1 // SPDX-License-Identifier: GPL-2.0-only
3 * AppArmor security module
5 * This file contains AppArmor policy manipulation functions
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2017 Canonical Ltd.
10 * AppArmor policy namespaces, allow for different sets of policies
11 * to be loaded for tasks within the namespace.
14 #include <linux/list.h>
15 #include <linux/mutex.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
19 #include "include/apparmor.h"
20 #include "include/cred.h"
21 #include "include/policy_ns.h"
22 #include "include/label.h"
23 #include "include/policy.h"
26 struct aa_label *kernel_t;
28 /* root profile namespace */
29 struct aa_ns *root_ns;
30 const char *aa_hidden_ns_name = "---";
33 * aa_ns_visible - test if @view is visible from @curr
34 * @curr: namespace to treat as the parent (NOT NULL)
35 * @view: namespace to test if visible from @curr (NOT NULL)
36 * @subns: whether view of a subns is allowed
38 * Returns: true if @view is visible from @curr else false
40 bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns)
48 for ( ; view; view = view->parent) {
49 if (view->parent == curr)
57 * aa_ns_name - Find the ns name to display for @view from @curr
58 * @curr: current namespace (NOT NULL)
59 * @view: namespace attempting to view (NOT NULL)
60 * @subns: are subns visible
62 * Returns: name of @view visible from @curr
64 const char *aa_ns_name(struct aa_ns *curr, struct aa_ns *view, bool subns)
66 /* if view == curr then the namespace name isn't displayed */
70 if (aa_ns_visible(curr, view, subns)) {
71 /* at this point if a ns is visible it is in a view ns
72 * thus the curr ns.hname is a prefix of its name.
73 * Only output the virtualized portion of the name
74 * Add + 2 to skip over // separating curr hname prefix
75 * from the visible tail of the views hname
77 return view->base.hname + strlen(curr->base.hname) + 2;
80 return aa_hidden_ns_name;
83 static struct aa_profile *alloc_unconfined(const char *name)
85 struct aa_profile *profile;
87 profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
91 profile->label.flags |= FLAG_IX_ON_NAME_ERROR |
92 FLAG_IMMUTIBLE | FLAG_NS_COUNT | FLAG_UNCONFINED;
93 profile->mode = APPARMOR_UNCONFINED;
94 profile->file.dfa = aa_get_dfa(nulldfa);
95 profile->policy.dfa = aa_get_dfa(nulldfa);
101 * alloc_ns - allocate, initialize and return a new namespace
102 * @prefix: parent namespace name (MAYBE NULL)
103 * @name: a preallocated name (NOT NULL)
105 * Returns: refcounted namespace or NULL on failure.
107 static struct aa_ns *alloc_ns(const char *prefix, const char *name)
111 ns = kzalloc(sizeof(*ns), GFP_KERNEL);
112 AA_DEBUG("%s(%p)\n", __func__, ns);
115 if (!aa_policy_init(&ns->base, prefix, name, GFP_KERNEL))
118 INIT_LIST_HEAD(&ns->sub_ns);
119 INIT_LIST_HEAD(&ns->rawdata_list);
120 mutex_init(&ns->lock);
121 init_waitqueue_head(&ns->wait);
123 /* released by aa_free_ns() */
124 ns->unconfined = alloc_unconfined("unconfined");
126 goto fail_unconfined;
127 /* ns and ns->unconfined share ns->unconfined refcount */
128 ns->unconfined->ns = ns;
130 atomic_set(&ns->uniq_null, 0);
132 aa_labelset_init(&ns->labels);
137 aa_policy_destroy(&ns->base);
144 * aa_free_ns - free a profile namespace
145 * @ns: the namespace to free (MAYBE NULL)
147 * Requires: All references to the namespace must have been put, if the
148 * namespace was referenced by a profile confining a task,
150 void aa_free_ns(struct aa_ns *ns)
155 aa_policy_destroy(&ns->base);
156 aa_labelset_destroy(&ns->labels);
157 aa_put_ns(ns->parent);
159 ns->unconfined->ns = NULL;
160 aa_free_profile(ns->unconfined);
165 * aa_findn_ns - look up a profile namespace on the namespace list
166 * @root: namespace to search in (NOT NULL)
167 * @name: name of namespace to find (NOT NULL)
168 * @n: length of @name
170 * Returns: a refcounted namespace on the list, or NULL if no namespace
171 * called @name exists.
173 * refcount released by caller
175 struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n)
177 struct aa_ns *ns = NULL;
180 ns = aa_get_ns(__aa_findn_ns(&root->sub_ns, name, n));
187 * aa_find_ns - look up a profile namespace on the namespace list
188 * @root: namespace to search in (NOT NULL)
189 * @name: name of namespace to find (NOT NULL)
191 * Returns: a refcounted namespace on the list, or NULL if no namespace
192 * called @name exists.
194 * refcount released by caller
196 struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name)
198 return aa_findn_ns(root, name, strlen(name));
202 * __aa_lookupn_ns - lookup the namespace matching @hname
203 * @view: namespace to search in (NOT NULL)
204 * @hname: hierarchical ns name (NOT NULL)
205 * @n: length of @hname
207 * Requires: rcu_read_lock be held
209 * Returns: unrefcounted ns pointer or NULL if not found
211 * Do a relative name lookup, recursing through profile tree.
213 struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n)
215 struct aa_ns *ns = view;
218 for (split = strnstr(hname, "//", n); split;
219 split = strnstr(hname, "//", n)) {
220 ns = __aa_findn_ns(&ns->sub_ns, hname, split - hname);
224 n -= split + 2 - hname;
229 return __aa_findn_ns(&ns->sub_ns, hname, n);
234 * aa_lookupn_ns - look up a policy namespace relative to @view
235 * @view: namespace to search in (NOT NULL)
236 * @name: name of namespace to find (NOT NULL)
237 * @n: length of @name
239 * Returns: a refcounted namespace on the list, or NULL if no namespace
240 * called @name exists.
242 * refcount released by caller
244 struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n)
246 struct aa_ns *ns = NULL;
249 ns = aa_get_ns(__aa_lookupn_ns(view, name, n));
255 static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name,
263 AA_BUG(!mutex_is_locked(&parent->lock));
265 ns = alloc_ns(parent->base.hname, name);
267 return ERR_PTR(-ENOMEM);
268 ns->level = parent->level + 1;
269 mutex_lock_nested(&ns->lock, ns->level);
270 error = __aafs_ns_mkdir(ns, ns_subns_dir(parent), name, dir);
272 AA_ERROR("Failed to create interface for ns %s\n",
274 mutex_unlock(&ns->lock);
276 return ERR_PTR(error);
278 ns->parent = aa_get_ns(parent);
279 list_add_rcu(&ns->base.list, &parent->sub_ns);
282 mutex_unlock(&ns->lock);
288 * __aa_find_or_create_ns - create an ns, fail if it already exists
289 * @parent: the parent of the namespace being created
290 * @name: the name of the namespace
291 * @dir: if not null the dir to put the ns entries in
293 * Returns: the a refcounted ns that has been add or an ERR_PTR
295 struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name,
300 AA_BUG(!mutex_is_locked(&parent->lock));
302 /* try and find the specified ns */
303 /* released by caller */
304 ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
306 ns = __aa_create_ns(parent, name, dir);
308 ns = ERR_PTR(-EEXIST);
315 * aa_prepare_ns - find an existing or create a new namespace of @name
316 * @parent: ns to treat as parent
317 * @name: the namespace to find or add (NOT NULL)
319 * Returns: refcounted namespace or PTR_ERR if failed to create one
321 struct aa_ns *aa_prepare_ns(struct aa_ns *parent, const char *name)
325 mutex_lock_nested(&parent->lock, parent->level);
326 /* try and find the specified ns and if it doesn't exist create it */
327 /* released by caller */
328 ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
330 ns = __aa_create_ns(parent, name, NULL);
331 mutex_unlock(&parent->lock);
337 static void __ns_list_release(struct list_head *head);
340 * destroy_ns - remove everything contained by @ns
341 * @ns: namespace to have it contents removed (NOT NULL)
343 static void destroy_ns(struct aa_ns *ns)
348 mutex_lock_nested(&ns->lock, ns->level);
349 /* release all profiles in this namespace */
350 __aa_profile_list_release(&ns->base.profiles);
352 /* release all sub namespaces */
353 __ns_list_release(&ns->sub_ns);
358 write_lock_irqsave(&ns->labels.lock, flags);
359 __aa_proxy_redirect(ns_unconfined(ns),
360 ns_unconfined(ns->parent));
361 write_unlock_irqrestore(&ns->labels.lock, flags);
364 mutex_unlock(&ns->lock);
368 * __aa_remove_ns - remove a namespace and all its children
369 * @ns: namespace to be removed (NOT NULL)
371 * Requires: ns->parent->lock be held and ns removed from parent.
373 void __aa_remove_ns(struct aa_ns *ns)
375 /* remove ns from namespace list */
376 list_del_rcu(&ns->base.list);
382 * __ns_list_release - remove all profile namespaces on the list put refs
383 * @head: list of profile namespaces (NOT NULL)
385 * Requires: namespace lock be held
387 static void __ns_list_release(struct list_head *head)
389 struct aa_ns *ns, *tmp;
391 list_for_each_entry_safe(ns, tmp, head, base.list)
397 * aa_alloc_root_ns - allocate the root profile namespace
399 * Returns: %0 on success else error
402 int __init aa_alloc_root_ns(void)
404 struct aa_profile *kernel_p;
406 /* released by aa_free_root_ns - used as list ref*/
407 root_ns = alloc_ns(NULL, "root");
411 kernel_p = alloc_unconfined("kernel_t");
417 kernel_t = &kernel_p->label;
418 root_ns->unconfined->ns = aa_get_ns(root_ns);
424 * aa_free_root_ns - free the root profile namespace
426 void __init aa_free_root_ns(void)
428 struct aa_ns *ns = root_ns;
432 aa_label_free(kernel_t);