~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/security/apparmor/policy_ns.c

Version: ~ [ linux-5.12-rc7 ] ~ [ linux-5.11.13 ] ~ [ linux-5.10.29 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.111 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.186 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.230 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.266 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.266 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * AppArmor security module
  3  *
  4  * This file contains AppArmor policy manipulation functions
  5  *
  6  * Copyright (C) 1998-2008 Novell/SUSE
  7  * Copyright 2009-2017 Canonical Ltd.
  8  *
  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
 12  * License.
 13  *
 14  * AppArmor policy namespaces, allow for different sets of policies
 15  * to be loaded for tasks within the namespace.
 16  */
 17 
 18 #include <linux/list.h>
 19 #include <linux/mutex.h>
 20 #include <linux/slab.h>
 21 #include <linux/string.h>
 22 
 23 #include "include/apparmor.h"
 24 #include "include/cred.h"
 25 #include "include/policy_ns.h"
 26 #include "include/label.h"
 27 #include "include/policy.h"
 28 
 29 /* root profile namespace */
 30 struct aa_ns *root_ns;
 31 const char *aa_hidden_ns_name = "---";
 32 
 33 /**
 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
 38  *
 39  * Returns: true if @view is visible from @curr else false
 40  */
 41 bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns)
 42 {
 43         if (curr == view)
 44                 return true;
 45 
 46         if (!subns)
 47                 return false;
 48 
 49         for ( ; view; view = view->parent) {
 50                 if (view->parent == curr)
 51                         return true;
 52         }
 53 
 54         return false;
 55 }
 56 
 57 /**
 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
 62  *
 63  * Returns: name of @view visible from @curr
 64  */
 65 const char *aa_ns_name(struct aa_ns *curr, struct aa_ns *view, bool subns)
 66 {
 67         /* if view == curr then the namespace name isn't displayed */
 68         if (curr == view)
 69                 return "";
 70 
 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
 77                  */
 78                 return view->base.hname + strlen(curr->base.hname) + 2;
 79         }
 80 
 81         return aa_hidden_ns_name;
 82 }
 83 
 84 /**
 85  * alloc_ns - allocate, initialize and return a new namespace
 86  * @prefix: parent namespace name (MAYBE NULL)
 87  * @name: a preallocated name  (NOT NULL)
 88  *
 89  * Returns: refcounted namespace or NULL on failure.
 90  */
 91 static struct aa_ns *alloc_ns(const char *prefix, const char *name)
 92 {
 93         struct aa_ns *ns;
 94 
 95         ns = kzalloc(sizeof(*ns), GFP_KERNEL);
 96         AA_DEBUG("%s(%p)\n", __func__, ns);
 97         if (!ns)
 98                 return NULL;
 99         if (!aa_policy_init(&ns->base, prefix, name, GFP_KERNEL))
100                 goto fail_ns;
101 
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);
106 
107         /* released by aa_free_ns() */
108         ns->unconfined = aa_alloc_profile("unconfined", NULL, GFP_KERNEL);
109         if (!ns->unconfined)
110                 goto fail_unconfined;
111 
112         ns->unconfined->label.flags |= FLAG_IX_ON_NAME_ERROR |
113                 FLAG_IMMUTIBLE | FLAG_NS_COUNT | FLAG_UNCONFINED;
114         ns->unconfined->mode = APPARMOR_UNCONFINED;
115         ns->unconfined->file.dfa = aa_get_dfa(nulldfa);
116         ns->unconfined->policy.dfa = aa_get_dfa(nulldfa);
117 
118         /* ns and ns->unconfined share ns->unconfined refcount */
119         ns->unconfined->ns = ns;
120 
121         atomic_set(&ns->uniq_null, 0);
122 
123         aa_labelset_init(&ns->labels);
124 
125         return ns;
126 
127 fail_unconfined:
128         kzfree(ns->base.hname);
129 fail_ns:
130         kzfree(ns);
131         return NULL;
132 }
133 
134 /**
135  * aa_free_ns - free a profile namespace
136  * @ns: the namespace to free  (MAYBE NULL)
137  *
138  * Requires: All references to the namespace must have been put, if the
139  *           namespace was referenced by a profile confining a task,
140  */
141 void aa_free_ns(struct aa_ns *ns)
142 {
143         if (!ns)
144                 return;
145 
146         aa_policy_destroy(&ns->base);
147         aa_labelset_destroy(&ns->labels);
148         aa_put_ns(ns->parent);
149 
150         ns->unconfined->ns = NULL;
151         aa_free_profile(ns->unconfined);
152         kzfree(ns);
153 }
154 
155 /**
156  * aa_findn_ns  -  look up a profile namespace on the namespace list
157  * @root: namespace to search in  (NOT NULL)
158  * @name: name of namespace to find  (NOT NULL)
159  * @n: length of @name
160  *
161  * Returns: a refcounted namespace on the list, or NULL if no namespace
162  *          called @name exists.
163  *
164  * refcount released by caller
165  */
166 struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n)
167 {
168         struct aa_ns *ns = NULL;
169 
170         rcu_read_lock();
171         ns = aa_get_ns(__aa_findn_ns(&root->sub_ns, name, n));
172         rcu_read_unlock();
173 
174         return ns;
175 }
176 
177 /**
178  * aa_find_ns  -  look up a profile namespace on the namespace list
179  * @root: namespace to search in  (NOT NULL)
180  * @name: name of namespace to find  (NOT NULL)
181  *
182  * Returns: a refcounted namespace on the list, or NULL if no namespace
183  *          called @name exists.
184  *
185  * refcount released by caller
186  */
187 struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name)
188 {
189         return aa_findn_ns(root, name, strlen(name));
190 }
191 
192 /**
193  * __aa_lookupn_ns - lookup the namespace matching @hname
194  * @base: base list to start looking up profile name from  (NOT NULL)
195  * @hname: hierarchical ns name  (NOT NULL)
196  * @n: length of @hname
197  *
198  * Requires: rcu_read_lock be held
199  *
200  * Returns: unrefcounted ns pointer or NULL if not found
201  *
202  * Do a relative name lookup, recursing through profile tree.
203  */
204 struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n)
205 {
206         struct aa_ns *ns = view;
207         const char *split;
208 
209         for (split = strnstr(hname, "//", n); split;
210              split = strnstr(hname, "//", n)) {
211                 ns = __aa_findn_ns(&ns->sub_ns, hname, split - hname);
212                 if (!ns)
213                         return NULL;
214 
215                 n -= split + 2 - hname;
216                 hname = split + 2;
217         }
218 
219         if (n)
220                 return __aa_findn_ns(&ns->sub_ns, hname, n);
221         return NULL;
222 }
223 
224 /**
225  * aa_lookupn_ns  -  look up a policy namespace relative to @view
226  * @view: namespace to search in  (NOT NULL)
227  * @name: name of namespace to find  (NOT NULL)
228  * @n: length of @name
229  *
230  * Returns: a refcounted namespace on the list, or NULL if no namespace
231  *          called @name exists.
232  *
233  * refcount released by caller
234  */
235 struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n)
236 {
237         struct aa_ns *ns = NULL;
238 
239         rcu_read_lock();
240         ns = aa_get_ns(__aa_lookupn_ns(view, name, n));
241         rcu_read_unlock();
242 
243         return ns;
244 }
245 
246 static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name,
247                                     struct dentry *dir)
248 {
249         struct aa_ns *ns;
250         int error;
251 
252         AA_BUG(!parent);
253         AA_BUG(!name);
254         AA_BUG(!mutex_is_locked(&parent->lock));
255 
256         ns = alloc_ns(parent->base.hname, name);
257         if (!ns)
258                 return NULL;
259         ns->level = parent->level + 1;
260         mutex_lock_nested(&ns->lock, ns->level);
261         error = __aafs_ns_mkdir(ns, ns_subns_dir(parent), name, dir);
262         if (error) {
263                 AA_ERROR("Failed to create interface for ns %s\n",
264                          ns->base.name);
265                 mutex_unlock(&ns->lock);
266                 aa_free_ns(ns);
267                 return ERR_PTR(error);
268         }
269         ns->parent = aa_get_ns(parent);
270         list_add_rcu(&ns->base.list, &parent->sub_ns);
271         /* add list ref */
272         aa_get_ns(ns);
273         mutex_unlock(&ns->lock);
274 
275         return ns;
276 }
277 
278 /**
279  * aa_create_ns - create an ns, fail if it already exists
280  * @parent: the parent of the namespace being created
281  * @name: the name of the namespace
282  * @dir: if not null the dir to put the ns entries in
283  *
284  * Returns: the a refcounted ns that has been add or an ERR_PTR
285  */
286 struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name,
287                                      struct dentry *dir)
288 {
289         struct aa_ns *ns;
290 
291         AA_BUG(!mutex_is_locked(&parent->lock));
292 
293         /* try and find the specified ns */
294         /* released by caller */
295         ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
296         if (!ns)
297                 ns = __aa_create_ns(parent, name, dir);
298         else
299                 ns = ERR_PTR(-EEXIST);
300 
301         /* return ref */
302         return ns;
303 }
304 
305 /**
306  * aa_prepare_ns - find an existing or create a new namespace of @name
307  * @parent: ns to treat as parent
308  * @name: the namespace to find or add  (NOT NULL)
309  *
310  * Returns: refcounted namespace or PTR_ERR if failed to create one
311  */
312 struct aa_ns *aa_prepare_ns(struct aa_ns *parent, const char *name)
313 {
314         struct aa_ns *ns;
315 
316         mutex_lock_nested(&parent->lock, parent->level);
317         /* try and find the specified ns and if it doesn't exist create it */
318         /* released by caller */
319         ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
320         if (!ns)
321                 ns = __aa_create_ns(parent, name, NULL);
322         mutex_unlock(&parent->lock);
323 
324         /* return ref */
325         return ns;
326 }
327 
328 static void __ns_list_release(struct list_head *head);
329 
330 /**
331  * destroy_ns - remove everything contained by @ns
332  * @ns: namespace to have it contents removed  (NOT NULL)
333  */
334 static void destroy_ns(struct aa_ns *ns)
335 {
336         if (!ns)
337                 return;
338 
339         mutex_lock_nested(&ns->lock, ns->level);
340         /* release all profiles in this namespace */
341         __aa_profile_list_release(&ns->base.profiles);
342 
343         /* release all sub namespaces */
344         __ns_list_release(&ns->sub_ns);
345 
346         if (ns->parent) {
347                 unsigned long flags;
348 
349                 write_lock_irqsave(&ns->labels.lock, flags);
350                 __aa_proxy_redirect(ns_unconfined(ns),
351                                     ns_unconfined(ns->parent));
352                 write_unlock_irqrestore(&ns->labels.lock, flags);
353         }
354         __aafs_ns_rmdir(ns);
355         mutex_unlock(&ns->lock);
356 }
357 
358 /**
359  * __aa_remove_ns - remove a namespace and all its children
360  * @ns: namespace to be removed  (NOT NULL)
361  *
362  * Requires: ns->parent->lock be held and ns removed from parent.
363  */
364 void __aa_remove_ns(struct aa_ns *ns)
365 {
366         /* remove ns from namespace list */
367         list_del_rcu(&ns->base.list);
368         destroy_ns(ns);
369         aa_put_ns(ns);
370 }
371 
372 /**
373  * __ns_list_release - remove all profile namespaces on the list put refs
374  * @head: list of profile namespaces  (NOT NULL)
375  *
376  * Requires: namespace lock be held
377  */
378 static void __ns_list_release(struct list_head *head)
379 {
380         struct aa_ns *ns, *tmp;
381 
382         list_for_each_entry_safe(ns, tmp, head, base.list)
383                 __aa_remove_ns(ns);
384 
385 }
386 
387 /**
388  * aa_alloc_root_ns - allocate the root profile namespace
389  *
390  * Returns: %0 on success else error
391  *
392  */
393 int __init aa_alloc_root_ns(void)
394 {
395         /* released by aa_free_root_ns - used as list ref*/
396         root_ns = alloc_ns(NULL, "root");
397         if (!root_ns)
398                 return -ENOMEM;
399 
400         return 0;
401 }
402 
403  /**
404   * aa_free_root_ns - free the root profile namespace
405   */
406 void __init aa_free_root_ns(void)
407 {
408          struct aa_ns *ns = root_ns;
409 
410          root_ns = NULL;
411 
412          destroy_ns(ns);
413          aa_put_ns(ns);
414 }
415 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp