blob: 4ad54eea1ea45554d5d931497671fdb32a33660b [file] [log] [blame]
David Howells973c9f42011-01-20 16:38:33 +00001/* Manage a process's keyrings
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
David Howells69664cf2008-04-29 01:01:31 -07003 * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/keyctl.h>
16#include <linux/fs.h>
17#include <linux/err.h>
Ingo Molnarbb003072006-03-22 00:09:14 -080018#include <linux/mutex.h>
David Howellsee18d642009-09-02 09:14:21 +010019#include <linux/security.h>
Serge E. Hallyn1d1e9752009-02-26 18:27:38 -060020#include <linux/user_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <asm/uaccess.h>
22#include "internal.h"
23
David Howells973c9f42011-01-20 16:38:33 +000024/* Session keyring create vs join semaphore */
Ingo Molnarbb003072006-03-22 00:09:14 -080025static DEFINE_MUTEX(key_session_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
David Howells973c9f42011-01-20 16:38:33 +000027/* User keyring creation semaphore */
David Howells69664cf2008-04-29 01:01:31 -070028static DEFINE_MUTEX(key_user_keyring_mutex);
29
David Howells973c9f42011-01-20 16:38:33 +000030/* The root user's tracking struct */
Linus Torvalds1da177e2005-04-16 15:20:36 -070031struct key_user root_key_user = {
32 .usage = ATOMIC_INIT(3),
David Howells76181c12007-10-16 23:29:46 -070033 .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock),
Peter Zijlstra6cfd76a2006-12-06 20:37:22 -080034 .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock),
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 .nkeys = ATOMIC_INIT(2),
36 .nikeys = ATOMIC_INIT(2),
37 .uid = 0,
Serge E. Hallyn1d1e9752009-02-26 18:27:38 -060038 .user_ns = &init_user_ns,
Linus Torvalds1da177e2005-04-16 15:20:36 -070039};
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041/*
David Howells973c9f42011-01-20 16:38:33 +000042 * Install the user and user session keyrings for the current process's UID.
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 */
David Howells8bbf49762008-11-14 10:39:14 +110044int install_user_keyrings(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045{
David Howellsd84f4f92008-11-14 10:39:23 +110046 struct user_struct *user;
47 const struct cred *cred;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 struct key *uid_keyring, *session_keyring;
49 char buf[20];
50 int ret;
51
David Howellsd84f4f92008-11-14 10:39:23 +110052 cred = current_cred();
53 user = cred->user;
54
David Howells69664cf2008-04-29 01:01:31 -070055 kenter("%p{%u}", user, user->uid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
David Howells69664cf2008-04-29 01:01:31 -070057 if (user->uid_keyring) {
58 kleave(" = 0 [exist]");
59 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 }
61
David Howells69664cf2008-04-29 01:01:31 -070062 mutex_lock(&key_user_keyring_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 ret = 0;
64
David Howells69664cf2008-04-29 01:01:31 -070065 if (!user->uid_keyring) {
66 /* get the UID-specific keyring
67 * - there may be one in existence already as it may have been
68 * pinned by a session, but the user_struct pointing to it
69 * may have been destroyed by setuid */
70 sprintf(buf, "_uid.%u", user->uid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
David Howells69664cf2008-04-29 01:01:31 -070072 uid_keyring = find_keyring_by_name(buf, true);
73 if (IS_ERR(uid_keyring)) {
74 uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
David Howellsd84f4f92008-11-14 10:39:23 +110075 cred, KEY_ALLOC_IN_QUOTA,
David Howells69664cf2008-04-29 01:01:31 -070076 NULL);
77 if (IS_ERR(uid_keyring)) {
78 ret = PTR_ERR(uid_keyring);
79 goto error;
80 }
81 }
82
83 /* get a default session keyring (which might also exist
84 * already) */
85 sprintf(buf, "_uid_ses.%u", user->uid);
86
87 session_keyring = find_keyring_by_name(buf, true);
88 if (IS_ERR(session_keyring)) {
89 session_keyring =
90 keyring_alloc(buf, user->uid, (gid_t) -1,
David Howellsd84f4f92008-11-14 10:39:23 +110091 cred, KEY_ALLOC_IN_QUOTA, NULL);
David Howells69664cf2008-04-29 01:01:31 -070092 if (IS_ERR(session_keyring)) {
93 ret = PTR_ERR(session_keyring);
94 goto error_release;
95 }
96
97 /* we install a link from the user session keyring to
98 * the user keyring */
99 ret = key_link(session_keyring, uid_keyring);
100 if (ret < 0)
101 goto error_release_both;
102 }
103
104 /* install the keyrings */
105 user->uid_keyring = uid_keyring;
106 user->session_keyring = session_keyring;
107 }
108
109 mutex_unlock(&key_user_keyring_mutex);
110 kleave(" = 0");
111 return 0;
112
113error_release_both:
114 key_put(session_keyring);
115error_release:
116 key_put(uid_keyring);
117error:
118 mutex_unlock(&key_user_keyring_mutex);
119 kleave(" = %d", ret);
120 return ret;
121}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123/*
David Howells973c9f42011-01-20 16:38:33 +0000124 * Install a fresh thread keyring directly to new credentials. This keyring is
125 * allowed to overrun the quota.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 */
David Howellsd84f4f92008-11-14 10:39:23 +1100127int install_thread_keyring_to_cred(struct cred *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
David Howellsd84f4f92008-11-14 10:39:23 +1100129 struct key *keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
David Howellsd84f4f92008-11-14 10:39:23 +1100131 keyring = keyring_alloc("_tid", new->uid, new->gid, new,
132 KEY_ALLOC_QUOTA_OVERRUN, NULL);
133 if (IS_ERR(keyring))
134 return PTR_ERR(keyring);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
David Howellsd84f4f92008-11-14 10:39:23 +1100136 new->thread_keyring = keyring;
137 return 0;
138}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140/*
David Howells973c9f42011-01-20 16:38:33 +0000141 * Install a fresh thread keyring, discarding the old one.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 */
David Howellsd84f4f92008-11-14 10:39:23 +1100143static int install_thread_keyring(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
David Howellsd84f4f92008-11-14 10:39:23 +1100145 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 int ret;
147
David Howellsd84f4f92008-11-14 10:39:23 +1100148 new = prepare_creds();
149 if (!new)
150 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
David Howellsd84f4f92008-11-14 10:39:23 +1100152 BUG_ON(new->thread_keyring);
153
154 ret = install_thread_keyring_to_cred(new);
155 if (ret < 0) {
156 abort_creds(new);
157 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 }
159
David Howellsd84f4f92008-11-14 10:39:23 +1100160 return commit_creds(new);
161}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
David Howellsd84f4f92008-11-14 10:39:23 +1100163/*
David Howells973c9f42011-01-20 16:38:33 +0000164 * Install a process keyring directly to a credentials struct.
165 *
166 * Returns -EEXIST if there was already a process keyring, 0 if one installed,
167 * and other value on any other error
David Howellsd84f4f92008-11-14 10:39:23 +1100168 */
169int install_process_keyring_to_cred(struct cred *new)
170{
171 struct key *keyring;
172 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
David Howellsd84f4f92008-11-14 10:39:23 +1100174 if (new->tgcred->process_keyring)
175 return -EEXIST;
176
177 keyring = keyring_alloc("_pid", new->uid, new->gid,
178 new, KEY_ALLOC_QUOTA_OVERRUN, NULL);
179 if (IS_ERR(keyring))
180 return PTR_ERR(keyring);
181
182 spin_lock_irq(&new->tgcred->lock);
183 if (!new->tgcred->process_keyring) {
184 new->tgcred->process_keyring = keyring;
185 keyring = NULL;
186 ret = 0;
187 } else {
188 ret = -EEXIST;
189 }
190 spin_unlock_irq(&new->tgcred->lock);
191 key_put(keyring);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 return ret;
David Howellsd84f4f92008-11-14 10:39:23 +1100193}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195/*
David Howells973c9f42011-01-20 16:38:33 +0000196 * Make sure a process keyring is installed for the current process. The
197 * existing process keyring is not replaced.
198 *
199 * Returns 0 if there is a process keyring by the end of this function, some
200 * error otherwise.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 */
David Howellsd84f4f92008-11-14 10:39:23 +1100202static int install_process_keyring(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203{
David Howellsd84f4f92008-11-14 10:39:23 +1100204 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 int ret;
206
David Howellsd84f4f92008-11-14 10:39:23 +1100207 new = prepare_creds();
208 if (!new)
209 return -ENOMEM;
David Howells1a26feb2006-04-10 22:54:26 -0700210
David Howellsd84f4f92008-11-14 10:39:23 +1100211 ret = install_process_keyring_to_cred(new);
212 if (ret < 0) {
213 abort_creds(new);
Andi Kleen27d63792010-10-28 13:16:13 +0100214 return ret != -EEXIST ? ret : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 }
216
David Howellsd84f4f92008-11-14 10:39:23 +1100217 return commit_creds(new);
218}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220/*
David Howells973c9f42011-01-20 16:38:33 +0000221 * Install a session keyring directly to a credentials struct.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 */
Oleg Nesterov685bfd22010-05-26 14:43:00 -0700223int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
David Howells7e047ef2006-06-26 00:24:50 -0700225 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 struct key *old;
David Howells1a26feb2006-04-10 22:54:26 -0700227
228 might_sleep();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 /* create an empty session keyring */
231 if (!keyring) {
David Howells7e047ef2006-06-26 00:24:50 -0700232 flags = KEY_ALLOC_QUOTA_OVERRUN;
David Howellsd84f4f92008-11-14 10:39:23 +1100233 if (cred->tgcred->session_keyring)
David Howells7e047ef2006-06-26 00:24:50 -0700234 flags = KEY_ALLOC_IN_QUOTA;
235
David Howellsd84f4f92008-11-14 10:39:23 +1100236 keyring = keyring_alloc("_ses", cred->uid, cred->gid,
237 cred, flags, NULL);
David Howells1a26feb2006-04-10 22:54:26 -0700238 if (IS_ERR(keyring))
239 return PTR_ERR(keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100240 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 atomic_inc(&keyring->usage);
242 }
243
244 /* install the keyring */
David Howellsd84f4f92008-11-14 10:39:23 +1100245 spin_lock_irq(&cred->tgcred->lock);
246 old = cred->tgcred->session_keyring;
247 rcu_assign_pointer(cred->tgcred->session_keyring, keyring);
248 spin_unlock_irq(&cred->tgcred->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
David Howells1a26feb2006-04-10 22:54:26 -0700250 /* we're using RCU on the pointer, but there's no point synchronising
251 * on it if it didn't previously point to anything */
252 if (old) {
253 synchronize_rcu();
254 key_put(old);
255 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
David Howells1a26feb2006-04-10 22:54:26 -0700257 return 0;
David Howellsd84f4f92008-11-14 10:39:23 +1100258}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260/*
David Howells973c9f42011-01-20 16:38:33 +0000261 * Install a session keyring, discarding the old one. If a keyring is not
262 * supplied, an empty one is invented.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 */
David Howellsd84f4f92008-11-14 10:39:23 +1100264static int install_session_keyring(struct key *keyring)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265{
David Howellsd84f4f92008-11-14 10:39:23 +1100266 struct cred *new;
267 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
David Howellsd84f4f92008-11-14 10:39:23 +1100269 new = prepare_creds();
270 if (!new)
271 return -ENOMEM;
David Howellsb5f545c2006-01-08 01:02:47 -0800272
David Howells995995372011-08-22 14:08:33 +0100273 ret = install_session_keyring_to_cred(new, keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100274 if (ret < 0) {
275 abort_creds(new);
276 return ret;
277 }
David Howellsb5f545c2006-01-08 01:02:47 -0800278
David Howellsd84f4f92008-11-14 10:39:23 +1100279 return commit_creds(new);
280}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282/*
David Howells973c9f42011-01-20 16:38:33 +0000283 * Handle the fsuid changing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 */
285void key_fsuid_changed(struct task_struct *tsk)
286{
287 /* update the ownership of the thread keyring */
David Howellsb6dff3e2008-11-14 10:39:16 +1100288 BUG_ON(!tsk->cred);
289 if (tsk->cred->thread_keyring) {
290 down_write(&tsk->cred->thread_keyring->sem);
291 tsk->cred->thread_keyring->uid = tsk->cred->fsuid;
292 up_write(&tsk->cred->thread_keyring->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 }
David Howellsa8b17ed2011-01-20 16:38:27 +0000294}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296/*
David Howells973c9f42011-01-20 16:38:33 +0000297 * Handle the fsgid changing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 */
299void key_fsgid_changed(struct task_struct *tsk)
300{
301 /* update the ownership of the thread keyring */
David Howellsb6dff3e2008-11-14 10:39:16 +1100302 BUG_ON(!tsk->cred);
303 if (tsk->cred->thread_keyring) {
304 down_write(&tsk->cred->thread_keyring->sem);
305 tsk->cred->thread_keyring->gid = tsk->cred->fsgid;
306 up_write(&tsk->cred->thread_keyring->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 }
David Howellsa8b17ed2011-01-20 16:38:27 +0000308}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310/*
David Howells973c9f42011-01-20 16:38:33 +0000311 * Search the process keyrings attached to the supplied cred for the first
312 * matching key.
313 *
314 * The search criteria are the type and the match function. The description is
315 * given to the match function as a parameter, but doesn't otherwise influence
316 * the search. Typically the match function will compare the description
317 * parameter to the key's description.
318 *
319 * This can only search keyrings that grant Search permission to the supplied
320 * credentials. Keyrings linked to searched keyrings will also be searched if
321 * they grant Search permission too. Keys can only be found if they grant
322 * Search permission to the credentials.
323 *
324 * Returns a pointer to the key with the key usage count incremented if
325 * successful, -EAGAIN if we didn't find any matching key or -ENOKEY if we only
326 * matched negative keys.
327 *
328 * In the case of a successful return, the possession attribute is set on the
329 * returned key reference.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 */
David Howells927942a2010-06-11 17:31:10 +0100331key_ref_t search_my_process_keyrings(struct key_type *type,
332 const void *description,
333 key_match_func_t match,
David Howells78b72802011-03-11 17:57:23 +0000334 bool no_state_check,
David Howells927942a2010-06-11 17:31:10 +0100335 const struct cred *cred)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336{
David Howellsb5f545c2006-01-08 01:02:47 -0800337 key_ref_t key_ref, ret, err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
339 /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
340 * searchable, but we failed to find a key or we found a negative key;
341 * otherwise we want to return a sample error (probably -EACCES) if
342 * none of the keyrings were searchable
343 *
344 * in terms of priority: success > -ENOKEY > -EAGAIN > other error
345 */
David Howells664cceb2005-09-28 17:03:15 +0100346 key_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 ret = NULL;
348 err = ERR_PTR(-EAGAIN);
349
350 /* search the thread keyring first */
David Howellsc69e8d92008-11-14 10:39:19 +1100351 if (cred->thread_keyring) {
David Howells664cceb2005-09-28 17:03:15 +0100352 key_ref = keyring_search_aux(
David Howellsc69e8d92008-11-14 10:39:19 +1100353 make_key_ref(cred->thread_keyring, 1),
David Howells78b72802011-03-11 17:57:23 +0000354 cred, type, description, match, no_state_check);
David Howells664cceb2005-09-28 17:03:15 +0100355 if (!IS_ERR(key_ref))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 goto found;
357
David Howells664cceb2005-09-28 17:03:15 +0100358 switch (PTR_ERR(key_ref)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 case -EAGAIN: /* no key */
360 if (ret)
361 break;
362 case -ENOKEY: /* negative key */
David Howells664cceb2005-09-28 17:03:15 +0100363 ret = key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 break;
365 default:
David Howells664cceb2005-09-28 17:03:15 +0100366 err = key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 break;
368 }
369 }
370
371 /* search the process keyring second */
David Howellsbb952bb2008-11-14 10:39:20 +1100372 if (cred->tgcred->process_keyring) {
David Howells664cceb2005-09-28 17:03:15 +0100373 key_ref = keyring_search_aux(
David Howellsbb952bb2008-11-14 10:39:20 +1100374 make_key_ref(cred->tgcred->process_keyring, 1),
David Howells78b72802011-03-11 17:57:23 +0000375 cred, type, description, match, no_state_check);
David Howells664cceb2005-09-28 17:03:15 +0100376 if (!IS_ERR(key_ref))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 goto found;
378
David Howells664cceb2005-09-28 17:03:15 +0100379 switch (PTR_ERR(key_ref)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 case -EAGAIN: /* no key */
381 if (ret)
382 break;
383 case -ENOKEY: /* negative key */
David Howells664cceb2005-09-28 17:03:15 +0100384 ret = key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 break;
386 default:
David Howells664cceb2005-09-28 17:03:15 +0100387 err = key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 break;
389 }
390 }
391
David Howells3e301482005-06-23 22:00:56 -0700392 /* search the session keyring */
David Howellsbb952bb2008-11-14 10:39:20 +1100393 if (cred->tgcred->session_keyring) {
David Howells8589b4e2005-06-23 22:00:53 -0700394 rcu_read_lock();
David Howells664cceb2005-09-28 17:03:15 +0100395 key_ref = keyring_search_aux(
396 make_key_ref(rcu_dereference(
David Howellsbb952bb2008-11-14 10:39:20 +1100397 cred->tgcred->session_keyring),
David Howells664cceb2005-09-28 17:03:15 +0100398 1),
David Howells78b72802011-03-11 17:57:23 +0000399 cred, type, description, match, no_state_check);
David Howells8589b4e2005-06-23 22:00:53 -0700400 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
David Howells664cceb2005-09-28 17:03:15 +0100402 if (!IS_ERR(key_ref))
David Howells3e301482005-06-23 22:00:56 -0700403 goto found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
David Howells664cceb2005-09-28 17:03:15 +0100405 switch (PTR_ERR(key_ref)) {
David Howells3e301482005-06-23 22:00:56 -0700406 case -EAGAIN: /* no key */
407 if (ret)
408 break;
409 case -ENOKEY: /* negative key */
David Howells664cceb2005-09-28 17:03:15 +0100410 ret = key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 break;
David Howells3e301482005-06-23 22:00:56 -0700412 default:
David Howells664cceb2005-09-28 17:03:15 +0100413 err = key_ref;
David Howells3e301482005-06-23 22:00:56 -0700414 break;
415 }
David Howells3e301482005-06-23 22:00:56 -0700416 }
417 /* or search the user-session keyring */
David Howellsc69e8d92008-11-14 10:39:19 +1100418 else if (cred->user->session_keyring) {
David Howells664cceb2005-09-28 17:03:15 +0100419 key_ref = keyring_search_aux(
David Howellsc69e8d92008-11-14 10:39:19 +1100420 make_key_ref(cred->user->session_keyring, 1),
David Howells78b72802011-03-11 17:57:23 +0000421 cred, type, description, match, no_state_check);
David Howells664cceb2005-09-28 17:03:15 +0100422 if (!IS_ERR(key_ref))
David Howells3e301482005-06-23 22:00:56 -0700423 goto found;
424
David Howells664cceb2005-09-28 17:03:15 +0100425 switch (PTR_ERR(key_ref)) {
David Howells3e301482005-06-23 22:00:56 -0700426 case -EAGAIN: /* no key */
427 if (ret)
428 break;
429 case -ENOKEY: /* negative key */
David Howells664cceb2005-09-28 17:03:15 +0100430 ret = key_ref;
David Howells3e301482005-06-23 22:00:56 -0700431 break;
432 default:
David Howells664cceb2005-09-28 17:03:15 +0100433 err = key_ref;
David Howells3e301482005-06-23 22:00:56 -0700434 break;
435 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 }
437
David Howells927942a2010-06-11 17:31:10 +0100438 /* no key - decide on the error we're going to go for */
439 key_ref = ret ? ret : err;
440
441found:
442 return key_ref;
443}
444
David Howells927942a2010-06-11 17:31:10 +0100445/*
David Howells973c9f42011-01-20 16:38:33 +0000446 * Search the process keyrings attached to the supplied cred for the first
447 * matching key in the manner of search_my_process_keyrings(), but also search
448 * the keys attached to the assumed authorisation key using its credentials if
449 * one is available.
450 *
451 * Return same as search_my_process_keyrings().
David Howells927942a2010-06-11 17:31:10 +0100452 */
453key_ref_t search_process_keyrings(struct key_type *type,
454 const void *description,
455 key_match_func_t match,
456 const struct cred *cred)
457{
458 struct request_key_auth *rka;
459 key_ref_t key_ref, ret = ERR_PTR(-EACCES), err;
460
461 might_sleep();
462
David Howells78b72802011-03-11 17:57:23 +0000463 key_ref = search_my_process_keyrings(type, description, match,
464 false, cred);
David Howells927942a2010-06-11 17:31:10 +0100465 if (!IS_ERR(key_ref))
466 goto found;
467 err = key_ref;
468
David Howellsb5f545c2006-01-08 01:02:47 -0800469 /* if this process has an instantiation authorisation key, then we also
470 * search the keyrings of the process mentioned there
471 * - we don't permit access to request_key auth keys via this method
472 */
David Howellsc69e8d92008-11-14 10:39:19 +1100473 if (cred->request_key_auth &&
David Howellsd84f4f92008-11-14 10:39:23 +1100474 cred == current_cred() &&
David Howells04c567d2006-06-22 14:47:18 -0700475 type != &key_type_request_key_auth
David Howellsb5f545c2006-01-08 01:02:47 -0800476 ) {
David Howells04c567d2006-06-22 14:47:18 -0700477 /* defend against the auth key being revoked */
David Howellsc69e8d92008-11-14 10:39:19 +1100478 down_read(&cred->request_key_auth->sem);
David Howells3e301482005-06-23 22:00:56 -0700479
David Howellsc69e8d92008-11-14 10:39:19 +1100480 if (key_validate(cred->request_key_auth) == 0) {
481 rka = cred->request_key_auth->payload.data;
David Howellsb5f545c2006-01-08 01:02:47 -0800482
David Howells04c567d2006-06-22 14:47:18 -0700483 key_ref = search_process_keyrings(type, description,
David Howellsd84f4f92008-11-14 10:39:23 +1100484 match, rka->cred);
David Howellsb5f545c2006-01-08 01:02:47 -0800485
David Howellsc69e8d92008-11-14 10:39:19 +1100486 up_read(&cred->request_key_auth->sem);
David Howells04c567d2006-06-22 14:47:18 -0700487
488 if (!IS_ERR(key_ref))
489 goto found;
490
David Howells927942a2010-06-11 17:31:10 +0100491 ret = key_ref;
David Howells04c567d2006-06-22 14:47:18 -0700492 } else {
David Howellsc69e8d92008-11-14 10:39:19 +1100493 up_read(&cred->request_key_auth->sem);
David Howellsb5f545c2006-01-08 01:02:47 -0800494 }
495 }
496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 /* no key - decide on the error we're going to go for */
David Howells927942a2010-06-11 17:31:10 +0100498 if (err == ERR_PTR(-ENOKEY) || ret == ERR_PTR(-ENOKEY))
499 key_ref = ERR_PTR(-ENOKEY);
500 else if (err == ERR_PTR(-EACCES))
501 key_ref = ret;
502 else
503 key_ref = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
David Howells3e301482005-06-23 22:00:56 -0700505found:
David Howells664cceb2005-09-28 17:03:15 +0100506 return key_ref;
David Howellsa8b17ed2011-01-20 16:38:27 +0000507}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509/*
David Howells973c9f42011-01-20 16:38:33 +0000510 * See if the key we're looking at is the target key.
David Howells664cceb2005-09-28 17:03:15 +0100511 */
David Howells927942a2010-06-11 17:31:10 +0100512int lookup_user_key_possessed(const struct key *key, const void *target)
David Howells664cceb2005-09-28 17:03:15 +0100513{
514 return key == target;
David Howellsa8b17ed2011-01-20 16:38:27 +0000515}
David Howells664cceb2005-09-28 17:03:15 +0100516
David Howells664cceb2005-09-28 17:03:15 +0100517/*
David Howells973c9f42011-01-20 16:38:33 +0000518 * Look up a key ID given us by userspace with a given permissions mask to get
519 * the key it refers to.
520 *
521 * Flags can be passed to request that special keyrings be created if referred
522 * to directly, to permit partially constructed keys to be found and to skip
523 * validity and permission checks on the found key.
524 *
525 * Returns a pointer to the key with an incremented usage count if successful;
526 * -EINVAL if the key ID is invalid; -ENOKEY if the key ID does not correspond
527 * to a key or the best found key was a negative key; -EKEYREVOKED or
528 * -EKEYEXPIRED if the best found key was revoked or expired; -EACCES if the
529 * found key doesn't grant the requested permit or the LSM denied access to it;
530 * or -ENOMEM if a special keyring couldn't be created.
531 *
532 * In the case of a successful return, the possession attribute is set on the
533 * returned key reference.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 */
David Howells55931222009-09-02 09:13:45 +0100535key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
David Howells8bbf49762008-11-14 10:39:14 +1100536 key_perm_t perm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537{
David Howells8bbf49762008-11-14 10:39:14 +1100538 struct request_key_auth *rka;
David Howellsd84f4f92008-11-14 10:39:23 +1100539 const struct cred *cred;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 struct key *key;
David Howellsb6dff3e2008-11-14 10:39:16 +1100541 key_ref_t key_ref, skey_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 int ret;
543
David Howellsbb952bb2008-11-14 10:39:20 +1100544try_again:
545 cred = get_current_cred();
David Howells664cceb2005-09-28 17:03:15 +0100546 key_ref = ERR_PTR(-ENOKEY);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547
548 switch (id) {
549 case KEY_SPEC_THREAD_KEYRING:
David Howellsb6dff3e2008-11-14 10:39:16 +1100550 if (!cred->thread_keyring) {
David Howells55931222009-09-02 09:13:45 +0100551 if (!(lflags & KEY_LOOKUP_CREATE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 goto error;
553
David Howells8bbf49762008-11-14 10:39:14 +1100554 ret = install_thread_keyring();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 if (ret < 0) {
Dan Carpenter4d09ec02010-05-17 14:42:35 +0100556 key_ref = ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 goto error;
558 }
David Howellsbb952bb2008-11-14 10:39:20 +1100559 goto reget_creds;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 }
561
David Howellsb6dff3e2008-11-14 10:39:16 +1100562 key = cred->thread_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 atomic_inc(&key->usage);
David Howells664cceb2005-09-28 17:03:15 +0100564 key_ref = make_key_ref(key, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 break;
566
567 case KEY_SPEC_PROCESS_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100568 if (!cred->tgcred->process_keyring) {
David Howells55931222009-09-02 09:13:45 +0100569 if (!(lflags & KEY_LOOKUP_CREATE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 goto error;
571
David Howells8bbf49762008-11-14 10:39:14 +1100572 ret = install_process_keyring();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 if (ret < 0) {
Dan Carpenter4d09ec02010-05-17 14:42:35 +0100574 key_ref = ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 goto error;
576 }
David Howellsbb952bb2008-11-14 10:39:20 +1100577 goto reget_creds;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 }
579
David Howellsbb952bb2008-11-14 10:39:20 +1100580 key = cred->tgcred->process_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 atomic_inc(&key->usage);
David Howells664cceb2005-09-28 17:03:15 +0100582 key_ref = make_key_ref(key, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 break;
584
585 case KEY_SPEC_SESSION_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100586 if (!cred->tgcred->session_keyring) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 /* always install a session keyring upon access if one
588 * doesn't exist yet */
David Howells8bbf49762008-11-14 10:39:14 +1100589 ret = install_user_keyrings();
David Howells69664cf2008-04-29 01:01:31 -0700590 if (ret < 0)
591 goto error;
David Howells3ecf1b42011-08-22 14:08:43 +0100592 if (lflags & KEY_LOOKUP_CREATE)
593 ret = join_session_keyring(NULL);
594 else
595 ret = install_session_keyring(
596 cred->user->session_keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100597
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 if (ret < 0)
599 goto error;
David Howellsbb952bb2008-11-14 10:39:20 +1100600 goto reget_creds;
David Howells3ecf1b42011-08-22 14:08:43 +0100601 } else if (cred->tgcred->session_keyring ==
602 cred->user->session_keyring &&
603 lflags & KEY_LOOKUP_CREATE) {
604 ret = join_session_keyring(NULL);
605 if (ret < 0)
606 goto error;
607 goto reget_creds;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 }
609
David Howells3e301482005-06-23 22:00:56 -0700610 rcu_read_lock();
David Howellsbb952bb2008-11-14 10:39:20 +1100611 key = rcu_dereference(cred->tgcred->session_keyring);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 atomic_inc(&key->usage);
David Howells3e301482005-06-23 22:00:56 -0700613 rcu_read_unlock();
David Howells664cceb2005-09-28 17:03:15 +0100614 key_ref = make_key_ref(key, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 break;
616
617 case KEY_SPEC_USER_KEYRING:
David Howellsb6dff3e2008-11-14 10:39:16 +1100618 if (!cred->user->uid_keyring) {
David Howells8bbf49762008-11-14 10:39:14 +1100619 ret = install_user_keyrings();
David Howells69664cf2008-04-29 01:01:31 -0700620 if (ret < 0)
621 goto error;
622 }
623
David Howellsb6dff3e2008-11-14 10:39:16 +1100624 key = cred->user->uid_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 atomic_inc(&key->usage);
David Howells664cceb2005-09-28 17:03:15 +0100626 key_ref = make_key_ref(key, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 break;
628
629 case KEY_SPEC_USER_SESSION_KEYRING:
David Howellsb6dff3e2008-11-14 10:39:16 +1100630 if (!cred->user->session_keyring) {
David Howells8bbf49762008-11-14 10:39:14 +1100631 ret = install_user_keyrings();
David Howells69664cf2008-04-29 01:01:31 -0700632 if (ret < 0)
633 goto error;
634 }
635
David Howellsb6dff3e2008-11-14 10:39:16 +1100636 key = cred->user->session_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 atomic_inc(&key->usage);
David Howells664cceb2005-09-28 17:03:15 +0100638 key_ref = make_key_ref(key, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 break;
640
641 case KEY_SPEC_GROUP_KEYRING:
642 /* group keyrings are not yet supported */
Dan Carpenter4d09ec02010-05-17 14:42:35 +0100643 key_ref = ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 goto error;
645
David Howellsb5f545c2006-01-08 01:02:47 -0800646 case KEY_SPEC_REQKEY_AUTH_KEY:
David Howellsb6dff3e2008-11-14 10:39:16 +1100647 key = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -0800648 if (!key)
649 goto error;
650
651 atomic_inc(&key->usage);
652 key_ref = make_key_ref(key, 1);
653 break;
654
David Howells8bbf49762008-11-14 10:39:14 +1100655 case KEY_SPEC_REQUESTOR_KEYRING:
David Howellsb6dff3e2008-11-14 10:39:16 +1100656 if (!cred->request_key_auth)
David Howells8bbf49762008-11-14 10:39:14 +1100657 goto error;
658
David Howellsb6dff3e2008-11-14 10:39:16 +1100659 down_read(&cred->request_key_auth->sem);
Dan Carpenterf67dabb2012-03-06 13:32:16 +0000660 if (test_bit(KEY_FLAG_REVOKED,
661 &cred->request_key_auth->flags)) {
David Howells8bbf49762008-11-14 10:39:14 +1100662 key_ref = ERR_PTR(-EKEYREVOKED);
663 key = NULL;
664 } else {
David Howellsb6dff3e2008-11-14 10:39:16 +1100665 rka = cred->request_key_auth->payload.data;
David Howells8bbf49762008-11-14 10:39:14 +1100666 key = rka->dest_keyring;
667 atomic_inc(&key->usage);
668 }
David Howellsb6dff3e2008-11-14 10:39:16 +1100669 up_read(&cred->request_key_auth->sem);
David Howells8bbf49762008-11-14 10:39:14 +1100670 if (!key)
671 goto error;
672 key_ref = make_key_ref(key, 1);
673 break;
674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 default:
David Howells664cceb2005-09-28 17:03:15 +0100676 key_ref = ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 if (id < 1)
678 goto error;
679
680 key = key_lookup(id);
David Howells664cceb2005-09-28 17:03:15 +0100681 if (IS_ERR(key)) {
David Howellse231c2e2008-02-07 00:15:26 -0800682 key_ref = ERR_CAST(key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100684 }
685
686 key_ref = make_key_ref(key, 0);
687
688 /* check to see if we possess the key */
689 skey_ref = search_process_keyrings(key->type, key,
690 lookup_user_key_possessed,
David Howellsd84f4f92008-11-14 10:39:23 +1100691 cred);
David Howells664cceb2005-09-28 17:03:15 +0100692
693 if (!IS_ERR(skey_ref)) {
694 key_put(key);
695 key_ref = skey_ref;
696 }
697
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 break;
699 }
700
David Howells55931222009-09-02 09:13:45 +0100701 /* unlink does not use the nominated key in any way, so can skip all
702 * the permission checks as it is only concerned with the keyring */
703 if (lflags & KEY_LOOKUP_FOR_UNLINK) {
704 ret = 0;
705 goto error;
706 }
707
708 if (!(lflags & KEY_LOOKUP_PARTIAL)) {
David Howells76181c12007-10-16 23:29:46 -0700709 ret = wait_for_key_construction(key, true);
710 switch (ret) {
711 case -ERESTARTSYS:
712 goto invalid_key;
713 default:
714 if (perm)
715 goto invalid_key;
716 case 0:
717 break;
718 }
719 } else if (perm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 ret = key_validate(key);
721 if (ret < 0)
722 goto invalid_key;
723 }
724
725 ret = -EIO;
David Howells55931222009-09-02 09:13:45 +0100726 if (!(lflags & KEY_LOOKUP_PARTIAL) &&
727 !test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 goto invalid_key;
729
David Howells3e301482005-06-23 22:00:56 -0700730 /* check the permissions */
David Howellsd84f4f92008-11-14 10:39:23 +1100731 ret = key_task_permission(key_ref, cred, perm);
David Howells29db9192005-10-30 15:02:44 -0800732 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 goto invalid_key;
734
David Howells31d5a792012-05-11 10:56:56 +0100735 key->last_used_at = current_kernel_time().tv_sec;
736
David Howells664cceb2005-09-28 17:03:15 +0100737error:
David Howellsbb952bb2008-11-14 10:39:20 +1100738 put_cred(cred);
David Howells664cceb2005-09-28 17:03:15 +0100739 return key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740
David Howells664cceb2005-09-28 17:03:15 +0100741invalid_key:
742 key_ref_put(key_ref);
743 key_ref = ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 goto error;
745
David Howellsbb952bb2008-11-14 10:39:20 +1100746 /* if we attempted to install a keyring, then it may have caused new
747 * creds to be installed */
748reget_creds:
749 put_cred(cred);
750 goto try_again;
David Howellsa8b17ed2011-01-20 16:38:27 +0000751}
David Howellsbb952bb2008-11-14 10:39:20 +1100752
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753/*
David Howells973c9f42011-01-20 16:38:33 +0000754 * Join the named keyring as the session keyring if possible else attempt to
755 * create a new one of that name and join that.
756 *
757 * If the name is NULL, an empty anonymous keyring will be installed as the
758 * session keyring.
759 *
760 * Named session keyrings are joined with a semaphore held to prevent the
761 * keyrings from going away whilst the attempt is made to going them and also
762 * to prevent a race in creating compatible session keyrings.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 */
764long join_session_keyring(const char *name)
765{
David Howellsd84f4f92008-11-14 10:39:23 +1100766 const struct cred *old;
767 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 struct key *keyring;
David Howellsd84f4f92008-11-14 10:39:23 +1100769 long ret, serial;
770
771 /* only permit this if there's a single thread in the thread group -
772 * this avoids us having to adjust the creds on all threads and risking
773 * ENOMEM */
Oleg Nesterov5bb459b2009-07-10 03:48:23 +0200774 if (!current_is_single_threaded())
David Howellsd84f4f92008-11-14 10:39:23 +1100775 return -EMLINK;
776
777 new = prepare_creds();
778 if (!new)
779 return -ENOMEM;
780 old = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781
782 /* if no name is provided, install an anonymous keyring */
783 if (!name) {
David Howellsd84f4f92008-11-14 10:39:23 +1100784 ret = install_session_keyring_to_cred(new, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 if (ret < 0)
786 goto error;
787
David Howellsd84f4f92008-11-14 10:39:23 +1100788 serial = new->tgcred->session_keyring->serial;
789 ret = commit_creds(new);
790 if (ret == 0)
791 ret = serial;
792 goto okay;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 }
794
795 /* allow the user to join or create a named keyring */
Ingo Molnarbb003072006-03-22 00:09:14 -0800796 mutex_lock(&key_session_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
798 /* look for an existing keyring of this name */
David Howells69664cf2008-04-29 01:01:31 -0700799 keyring = find_keyring_by_name(name, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 if (PTR_ERR(keyring) == -ENOKEY) {
801 /* not found - try and create a new one */
David Howellsd84f4f92008-11-14 10:39:23 +1100802 keyring = keyring_alloc(name, old->uid, old->gid, old,
David Howells7e047ef2006-06-26 00:24:50 -0700803 KEY_ALLOC_IN_QUOTA, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 if (IS_ERR(keyring)) {
805 ret = PTR_ERR(keyring);
David Howellsbcf945d2005-08-04 13:07:06 -0700806 goto error2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 }
David Howellsd84f4f92008-11-14 10:39:23 +1100808 } else if (IS_ERR(keyring)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 ret = PTR_ERR(keyring);
810 goto error2;
811 }
812
813 /* we've got a keyring - now to install it */
David Howellsd84f4f92008-11-14 10:39:23 +1100814 ret = install_session_keyring_to_cred(new, keyring);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 if (ret < 0)
816 goto error2;
817
David Howellsd84f4f92008-11-14 10:39:23 +1100818 commit_creds(new);
819 mutex_unlock(&key_session_mutex);
820
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821 ret = keyring->serial;
822 key_put(keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100823okay:
824 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825
David Howells664cceb2005-09-28 17:03:15 +0100826error2:
Ingo Molnarbb003072006-03-22 00:09:14 -0800827 mutex_unlock(&key_session_mutex);
David Howells664cceb2005-09-28 17:03:15 +0100828error:
David Howellsd84f4f92008-11-14 10:39:23 +1100829 abort_creds(new);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 return ret;
David Howellsd84f4f92008-11-14 10:39:23 +1100831}
David Howellsee18d642009-09-02 09:14:21 +0100832
833/*
David Howells973c9f42011-01-20 16:38:33 +0000834 * Replace a process's session keyring on behalf of one of its children when
835 * the target process is about to resume userspace execution.
David Howellsee18d642009-09-02 09:14:21 +0100836 */
Oleg Nesterov413cd3d2012-05-11 10:59:08 +1000837void key_change_session_keyring(struct task_work *twork)
David Howellsee18d642009-09-02 09:14:21 +0100838{
Oleg Nesterov413cd3d2012-05-11 10:59:08 +1000839 const struct cred *old = current_cred();
840 struct cred *new = twork->data;
David Howellsee18d642009-09-02 09:14:21 +0100841
Oleg Nesterov413cd3d2012-05-11 10:59:08 +1000842 kfree(twork);
843 if (unlikely(current->flags & PF_EXITING)) {
844 put_cred(new);
David Howellsee18d642009-09-02 09:14:21 +0100845 return;
Oleg Nesterov413cd3d2012-05-11 10:59:08 +1000846 }
David Howellsee18d642009-09-02 09:14:21 +0100847
David Howellsee18d642009-09-02 09:14:21 +0100848 new-> uid = old-> uid;
849 new-> euid = old-> euid;
850 new-> suid = old-> suid;
851 new->fsuid = old->fsuid;
852 new-> gid = old-> gid;
853 new-> egid = old-> egid;
854 new-> sgid = old-> sgid;
855 new->fsgid = old->fsgid;
856 new->user = get_uid(old->user);
Eric W. Biederman0093ccb2011-11-16 21:52:53 -0800857 new->user_ns = get_user_ns(new->user_ns);
David Howellsee18d642009-09-02 09:14:21 +0100858 new->group_info = get_group_info(old->group_info);
859
860 new->securebits = old->securebits;
861 new->cap_inheritable = old->cap_inheritable;
862 new->cap_permitted = old->cap_permitted;
863 new->cap_effective = old->cap_effective;
864 new->cap_bset = old->cap_bset;
865
866 new->jit_keyring = old->jit_keyring;
867 new->thread_keyring = key_get(old->thread_keyring);
868 new->tgcred->tgid = old->tgcred->tgid;
869 new->tgcred->process_keyring = key_get(old->tgcred->process_keyring);
870
871 security_transfer_creds(new, old);
872
873 commit_creds(new);
874}