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_null(NULL, name, GFP_KERNEL);
91 profile->label.flags |= FLAG_IX_ON_NAME_ERROR |
92 FLAG_IMMUTIBLE | FLAG_NS_COUNT | FLAG_UNCONFINED;
93 profile->mode = APPARMOR_UNCONFINED;
99 * alloc_ns - allocate, initialize and return a new namespace
100 * @prefix: parent namespace name (MAYBE NULL)
101 * @name: a preallocated name (NOT NULL)
103 * Returns: refcounted namespace or NULL on failure.
105 static struct aa_ns *alloc_ns(const char *prefix, const char *name)
109 ns = kzalloc(sizeof(*ns), GFP_KERNEL);
110 AA_DEBUG("%s(%p)\n", __func__, ns);
113 if (!aa_policy_init(&ns->base, prefix, name, GFP_KERNEL))
116 INIT_LIST_HEAD(&ns->sub_ns);
117 INIT_LIST_HEAD(&ns->rawdata_list);
118 mutex_init(&ns->lock);
119 init_waitqueue_head(&ns->wait);
121 /* released by aa_free_ns() */
122 ns->unconfined = alloc_unconfined("unconfined");
124 goto fail_unconfined;
125 /* ns and ns->unconfined share ns->unconfined refcount */
126 ns->unconfined->ns = ns;
128 atomic_set(&ns->uniq_null, 0);
130 aa_labelset_init(&ns->labels);
135 aa_policy_destroy(&ns->base);
142 * aa_free_ns - free a profile namespace
143 * @ns: the namespace to free (MAYBE NULL)
145 * Requires: All references to the namespace must have been put, if the
146 * namespace was referenced by a profile confining a task,
148 void aa_free_ns(struct aa_ns *ns)
153 aa_policy_destroy(&ns->base);
154 aa_labelset_destroy(&ns->labels);
155 aa_put_ns(ns->parent);
157 ns->unconfined->ns = NULL;
158 aa_free_profile(ns->unconfined);
163 * aa_findn_ns - look up a profile namespace on the namespace list
164 * @root: namespace to search in (NOT NULL)
165 * @name: name of namespace to find (NOT NULL)
166 * @n: length of @name
168 * Returns: a refcounted namespace on the list, or NULL if no namespace
169 * called @name exists.
171 * refcount released by caller
173 struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n)
175 struct aa_ns *ns = NULL;
178 ns = aa_get_ns(__aa_findn_ns(&root->sub_ns, name, n));
185 * aa_find_ns - look up a profile namespace on the namespace list
186 * @root: namespace to search in (NOT NULL)
187 * @name: name of namespace to find (NOT NULL)
189 * Returns: a refcounted namespace on the list, or NULL if no namespace
190 * called @name exists.
192 * refcount released by caller
194 struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name)
196 return aa_findn_ns(root, name, strlen(name));
200 * __aa_lookupn_ns - lookup the namespace matching @hname
201 * @view: namespace to search in (NOT NULL)
202 * @hname: hierarchical ns name (NOT NULL)
203 * @n: length of @hname
205 * Requires: rcu_read_lock be held
207 * Returns: unrefcounted ns pointer or NULL if not found
209 * Do a relative name lookup, recursing through profile tree.
211 struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n)
213 struct aa_ns *ns = view;
216 for (split = strnstr(hname, "//", n); split;
217 split = strnstr(hname, "//", n)) {
218 ns = __aa_findn_ns(&ns->sub_ns, hname, split - hname);
222 n -= split + 2 - hname;
227 return __aa_findn_ns(&ns->sub_ns, hname, n);
232 * aa_lookupn_ns - look up a policy namespace relative to @view
233 * @view: namespace to search in (NOT NULL)
234 * @name: name of namespace to find (NOT NULL)
235 * @n: length of @name
237 * Returns: a refcounted namespace on the list, or NULL if no namespace
238 * called @name exists.
240 * refcount released by caller
242 struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n)
244 struct aa_ns *ns = NULL;
247 ns = aa_get_ns(__aa_lookupn_ns(view, name, n));
253 static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name,
261 AA_BUG(!mutex_is_locked(&parent->lock));
263 ns = alloc_ns(parent->base.hname, name);
265 return ERR_PTR(-ENOMEM);
266 ns->level = parent->level + 1;
267 mutex_lock_nested(&ns->lock, ns->level);
268 error = __aafs_ns_mkdir(ns, ns_subns_dir(parent), name, dir);
270 AA_ERROR("Failed to create interface for ns %s\n",
272 mutex_unlock(&ns->lock);
274 return ERR_PTR(error);
276 ns->parent = aa_get_ns(parent);
277 list_add_rcu(&ns->base.list, &parent->sub_ns);
280 mutex_unlock(&ns->lock);
286 * __aa_find_or_create_ns - create an ns, fail if it already exists
287 * @parent: the parent of the namespace being created
288 * @name: the name of the namespace
289 * @dir: if not null the dir to put the ns entries in
291 * Returns: the a refcounted ns that has been add or an ERR_PTR
293 struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name,
298 AA_BUG(!mutex_is_locked(&parent->lock));
300 /* try and find the specified ns */
301 /* released by caller */
302 ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
304 ns = __aa_create_ns(parent, name, dir);
306 ns = ERR_PTR(-EEXIST);
313 * aa_prepare_ns - find an existing or create a new namespace of @name
314 * @parent: ns to treat as parent
315 * @name: the namespace to find or add (NOT NULL)
317 * Returns: refcounted namespace or PTR_ERR if failed to create one
319 struct aa_ns *aa_prepare_ns(struct aa_ns *parent, const char *name)
323 mutex_lock_nested(&parent->lock, parent->level);
324 /* try and find the specified ns and if it doesn't exist create it */
325 /* released by caller */
326 ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
328 ns = __aa_create_ns(parent, name, NULL);
329 mutex_unlock(&parent->lock);
335 static void __ns_list_release(struct list_head *head);
338 * destroy_ns - remove everything contained by @ns
339 * @ns: namespace to have it contents removed (NOT NULL)
341 static void destroy_ns(struct aa_ns *ns)
346 mutex_lock_nested(&ns->lock, ns->level);
347 /* release all profiles in this namespace */
348 __aa_profile_list_release(&ns->base.profiles);
350 /* release all sub namespaces */
351 __ns_list_release(&ns->sub_ns);
356 write_lock_irqsave(&ns->labels.lock, flags);
357 __aa_proxy_redirect(ns_unconfined(ns),
358 ns_unconfined(ns->parent));
359 write_unlock_irqrestore(&ns->labels.lock, flags);
362 mutex_unlock(&ns->lock);
366 * __aa_remove_ns - remove a namespace and all its children
367 * @ns: namespace to be removed (NOT NULL)
369 * Requires: ns->parent->lock be held and ns removed from parent.
371 void __aa_remove_ns(struct aa_ns *ns)
373 /* remove ns from namespace list */
374 list_del_rcu(&ns->base.list);
380 * __ns_list_release - remove all profile namespaces on the list put refs
381 * @head: list of profile namespaces (NOT NULL)
383 * Requires: namespace lock be held
385 static void __ns_list_release(struct list_head *head)
387 struct aa_ns *ns, *tmp;
389 list_for_each_entry_safe(ns, tmp, head, base.list)
395 * aa_alloc_root_ns - allocate the root profile namespace
397 * Returns: %0 on success else error
400 int __init aa_alloc_root_ns(void)
402 struct aa_profile *kernel_p;
404 /* released by aa_free_root_ns - used as list ref*/
405 root_ns = alloc_ns(NULL, "root");
409 kernel_p = alloc_unconfined("kernel_t");
415 kernel_t = &kernel_p->label;
416 root_ns->unconfined->ns = aa_get_ns(root_ns);
422 * aa_free_root_ns - free the root profile namespace
424 void __init aa_free_root_ns(void)
426 struct aa_ns *ns = root_ns;
430 aa_label_free(kernel_t);