blob: 381411941cc1abbc48a699b1c2c38042f1a05711 [file] [log] [blame]
David Howells76181c12007-10-16 23:29:46 -07001/* Request a key from userspace
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
David Howells76181c12007-10-16 23:29:46 -07003 * Copyright (C) 2004-2007 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.
David Howellsf1a9bad2005-10-07 15:04:52 +010010 *
Randy Dunlapd410fa42011-05-19 15:59:38 -070011 * See Documentation/security/keys-request-key.txt
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 */
13
14#include <linux/module.h>
15#include <linux/sched.h>
16#include <linux/kmod.h>
17#include <linux/err.h>
David Howells3e301482005-06-23 22:00:56 -070018#include <linux/keyctl.h>
Robert P. J. Dayfdb89bc2008-04-29 01:01:32 -070019#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include "internal.h"
21
David Howellse9e349b2008-11-14 10:39:13 +110022#define key_negative_timeout 60 /* default timeout on a negative key's existence */
23
David Howells76181c12007-10-16 23:29:46 -070024/*
25 * wait_on_bit() sleep function for uninterruptible waiting
26 */
27static int key_wait_bit(void *flags)
28{
29 schedule();
30 return 0;
31}
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
David Howells76181c12007-10-16 23:29:46 -070033/*
34 * wait_on_bit() sleep function for interruptible waiting
35 */
36static int key_wait_bit_intr(void *flags)
37{
38 schedule();
39 return signal_pending(current) ? -ERESTARTSYS : 0;
40}
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
David Howells973c9f42011-01-20 16:38:33 +000042/**
43 * complete_request_key - Complete the construction of a key.
44 * @cons: The key construction record.
45 * @error: The success or failute of the construction.
46 *
47 * Complete the attempt to construct a key. The key will be negated
48 * if an error is indicated. The authorisation key will be revoked
49 * unconditionally.
David Howells76181c12007-10-16 23:29:46 -070050 */
51void complete_request_key(struct key_construction *cons, int error)
52{
53 kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
54
55 if (error < 0)
56 key_negate_and_link(cons->key, key_negative_timeout, NULL,
57 cons->authkey);
58 else
59 key_revoke(cons->authkey);
60
61 key_put(cons->key);
62 key_put(cons->authkey);
63 kfree(cons);
64}
65EXPORT_SYMBOL(complete_request_key);
66
David Howells973c9f42011-01-20 16:38:33 +000067/*
68 * Initialise a usermode helper that is going to have a specific session
69 * keyring.
70 *
71 * This is called in context of freshly forked kthread before kernel_execve(),
72 * so we can simply install the desired session_keyring at this point.
73 */
David Howells87966992011-06-17 11:25:59 +010074static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
Oleg Nesterov685bfd22010-05-26 14:43:00 -070075{
Oleg Nesterov685bfd22010-05-26 14:43:00 -070076 struct key *keyring = info->data;
David Howells973c9f42011-01-20 16:38:33 +000077
Oleg Nesterov685bfd22010-05-26 14:43:00 -070078 return install_session_keyring_to_cred(cred, keyring);
79}
80
David Howells973c9f42011-01-20 16:38:33 +000081/*
82 * Clean up a usermode helper with session keyring.
83 */
Oleg Nesterov685bfd22010-05-26 14:43:00 -070084static void umh_keys_cleanup(struct subprocess_info *info)
85{
86 struct key *keyring = info->data;
87 key_put(keyring);
88}
89
David Howells973c9f42011-01-20 16:38:33 +000090/*
91 * Call a usermode helper with a specific session keyring.
92 */
Oleg Nesterov685bfd22010-05-26 14:43:00 -070093static int call_usermodehelper_keys(char *path, char **argv, char **envp,
Oleg Nesterov9d944ef2012-03-23 15:02:48 -070094 struct key *session_keyring, int wait)
Oleg Nesterov685bfd22010-05-26 14:43:00 -070095{
Lucas De Marchi93997f62013-04-30 15:28:05 -070096 struct subprocess_info *info;
97
98 info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL,
99 umh_keys_init, umh_keys_cleanup,
100 session_keyring);
101 if (!info)
102 return -ENOMEM;
103
104 key_get(session_keyring);
105 return call_usermodehelper_exec(info, wait);
Oleg Nesterov685bfd22010-05-26 14:43:00 -0700106}
107
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108/*
David Howells973c9f42011-01-20 16:38:33 +0000109 * Request userspace finish the construction of a key
David Howellsb5f545c2006-01-08 01:02:47 -0800110 * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 */
David Howells76181c12007-10-16 23:29:46 -0700112static int call_sbin_request_key(struct key_construction *cons,
David Howells4e54f082006-06-29 02:24:28 -0700113 const char *op,
114 void *aux)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115{
David Howells86a264a2008-11-14 10:39:18 +1100116 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 key_serial_t prkey, sskey;
David Howells93b4a442010-04-23 13:18:00 -0400118 struct key *key = cons->key, *authkey = cons->authkey, *keyring,
119 *session;
David Howellsb5f545c2006-01-08 01:02:47 -0800120 char *argv[9], *envp[3], uid_str[12], gid_str[12];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 char key_str[12], keyring_str[3][12];
David Howellsb5f545c2006-01-08 01:02:47 -0800122 char desc[20];
David Howells3e301482005-06-23 22:00:56 -0700123 int ret, i;
124
David Howellsb5f545c2006-01-08 01:02:47 -0800125 kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
David Howells3e301482005-06-23 22:00:56 -0700126
David Howells8bbf49762008-11-14 10:39:14 +1100127 ret = install_user_keyrings();
128 if (ret < 0)
129 goto error_alloc;
130
David Howellsb5f545c2006-01-08 01:02:47 -0800131 /* allocate a new session keyring */
132 sprintf(desc, "_req.%u", key->serial);
133
David Howellsd84f4f92008-11-14 10:39:23 +1100134 cred = get_current_cred();
135 keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
David Howells96b5c8f2012-10-02 19:24:56 +0100136 KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
David Howells7e047ef2006-06-26 00:24:50 -0700137 KEY_ALLOC_QUOTA_OVERRUN, NULL);
David Howellsd84f4f92008-11-14 10:39:23 +1100138 put_cred(cred);
David Howellsb5f545c2006-01-08 01:02:47 -0800139 if (IS_ERR(keyring)) {
140 ret = PTR_ERR(keyring);
141 goto error_alloc;
David Howells3e301482005-06-23 22:00:56 -0700142 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
David Howellsb5f545c2006-01-08 01:02:47 -0800144 /* attach the auth key to the session keyring */
David Howells896903c2010-04-30 14:32:23 +0100145 ret = key_link(keyring, authkey);
David Howellsb5f545c2006-01-08 01:02:47 -0800146 if (ret < 0)
147 goto error_link;
148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 /* record the UID and GID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800150 sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid));
151 sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 /* we say which key is under construction */
154 sprintf(key_str, "%d", key->serial);
155
156 /* we specify the process's default keyrings */
157 sprintf(keyring_str[0], "%d",
David Howellsd84f4f92008-11-14 10:39:23 +1100158 cred->thread_keyring ? cred->thread_keyring->serial : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160 prkey = 0;
David Howells3a505972012-10-02 19:24:29 +0100161 if (cred->process_keyring)
162 prkey = cred->process_keyring->serial;
Justin P. Mattock5ad18a02010-06-30 10:39:11 +0100163 sprintf(keyring_str[1], "%d", prkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
David Howells93b4a442010-04-23 13:18:00 -0400165 rcu_read_lock();
David Howells3a505972012-10-02 19:24:29 +0100166 session = rcu_dereference(cred->session_keyring);
David Howells93b4a442010-04-23 13:18:00 -0400167 if (!session)
168 session = cred->user->session_keyring;
169 sskey = session->serial;
170 rcu_read_unlock();
David Howells3e301482005-06-23 22:00:56 -0700171
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 sprintf(keyring_str[2], "%d", sskey);
173
174 /* set up a minimal environment */
175 i = 0;
176 envp[i++] = "HOME=/";
177 envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
178 envp[i] = NULL;
179
180 /* set up the argument list */
181 i = 0;
182 argv[i++] = "/sbin/request-key";
183 argv[i++] = (char *) op;
184 argv[i++] = key_str;
185 argv[i++] = uid_str;
186 argv[i++] = gid_str;
187 argv[i++] = keyring_str[0];
188 argv[i++] = keyring_str[1];
189 argv[i++] = keyring_str[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 argv[i] = NULL;
191
192 /* do it */
Jeremy Fitzhardinge86313c42007-07-17 18:37:03 -0700193 ret = call_usermodehelper_keys(argv[0], argv, envp, keyring,
194 UMH_WAIT_PROC);
David Howells76181c12007-10-16 23:29:46 -0700195 kdebug("usermode -> 0x%x", ret);
196 if (ret >= 0) {
197 /* ret is the exit/wait code */
198 if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) ||
199 key_validate(key) < 0)
200 ret = -ENOKEY;
201 else
202 /* ignore any errors from userspace if the key was
203 * instantiated */
204 ret = 0;
205 }
David Howells3e301482005-06-23 22:00:56 -0700206
David Howellsb5f545c2006-01-08 01:02:47 -0800207error_link:
208 key_put(keyring);
David Howells3e301482005-06-23 22:00:56 -0700209
David Howellsb5f545c2006-01-08 01:02:47 -0800210error_alloc:
David Howells76181c12007-10-16 23:29:46 -0700211 complete_request_key(cons, ret);
David Howellsd84f4f92008-11-14 10:39:23 +1100212 kleave(" = %d", ret);
David Howells3e301482005-06-23 22:00:56 -0700213 return ret;
David Howells76181c12007-10-16 23:29:46 -0700214}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216/*
David Howells973c9f42011-01-20 16:38:33 +0000217 * Call out to userspace for key construction.
218 *
219 * Program failure is ignored in favour of key status.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 */
David Howells4a38e122008-04-29 01:01:24 -0700221static int construct_key(struct key *key, const void *callout_info,
David Howells8bbf49762008-11-14 10:39:14 +1100222 size_t callout_len, void *aux,
223 struct key *dest_keyring)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
David Howells76181c12007-10-16 23:29:46 -0700225 struct key_construction *cons;
David Howellsb5f545c2006-01-08 01:02:47 -0800226 request_key_actor_t actor;
David Howells76181c12007-10-16 23:29:46 -0700227 struct key *authkey;
228 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
David Howells4a38e122008-04-29 01:01:24 -0700230 kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
David Howells3e301482005-06-23 22:00:56 -0700231
David Howells76181c12007-10-16 23:29:46 -0700232 cons = kmalloc(sizeof(*cons), GFP_KERNEL);
233 if (!cons)
234 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
David Howellsb5f545c2006-01-08 01:02:47 -0800236 /* allocate an authorisation key */
David Howells8bbf49762008-11-14 10:39:14 +1100237 authkey = request_key_auth_new(key, callout_info, callout_len,
238 dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -0800239 if (IS_ERR(authkey)) {
David Howells76181c12007-10-16 23:29:46 -0700240 kfree(cons);
David Howellsb5f545c2006-01-08 01:02:47 -0800241 ret = PTR_ERR(authkey);
242 authkey = NULL;
David Howells76181c12007-10-16 23:29:46 -0700243 } else {
244 cons->authkey = key_get(authkey);
245 cons->key = key_get(key);
246
247 /* make the call */
248 actor = call_sbin_request_key;
249 if (key->type->request_key)
250 actor = key->type->request_key;
251
252 ret = actor(cons, "create", aux);
253
254 /* check that the actor called complete_request_key() prior to
255 * returning an error */
256 WARN_ON(ret < 0 &&
257 !test_bit(KEY_FLAG_REVOKED, &authkey->flags));
258 key_put(authkey);
David Howellsb5f545c2006-01-08 01:02:47 -0800259 }
260
David Howells76181c12007-10-16 23:29:46 -0700261 kleave(" = %d", ret);
262 return ret;
263}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265/*
David Howells973c9f42011-01-20 16:38:33 +0000266 * Get the appropriate destination keyring for the request.
267 *
268 * The keyring selected is returned with an extra reference upon it which the
269 * caller must release.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 */
David Howells8bbf49762008-11-14 10:39:14 +1100271static void construct_get_dest_keyring(struct key **_dest_keyring)
David Howells3e301482005-06-23 22:00:56 -0700272{
David Howells8bbf49762008-11-14 10:39:14 +1100273 struct request_key_auth *rka;
David Howellsbb952bb2008-11-14 10:39:20 +1100274 const struct cred *cred = current_cred();
David Howells8bbf49762008-11-14 10:39:14 +1100275 struct key *dest_keyring = *_dest_keyring, *authkey;
David Howells3e301482005-06-23 22:00:56 -0700276
David Howells8bbf49762008-11-14 10:39:14 +1100277 kenter("%p", dest_keyring);
David Howells3e301482005-06-23 22:00:56 -0700278
279 /* find the appropriate keyring */
David Howells8bbf49762008-11-14 10:39:14 +1100280 if (dest_keyring) {
281 /* the caller supplied one */
282 key_get(dest_keyring);
283 } else {
284 /* use a default keyring; falling through the cases until we
285 * find one that we actually have */
David Howellsbb952bb2008-11-14 10:39:20 +1100286 switch (cred->jit_keyring) {
David Howells3e301482005-06-23 22:00:56 -0700287 case KEY_REQKEY_DEFL_DEFAULT:
David Howells8bbf49762008-11-14 10:39:14 +1100288 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100289 if (cred->request_key_auth) {
290 authkey = cred->request_key_auth;
David Howells8bbf49762008-11-14 10:39:14 +1100291 down_read(&authkey->sem);
292 rka = authkey->payload.data;
293 if (!test_bit(KEY_FLAG_REVOKED,
294 &authkey->flags))
295 dest_keyring =
296 key_get(rka->dest_keyring);
297 up_read(&authkey->sem);
298 if (dest_keyring)
299 break;
300 }
301
David Howells3e301482005-06-23 22:00:56 -0700302 case KEY_REQKEY_DEFL_THREAD_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100303 dest_keyring = key_get(cred->thread_keyring);
David Howells3e301482005-06-23 22:00:56 -0700304 if (dest_keyring)
305 break;
306
307 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
David Howells3a505972012-10-02 19:24:29 +0100308 dest_keyring = key_get(cred->process_keyring);
David Howells3e301482005-06-23 22:00:56 -0700309 if (dest_keyring)
310 break;
311
312 case KEY_REQKEY_DEFL_SESSION_KEYRING:
313 rcu_read_lock();
314 dest_keyring = key_get(
David Howells3a505972012-10-02 19:24:29 +0100315 rcu_dereference(cred->session_keyring));
David Howells3e301482005-06-23 22:00:56 -0700316 rcu_read_unlock();
David Howells3e301482005-06-23 22:00:56 -0700317
318 if (dest_keyring)
319 break;
320
321 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
David Howellsb6dff3e2008-11-14 10:39:16 +1100322 dest_keyring =
David Howellsbb952bb2008-11-14 10:39:20 +1100323 key_get(cred->user->session_keyring);
David Howells3e301482005-06-23 22:00:56 -0700324 break;
325
326 case KEY_REQKEY_DEFL_USER_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100327 dest_keyring = key_get(cred->user->uid_keyring);
David Howells3e301482005-06-23 22:00:56 -0700328 break;
329
330 case KEY_REQKEY_DEFL_GROUP_KEYRING:
331 default:
332 BUG();
333 }
334 }
335
David Howells8bbf49762008-11-14 10:39:14 +1100336 *_dest_keyring = dest_keyring;
337 kleave(" [dk %d]", key_serial(dest_keyring));
338 return;
David Howells76181c12007-10-16 23:29:46 -0700339}
David Howells3e301482005-06-23 22:00:56 -0700340
David Howells76181c12007-10-16 23:29:46 -0700341/*
David Howells973c9f42011-01-20 16:38:33 +0000342 * Allocate a new key in under-construction state and attempt to link it in to
343 * the requested keyring.
344 *
345 * May return a key that's already under construction instead if there was a
346 * race between two thread calling request_key().
David Howells76181c12007-10-16 23:29:46 -0700347 */
David Howells4bdf0bc2013-09-24 10:35:15 +0100348static int construct_alloc_key(struct keyring_search_context *ctx,
David Howells76181c12007-10-16 23:29:46 -0700349 struct key *dest_keyring,
350 unsigned long flags,
351 struct key_user *user,
352 struct key **_key)
353{
David Howellsb2a4df22013-09-24 10:35:18 +0100354 struct assoc_array_edit *edit;
David Howells76181c12007-10-16 23:29:46 -0700355 struct key *key;
David Howells96b5c8f2012-10-02 19:24:56 +0100356 key_perm_t perm;
David Howells76181c12007-10-16 23:29:46 -0700357 key_ref_t key_ref;
David Howells2b9e4682010-04-30 14:32:34 +0100358 int ret;
David Howells3e301482005-06-23 22:00:56 -0700359
David Howells4bdf0bc2013-09-24 10:35:15 +0100360 kenter("%s,%s,,,",
361 ctx->index_key.type->name, ctx->index_key.description);
David Howells76181c12007-10-16 23:29:46 -0700362
David Howellsf70e2e02010-04-30 14:32:39 +0100363 *_key = NULL;
David Howells76181c12007-10-16 23:29:46 -0700364 mutex_lock(&user->cons_lock);
365
David Howells96b5c8f2012-10-02 19:24:56 +0100366 perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
367 perm |= KEY_USR_VIEW;
David Howells4bdf0bc2013-09-24 10:35:15 +0100368 if (ctx->index_key.type->read)
David Howells96b5c8f2012-10-02 19:24:56 +0100369 perm |= KEY_POS_READ;
David Howells4bdf0bc2013-09-24 10:35:15 +0100370 if (ctx->index_key.type == &key_type_keyring ||
371 ctx->index_key.type->update)
David Howells96b5c8f2012-10-02 19:24:56 +0100372 perm |= KEY_POS_WRITE;
373
David Howells4bdf0bc2013-09-24 10:35:15 +0100374 key = key_alloc(ctx->index_key.type, ctx->index_key.description,
375 ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
David Howells96b5c8f2012-10-02 19:24:56 +0100376 perm, flags);
David Howells76181c12007-10-16 23:29:46 -0700377 if (IS_ERR(key))
378 goto alloc_failed;
379
380 set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
381
David Howellsf70e2e02010-04-30 14:32:39 +0100382 if (dest_keyring) {
David Howellsb2a4df22013-09-24 10:35:18 +0100383 ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit);
David Howellsf70e2e02010-04-30 14:32:39 +0100384 if (ret < 0)
385 goto link_prealloc_failed;
386 }
David Howells76181c12007-10-16 23:29:46 -0700387
388 /* attach the key to the destination keyring under lock, but we do need
389 * to do another check just in case someone beat us to it whilst we
390 * waited for locks */
391 mutex_lock(&key_construction_mutex);
392
David Howells4bdf0bc2013-09-24 10:35:15 +0100393 key_ref = search_process_keyrings(ctx);
David Howells76181c12007-10-16 23:29:46 -0700394 if (!IS_ERR(key_ref))
395 goto key_already_present;
396
David Howells34574dd2009-04-09 17:14:05 +0100397 if (dest_keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100398 __key_link(key, &edit);
David Howells76181c12007-10-16 23:29:46 -0700399
400 mutex_unlock(&key_construction_mutex);
David Howells34574dd2009-04-09 17:14:05 +0100401 if (dest_keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100402 __key_link_end(dest_keyring, &ctx->index_key, edit);
David Howells76181c12007-10-16 23:29:46 -0700403 mutex_unlock(&user->cons_lock);
404 *_key = key;
405 kleave(" = 0 [%d]", key_serial(key));
406 return 0;
407
David Howells2b9e4682010-04-30 14:32:34 +0100408 /* the key is now present - we tell the caller that we found it by
409 * returning -EINPROGRESS */
David Howells76181c12007-10-16 23:29:46 -0700410key_already_present:
David Howellsf70e2e02010-04-30 14:32:39 +0100411 key_put(key);
David Howells76181c12007-10-16 23:29:46 -0700412 mutex_unlock(&key_construction_mutex);
David Howellsf70e2e02010-04-30 14:32:39 +0100413 key = key_ref_to_ptr(key_ref);
David Howells03449cd2010-04-27 13:13:08 -0700414 if (dest_keyring) {
David Howellsf70e2e02010-04-30 14:32:39 +0100415 ret = __key_link_check_live_key(dest_keyring, key);
416 if (ret == 0)
David Howellsb2a4df22013-09-24 10:35:18 +0100417 __key_link(key, &edit);
418 __key_link_end(dest_keyring, &ctx->index_key, edit);
David Howellsf70e2e02010-04-30 14:32:39 +0100419 if (ret < 0)
420 goto link_check_failed;
David Howells03449cd2010-04-27 13:13:08 -0700421 }
David Howells76181c12007-10-16 23:29:46 -0700422 mutex_unlock(&user->cons_lock);
David Howellsf70e2e02010-04-30 14:32:39 +0100423 *_key = key;
David Howells76181c12007-10-16 23:29:46 -0700424 kleave(" = -EINPROGRESS [%d]", key_serial(key));
425 return -EINPROGRESS;
426
David Howellsf70e2e02010-04-30 14:32:39 +0100427link_check_failed:
428 mutex_unlock(&user->cons_lock);
429 key_put(key);
430 kleave(" = %d [linkcheck]", ret);
431 return ret;
432
433link_prealloc_failed:
David Howellsf70e2e02010-04-30 14:32:39 +0100434 mutex_unlock(&user->cons_lock);
435 kleave(" = %d [prelink]", ret);
436 return ret;
437
David Howells76181c12007-10-16 23:29:46 -0700438alloc_failed:
439 mutex_unlock(&user->cons_lock);
David Howells76181c12007-10-16 23:29:46 -0700440 kleave(" = %ld", PTR_ERR(key));
441 return PTR_ERR(key);
442}
443
444/*
David Howells973c9f42011-01-20 16:38:33 +0000445 * Commence key construction.
David Howells76181c12007-10-16 23:29:46 -0700446 */
David Howells4bdf0bc2013-09-24 10:35:15 +0100447static struct key *construct_key_and_link(struct keyring_search_context *ctx,
David Howells76181c12007-10-16 23:29:46 -0700448 const char *callout_info,
David Howells4a38e122008-04-29 01:01:24 -0700449 size_t callout_len,
David Howells76181c12007-10-16 23:29:46 -0700450 void *aux,
451 struct key *dest_keyring,
452 unsigned long flags)
453{
454 struct key_user *user;
455 struct key *key;
456 int ret;
457
David Howellsd84f4f92008-11-14 10:39:23 +1100458 kenter("");
459
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800460 user = key_user_lookup(current_fsuid());
David Howells76181c12007-10-16 23:29:46 -0700461 if (!user)
462 return ERR_PTR(-ENOMEM);
463
David Howells8bbf49762008-11-14 10:39:14 +1100464 construct_get_dest_keyring(&dest_keyring);
465
David Howells4bdf0bc2013-09-24 10:35:15 +0100466 ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
David Howells76181c12007-10-16 23:29:46 -0700467 key_user_put(user);
468
469 if (ret == 0) {
David Howells8bbf49762008-11-14 10:39:14 +1100470 ret = construct_key(key, callout_info, callout_len, aux,
471 dest_keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100472 if (ret < 0) {
473 kdebug("cons failed");
David Howells76181c12007-10-16 23:29:46 -0700474 goto construction_failed;
David Howellsd84f4f92008-11-14 10:39:23 +1100475 }
David Howells2b9e4682010-04-30 14:32:34 +0100476 } else if (ret == -EINPROGRESS) {
477 ret = 0;
478 } else {
David Howellsb1d7dd82011-06-21 14:32:05 +0100479 goto couldnt_alloc_key;
David Howells76181c12007-10-16 23:29:46 -0700480 }
481
David Howells8bbf49762008-11-14 10:39:14 +1100482 key_put(dest_keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100483 kleave(" = key %d", key_serial(key));
David Howells76181c12007-10-16 23:29:46 -0700484 return key;
485
486construction_failed:
487 key_negate_and_link(key, key_negative_timeout, NULL, NULL);
488 key_put(key);
David Howellsb1d7dd82011-06-21 14:32:05 +0100489couldnt_alloc_key:
David Howells8bbf49762008-11-14 10:39:14 +1100490 key_put(dest_keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100491 kleave(" = %d", ret);
David Howells76181c12007-10-16 23:29:46 -0700492 return ERR_PTR(ret);
493}
494
David Howells973c9f42011-01-20 16:38:33 +0000495/**
496 * request_key_and_link - Request a key and cache it in a keyring.
497 * @type: The type of key we want.
498 * @description: The searchable description of the key.
499 * @callout_info: The data to pass to the instantiation upcall (or NULL).
500 * @callout_len: The length of callout_info.
501 * @aux: Auxiliary data for the upcall.
502 * @dest_keyring: Where to cache the key.
503 * @flags: Flags to key_alloc().
504 *
505 * A key matching the specified criteria is searched for in the process's
506 * keyrings and returned with its usage count incremented if found. Otherwise,
507 * if callout_info is not NULL, a key will be allocated and some service
508 * (probably in userspace) will be asked to instantiate it.
509 *
510 * If successfully found or created, the key will be linked to the destination
511 * keyring if one is provided.
512 *
513 * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED
514 * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was
515 * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT
516 * if insufficient key quota was available to create a new key; or -ENOMEM if
517 * insufficient memory was available.
518 *
519 * If the returned key was created, then it may still be under construction,
520 * and wait_for_key_construction() should be used to wait for that to complete.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 */
David Howells3e301482005-06-23 22:00:56 -0700522struct key *request_key_and_link(struct key_type *type,
523 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700524 const void *callout_info,
525 size_t callout_len,
David Howells4e54f082006-06-29 02:24:28 -0700526 void *aux,
David Howells7e047ef2006-06-26 00:24:50 -0700527 struct key *dest_keyring,
528 unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529{
David Howells4bdf0bc2013-09-24 10:35:15 +0100530 struct keyring_search_context ctx = {
531 .index_key.type = type,
532 .index_key.description = description,
533 .cred = current_cred(),
534 .match = type->match,
535 .match_data = description,
536 .flags = KEYRING_SEARCH_LOOKUP_DIRECT,
537 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100539 key_ref_t key_ref;
David Howells2b9e4682010-04-30 14:32:34 +0100540 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541
David Howells4a38e122008-04-29 01:01:24 -0700542 kenter("%s,%s,%p,%zu,%p,%p,%lx",
David Howells4bdf0bc2013-09-24 10:35:15 +0100543 ctx.index_key.type->name, ctx.index_key.description,
544 callout_info, callout_len, aux, dest_keyring, flags);
David Howells3e301482005-06-23 22:00:56 -0700545
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 /* search all the process keyrings for a key */
David Howells4bdf0bc2013-09-24 10:35:15 +0100547 key_ref = search_process_keyrings(&ctx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
David Howells664cceb2005-09-28 17:03:15 +0100549 if (!IS_ERR(key_ref)) {
550 key = key_ref_to_ptr(key_ref);
David Howells03449cd2010-04-27 13:13:08 -0700551 if (dest_keyring) {
552 construct_get_dest_keyring(&dest_keyring);
David Howells2b9e4682010-04-30 14:32:34 +0100553 ret = key_link(dest_keyring, key);
David Howells03449cd2010-04-27 13:13:08 -0700554 key_put(dest_keyring);
David Howells2b9e4682010-04-30 14:32:34 +0100555 if (ret < 0) {
556 key_put(key);
557 key = ERR_PTR(ret);
558 goto error;
559 }
David Howells03449cd2010-04-27 13:13:08 -0700560 }
David Howells76181c12007-10-16 23:29:46 -0700561 } else if (PTR_ERR(key_ref) != -EAGAIN) {
David Howellse231c2e2008-02-07 00:15:26 -0800562 key = ERR_CAST(key_ref);
David Howells76181c12007-10-16 23:29:46 -0700563 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 /* the search failed, but the keyrings were searchable, so we
565 * should consult userspace if we can */
566 key = ERR_PTR(-ENOKEY);
567 if (!callout_info)
568 goto error;
569
David Howells4bdf0bc2013-09-24 10:35:15 +0100570 key = construct_key_and_link(&ctx, callout_info, callout_len,
571 aux, dest_keyring, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 }
573
David Howells3e301482005-06-23 22:00:56 -0700574error:
575 kleave(" = %p", key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 return key;
David Howells76181c12007-10-16 23:29:46 -0700577}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
David Howells973c9f42011-01-20 16:38:33 +0000579/**
580 * wait_for_key_construction - Wait for construction of a key to complete
581 * @key: The key being waited for.
582 * @intr: Whether to wait interruptibly.
583 *
584 * Wait for a key to finish being constructed.
585 *
586 * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY
587 * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was
588 * revoked or expired.
David Howells76181c12007-10-16 23:29:46 -0700589 */
590int wait_for_key_construction(struct key *key, bool intr)
591{
592 int ret;
David Howells3e301482005-06-23 22:00:56 -0700593
David Howells76181c12007-10-16 23:29:46 -0700594 ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
595 intr ? key_wait_bit_intr : key_wait_bit,
596 intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
597 if (ret < 0)
598 return ret;
David Howells74792b02013-10-30 11:15:24 +0000599 if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
600 smp_rmb();
David Howellsfdd1b942011-03-07 15:06:09 +0000601 return key->type_data.reject_error;
David Howells74792b02013-10-30 11:15:24 +0000602 }
David Howells76181c12007-10-16 23:29:46 -0700603 return key_validate(key);
604}
605EXPORT_SYMBOL(wait_for_key_construction);
David Howells3e301482005-06-23 22:00:56 -0700606
David Howells973c9f42011-01-20 16:38:33 +0000607/**
608 * request_key - Request a key and wait for construction
609 * @type: Type of key.
610 * @description: The searchable description of the key.
611 * @callout_info: The data to pass to the instantiation upcall (or NULL).
612 *
613 * As for request_key_and_link() except that it does not add the returned key
614 * to a keyring if found, new keys are always allocated in the user's quota,
615 * the callout_info must be a NUL-terminated string and no auxiliary data can
616 * be passed.
617 *
618 * Furthermore, it then works as wait_for_key_construction() to wait for the
619 * completion of keys undergoing construction with a non-interruptible wait.
David Howells3e301482005-06-23 22:00:56 -0700620 */
621struct key *request_key(struct key_type *type,
622 const char *description,
623 const char *callout_info)
624{
David Howells76181c12007-10-16 23:29:46 -0700625 struct key *key;
David Howells4a38e122008-04-29 01:01:24 -0700626 size_t callout_len = 0;
David Howells76181c12007-10-16 23:29:46 -0700627 int ret;
David Howells3e301482005-06-23 22:00:56 -0700628
David Howells4a38e122008-04-29 01:01:24 -0700629 if (callout_info)
630 callout_len = strlen(callout_info);
631 key = request_key_and_link(type, description, callout_info, callout_len,
632 NULL, NULL, KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700633 if (!IS_ERR(key)) {
634 ret = wait_for_key_construction(key, false);
635 if (ret < 0) {
636 key_put(key);
637 return ERR_PTR(ret);
638 }
639 }
640 return key;
641}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642EXPORT_SYMBOL(request_key);
David Howells4e54f082006-06-29 02:24:28 -0700643
David Howells973c9f42011-01-20 16:38:33 +0000644/**
645 * request_key_with_auxdata - Request a key with auxiliary data for the upcaller
646 * @type: The type of key we want.
647 * @description: The searchable description of the key.
648 * @callout_info: The data to pass to the instantiation upcall (or NULL).
649 * @callout_len: The length of callout_info.
650 * @aux: Auxiliary data for the upcall.
651 *
652 * As for request_key_and_link() except that it does not add the returned key
653 * to a keyring if found and new keys are always allocated in the user's quota.
654 *
655 * Furthermore, it then works as wait_for_key_construction() to wait for the
656 * completion of keys undergoing construction with a non-interruptible wait.
David Howells4e54f082006-06-29 02:24:28 -0700657 */
658struct key *request_key_with_auxdata(struct key_type *type,
659 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700660 const void *callout_info,
661 size_t callout_len,
David Howells4e54f082006-06-29 02:24:28 -0700662 void *aux)
663{
David Howells76181c12007-10-16 23:29:46 -0700664 struct key *key;
665 int ret;
666
David Howells4a38e122008-04-29 01:01:24 -0700667 key = request_key_and_link(type, description, callout_info, callout_len,
668 aux, NULL, KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700669 if (!IS_ERR(key)) {
670 ret = wait_for_key_construction(key, false);
671 if (ret < 0) {
672 key_put(key);
673 return ERR_PTR(ret);
674 }
675 }
676 return key;
677}
678EXPORT_SYMBOL(request_key_with_auxdata);
679
680/*
David Howells973c9f42011-01-20 16:38:33 +0000681 * request_key_async - Request a key (allow async construction)
682 * @type: Type of key.
683 * @description: The searchable description of the key.
684 * @callout_info: The data to pass to the instantiation upcall (or NULL).
685 * @callout_len: The length of callout_info.
686 *
687 * As for request_key_and_link() except that it does not add the returned key
688 * to a keyring if found, new keys are always allocated in the user's quota and
689 * no auxiliary data can be passed.
690 *
691 * The caller should call wait_for_key_construction() to wait for the
692 * completion of the returned key if it is still undergoing construction.
David Howells76181c12007-10-16 23:29:46 -0700693 */
694struct key *request_key_async(struct key_type *type,
695 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700696 const void *callout_info,
697 size_t callout_len)
David Howells76181c12007-10-16 23:29:46 -0700698{
David Howells4a38e122008-04-29 01:01:24 -0700699 return request_key_and_link(type, description, callout_info,
700 callout_len, NULL, NULL,
701 KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700702}
703EXPORT_SYMBOL(request_key_async);
704
705/*
706 * request a key with auxiliary data for the upcaller (allow async construction)
David Howells973c9f42011-01-20 16:38:33 +0000707 * @type: Type of key.
708 * @description: The searchable description of the key.
709 * @callout_info: The data to pass to the instantiation upcall (or NULL).
710 * @callout_len: The length of callout_info.
711 * @aux: Auxiliary data for the upcall.
712 *
713 * As for request_key_and_link() except that it does not add the returned key
714 * to a keyring if found and new keys are always allocated in the user's quota.
715 *
716 * The caller should call wait_for_key_construction() to wait for the
717 * completion of the returned key if it is still undergoing construction.
David Howells76181c12007-10-16 23:29:46 -0700718 */
719struct key *request_key_async_with_auxdata(struct key_type *type,
720 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700721 const void *callout_info,
722 size_t callout_len,
David Howells76181c12007-10-16 23:29:46 -0700723 void *aux)
724{
David Howells4a38e122008-04-29 01:01:24 -0700725 return request_key_and_link(type, description, callout_info,
726 callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700727}
728EXPORT_SYMBOL(request_key_async_with_auxdata);