ns *ns = view;
207 for (split = strnstr(hname, "//", n); split;
208 split = strnstr(hname, "//", n)) {
209 ns = __aa_findn_ns(&ns->sub_ns, hname, split - hname);
213 n -= split + 2 - hname;
218 return __aa_findn_ns(&ns->sub_ns, hname, n);
223 * aa_lookupn_ns - look up a policy namespace relative to @view
224 * @view: namespace to search in (NOT NULL)
225 * @name: name of namespace to find (NOT NULL)
226 * @n: length of @name
228 * Returns: a refcounted namespace on the list, or NULL if no namespace
229 * called @name exists.
231 * refcount released by caller
233 struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n)
235 struct aa_ns *ns = NULL;
238 ns = aa_get_ns(__aa_lookupn_ns(view, name, n));
244 static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name,
252 AA_BUG(!mutex_is_locked(&parent->lock));
254 ns = alloc_ns(parent->base.hname, name);
257 mutex_lock(&ns->lock);
258 error = __aafs_ns_mkdir(ns, ns_subns_dir(parent), name, dir);
260 AA_ERROR("Failed to create interface for ns %s\n",
262 mutex_unlock(&ns->lock);
264 return ERR_PTR(error);
266 ns->parent = aa_get_ns(parent);
267 ns->level = parent->level + 1;
268 list_add_rcu(&ns->base.list, &parent->sub_ns);
271 mutex_unlock(&ns->lock);
277 * aa_create_ns - create an ns, fail if it already exists
278 * @parent: the parent of the namespace being created
279 * @name: the name of the namespace
280 * @dir: if not null the dir to put the ns entries in
282 * Returns: the a refcounted ns that has been add or an ERR_PTR
284 struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name,
289 AA_BUG(!mutex_is_locked(&parent->lock));
291 /* try and find the specified ns */
292 /* released by caller */
293 ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
295 ns = __aa_create_ns(parent, name, dir);
297 ns = ERR_PTR(-EEXIST);
304 * aa_prepare_ns - find an existing or create a new namespace of @name
305 * @parent: ns to treat as parent
306 * @name: the namespace to find or add (NOT NULL)
308 * Returns: refcounted namespace or PTR_ERR if failed to create one
310 struct aa_ns *aa_prepare_ns(struct aa_ns *parent, const char *name)
314 mutex_lock(&parent->lock);
315 /* try and find the specified ns and if it doesn't exist create it */
316 /* released by caller */
317 ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
319 ns = __aa_create_ns(parent, name, NULL);
320 mutex_unlock(&parent->lock);
326 static void __ns_list_release(struct list_head *head);
329 * destroy_ns - remove everything contained by @ns
330 * @ns: namespace to have it contents removed (NOT NULL)
332 static void destroy_ns(struct aa_ns *ns)
337 mutex_lock(&ns->lock);
338 /* release all profiles in this namespace */
339 __aa_profile_list_release(&ns->base.profiles);
341 /* release all sub namespaces */
342 __ns_list_release(&ns->sub_ns);
347 write_lock_irqsave(&ns->labels.lock, flags);
348 __aa_proxy_redirect(ns_unconfined(ns),
349 ns_unconfined(ns->parent));
350 write_unlock_irqrestore(&ns->labels.lock, flags);
353 mutex_unlock(&ns->lock);
357 * __aa_remove_ns - remove a namespace and all its children
358 * @ns: namespace to be removed (NOT NULL)
360 * Requires: ns->parent->lock be held and ns removed from parent.
362 void __aa_remove_ns(struct aa_ns *ns)
364 /* remove ns from namespace list */
365 list_del_rcu(&ns->base.list);
371 * __ns_list_release - remove all profile namespaces on the list put refs
372 * @head: list of profile namespaces (NOT NULL)
374 * Requires: namespace lock be held
376 static void __ns_list_release(struct list_head *head)
378 struct aa_ns *ns, *tmp;
380 list_for_each_entry_safe(ns, tmp, head, base.list)
386 * aa_alloc_root_ns - allocate the root profile namespace
388 * Returns: %0 on success else error
391 int __init aa_alloc_root_ns(void)
393 /* released by aa_free_root_ns - used as list ref*/
394 root_ns = alloc_ns(NULL, "root");
402 * aa_free_root_ns - free the root profile namespace
404 void __init aa_free_root_ns(void)
406 struct aa_ns *ns = root_ns;