David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 1 | /* Keyring handling |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 3 | * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * 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> |
| 15 | #include <linux/slab.h> |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 16 | #include <linux/security.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/seq_file.h> |
| 18 | #include <linux/err.h> |
David Howells | e9e349b | 2008-11-14 10:39:13 +1100 | [diff] [blame] | 19 | #include <keys/keyring-type.h> |
Chihau Chau | 512ea3b | 2010-03-08 20:11:34 -0300 | [diff] [blame] | 20 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include "internal.h" |
| 22 | |
David Howells | f0641cb | 2010-04-30 14:32:18 +0100 | [diff] [blame] | 23 | #define rcu_dereference_locked_keyring(keyring) \ |
| 24 | (rcu_dereference_protected( \ |
| 25 | (keyring)->payload.subscriptions, \ |
| 26 | rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem))) |
| 27 | |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 28 | #define rcu_deref_link_locked(klist, index, keyring) \ |
| 29 | (rcu_dereference_protected( \ |
| 30 | (klist)->keys[index], \ |
| 31 | rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem))) |
| 32 | |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 33 | #define MAX_KEYRING_LINKS \ |
| 34 | min_t(size_t, USHRT_MAX - 1, \ |
| 35 | ((PAGE_SIZE - sizeof(struct keyring_list)) / sizeof(struct key *))) |
| 36 | |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 37 | #define KEY_LINK_FIXQUOTA 1UL |
| 38 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 40 | * When plumbing the depths of the key tree, this sets a hard limit |
| 41 | * set on how deep we're willing to go. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | */ |
| 43 | #define KEYRING_SEARCH_MAX_DEPTH 6 |
| 44 | |
| 45 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 46 | * We keep all named keyrings in a hash to speed looking them up. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | */ |
| 48 | #define KEYRING_NAME_HASH_SIZE (1 << 5) |
| 49 | |
| 50 | static struct list_head keyring_name_hash[KEYRING_NAME_HASH_SIZE]; |
| 51 | static DEFINE_RWLOCK(keyring_name_lock); |
| 52 | |
| 53 | static inline unsigned keyring_hash(const char *desc) |
| 54 | { |
| 55 | unsigned bucket = 0; |
| 56 | |
| 57 | for (; *desc; desc++) |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 58 | bucket += (unsigned char)*desc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
| 60 | return bucket & (KEYRING_NAME_HASH_SIZE - 1); |
| 61 | } |
| 62 | |
| 63 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 64 | * The keyring key type definition. Keyrings are simply keys of this type and |
| 65 | * can be treated as ordinary keys in addition to having their own special |
| 66 | * operations. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | */ |
| 68 | static int keyring_instantiate(struct key *keyring, |
| 69 | const void *data, size_t datalen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | static int keyring_match(const struct key *keyring, const void *criterion); |
David Howells | 31204ed | 2006-06-26 00:24:51 -0700 | [diff] [blame] | 71 | static void keyring_revoke(struct key *keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | static void keyring_destroy(struct key *keyring); |
| 73 | static void keyring_describe(const struct key *keyring, struct seq_file *m); |
| 74 | static long keyring_read(const struct key *keyring, |
| 75 | char __user *buffer, size_t buflen); |
| 76 | |
| 77 | struct key_type key_type_keyring = { |
| 78 | .name = "keyring", |
| 79 | .def_datalen = sizeof(struct keyring_list), |
| 80 | .instantiate = keyring_instantiate, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | .match = keyring_match, |
David Howells | 31204ed | 2006-06-26 00:24:51 -0700 | [diff] [blame] | 82 | .revoke = keyring_revoke, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | .destroy = keyring_destroy, |
| 84 | .describe = keyring_describe, |
| 85 | .read = keyring_read, |
| 86 | }; |
David Howells | 7318226 | 2007-04-26 15:46:23 -0700 | [diff] [blame] | 87 | EXPORT_SYMBOL(key_type_keyring); |
| 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 90 | * Semaphore to serialise link/link calls to prevent two link calls in parallel |
| 91 | * introducing a cycle. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | */ |
Adrian Bunk | 1ae8f40 | 2006-01-06 00:11:25 -0800 | [diff] [blame] | 93 | static DECLARE_RWSEM(keyring_serialise_link_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 96 | * Publish the name of a keyring so that it can be found by name (if it has |
| 97 | * one). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | */ |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 99 | static void keyring_publish_name(struct key *keyring) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | { |
| 101 | int bucket; |
| 102 | |
| 103 | if (keyring->description) { |
| 104 | bucket = keyring_hash(keyring->description); |
| 105 | |
| 106 | write_lock(&keyring_name_lock); |
| 107 | |
| 108 | if (!keyring_name_hash[bucket].next) |
| 109 | INIT_LIST_HEAD(&keyring_name_hash[bucket]); |
| 110 | |
| 111 | list_add_tail(&keyring->type_data.link, |
| 112 | &keyring_name_hash[bucket]); |
| 113 | |
| 114 | write_unlock(&keyring_name_lock); |
| 115 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 116 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 119 | * Initialise a keyring. |
| 120 | * |
| 121 | * Returns 0 on success, -EINVAL if given any data. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | */ |
| 123 | static int keyring_instantiate(struct key *keyring, |
| 124 | const void *data, size_t datalen) |
| 125 | { |
| 126 | int ret; |
| 127 | |
| 128 | ret = -EINVAL; |
| 129 | if (datalen == 0) { |
| 130 | /* make the keyring available by name if it has one */ |
| 131 | keyring_publish_name(keyring); |
| 132 | ret = 0; |
| 133 | } |
| 134 | |
| 135 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 136 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 139 | * Match keyrings on their name |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | */ |
| 141 | static int keyring_match(const struct key *keyring, const void *description) |
| 142 | { |
| 143 | return keyring->description && |
| 144 | strcmp(keyring->description, description) == 0; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 145 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 148 | * Clean up a keyring when it is destroyed. Unpublish its name if it had one |
| 149 | * and dispose of its data. |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 150 | * |
| 151 | * The garbage collector detects the final key_put(), removes the keyring from |
| 152 | * the serial number tree and then does RCU synchronisation before coming here, |
| 153 | * so we shouldn't need to worry about code poking around here with the RCU |
| 154 | * readlock held by this time. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | */ |
| 156 | static void keyring_destroy(struct key *keyring) |
| 157 | { |
| 158 | struct keyring_list *klist; |
| 159 | int loop; |
| 160 | |
| 161 | if (keyring->description) { |
| 162 | write_lock(&keyring_name_lock); |
David Howells | 94efe72 | 2005-08-04 13:07:07 -0700 | [diff] [blame] | 163 | |
| 164 | if (keyring->type_data.link.next != NULL && |
| 165 | !list_empty(&keyring->type_data.link)) |
| 166 | list_del(&keyring->type_data.link); |
| 167 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | write_unlock(&keyring_name_lock); |
| 169 | } |
| 170 | |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 171 | klist = rcu_access_pointer(keyring->payload.subscriptions); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | if (klist) { |
| 173 | for (loop = klist->nkeys - 1; loop >= 0; loop--) |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 174 | key_put(rcu_access_pointer(klist->keys[loop])); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | kfree(klist); |
| 176 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 177 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 180 | * Describe a keyring for /proc. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | */ |
| 182 | static void keyring_describe(const struct key *keyring, struct seq_file *m) |
| 183 | { |
| 184 | struct keyring_list *klist; |
| 185 | |
wzt.wzt@gmail.com | c856347 | 2010-03-04 21:26:23 +0800 | [diff] [blame] | 186 | if (keyring->description) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | seq_puts(m, keyring->description); |
wzt.wzt@gmail.com | c856347 | 2010-03-04 21:26:23 +0800 | [diff] [blame] | 188 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | seq_puts(m, "[anon]"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 191 | if (key_is_instantiated(keyring)) { |
| 192 | rcu_read_lock(); |
| 193 | klist = rcu_dereference(keyring->payload.subscriptions); |
| 194 | if (klist) |
| 195 | seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys); |
| 196 | else |
| 197 | seq_puts(m, ": empty"); |
| 198 | rcu_read_unlock(); |
| 199 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 200 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 203 | * Read a list of key IDs from the keyring's contents in binary form |
| 204 | * |
| 205 | * The keyring's semaphore is read-locked by the caller. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | */ |
| 207 | static long keyring_read(const struct key *keyring, |
| 208 | char __user *buffer, size_t buflen) |
| 209 | { |
| 210 | struct keyring_list *klist; |
| 211 | struct key *key; |
| 212 | size_t qty, tmp; |
| 213 | int loop, ret; |
| 214 | |
| 215 | ret = 0; |
David Howells | f0641cb | 2010-04-30 14:32:18 +0100 | [diff] [blame] | 216 | klist = rcu_dereference_locked_keyring(keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | if (klist) { |
| 218 | /* calculate how much data we could return */ |
| 219 | qty = klist->nkeys * sizeof(key_serial_t); |
| 220 | |
| 221 | if (buffer && buflen > 0) { |
| 222 | if (buflen > qty) |
| 223 | buflen = qty; |
| 224 | |
| 225 | /* copy the IDs of the subscribed keys into the |
| 226 | * buffer */ |
| 227 | ret = -EFAULT; |
| 228 | |
| 229 | for (loop = 0; loop < klist->nkeys; loop++) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 230 | key = rcu_deref_link_locked(klist, loop, |
| 231 | keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | |
| 233 | tmp = sizeof(key_serial_t); |
| 234 | if (tmp > buflen) |
| 235 | tmp = buflen; |
| 236 | |
| 237 | if (copy_to_user(buffer, |
| 238 | &key->serial, |
| 239 | tmp) != 0) |
| 240 | goto error; |
| 241 | |
| 242 | buflen -= tmp; |
| 243 | if (buflen == 0) |
| 244 | break; |
| 245 | buffer += tmp; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | ret = qty; |
| 250 | } |
| 251 | |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 252 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 254 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 257 | * Allocate a keyring and link into the destination keyring. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | */ |
| 259 | struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 260 | const struct cred *cred, unsigned long flags, |
Michael LeMay | d720024 | 2006-06-22 14:47:17 -0700 | [diff] [blame] | 261 | struct key *dest) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | { |
| 263 | struct key *keyring; |
| 264 | int ret; |
| 265 | |
| 266 | keyring = key_alloc(&key_type_keyring, description, |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 267 | uid, gid, cred, |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 268 | (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 269 | flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | |
| 271 | if (!IS_ERR(keyring)) { |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 272 | ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | if (ret < 0) { |
| 274 | key_put(keyring); |
| 275 | keyring = ERR_PTR(ret); |
| 276 | } |
| 277 | } |
| 278 | |
| 279 | return keyring; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 280 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 282 | /** |
| 283 | * keyring_search_aux - Search a keyring tree for a key matching some criteria |
| 284 | * @keyring_ref: A pointer to the keyring with possession indicator. |
| 285 | * @cred: The credentials to use for permissions checks. |
| 286 | * @type: The type of key to search for. |
| 287 | * @description: Parameter for @match. |
| 288 | * @match: Function to rule on whether or not a key is the one required. |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 289 | * @no_state_check: Don't check if a matching key is bad |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 290 | * |
| 291 | * Search the supplied keyring tree for a key that matches the criteria given. |
| 292 | * The root keyring and any linked keyrings must grant Search permission to the |
| 293 | * caller to be searchable and keys can only be found if they too grant Search |
| 294 | * to the caller. The possession flag on the root keyring pointer controls use |
| 295 | * of the possessor bits in permissions checking of the entire tree. In |
| 296 | * addition, the LSM gets to forbid keyring searches and key matches. |
| 297 | * |
| 298 | * The search is performed as a breadth-then-depth search up to the prescribed |
| 299 | * limit (KEYRING_SEARCH_MAX_DEPTH). |
| 300 | * |
| 301 | * Keys are matched to the type provided and are then filtered by the match |
| 302 | * function, which is given the description to use in any way it sees fit. The |
| 303 | * match function may use any attributes of a key that it wishes to to |
| 304 | * determine the match. Normally the match function from the key type would be |
| 305 | * used. |
| 306 | * |
| 307 | * RCU is used to prevent the keyring key lists from disappearing without the |
| 308 | * need to take lots of locks. |
| 309 | * |
| 310 | * Returns a pointer to the found key and increments the key usage count if |
| 311 | * successful; -EAGAIN if no matching keys were found, or if expired or revoked |
| 312 | * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the |
| 313 | * specified keyring wasn't a keyring. |
| 314 | * |
| 315 | * In the case of a successful return, the possession attribute from |
| 316 | * @keyring_ref is propagated to the returned key reference. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 318 | key_ref_t keyring_search_aux(key_ref_t keyring_ref, |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 319 | const struct cred *cred, |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 320 | struct key_type *type, |
| 321 | const void *description, |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 322 | key_match_func_t match, |
| 323 | bool no_state_check) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | { |
| 325 | struct { |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 326 | /* Need a separate keylist pointer for RCU purposes */ |
| 327 | struct key *keyring; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 328 | struct keyring_list *keylist; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | int kix; |
| 330 | } stack[KEYRING_SEARCH_MAX_DEPTH]; |
| 331 | |
| 332 | struct keyring_list *keylist; |
| 333 | struct timespec now; |
Kevin Coffman | dceba99 | 2008-04-29 01:01:22 -0700 | [diff] [blame] | 334 | unsigned long possessed, kflags; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 335 | struct key *keyring, *key; |
| 336 | key_ref_t key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | long err; |
David Howells | efde8b6 | 2012-01-17 20:39:40 +0000 | [diff] [blame] | 338 | int sp, nkeys, kix; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 340 | keyring = key_ref_to_ptr(keyring_ref); |
| 341 | possessed = is_key_possessed(keyring_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | key_check(keyring); |
| 343 | |
| 344 | /* top keyring must have search permission to begin the search */ |
Chihau Chau | 512ea3b | 2010-03-08 20:11:34 -0300 | [diff] [blame] | 345 | err = key_task_permission(keyring_ref, cred, KEY_SEARCH); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 346 | if (err < 0) { |
| 347 | key_ref = ERR_PTR(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | goto error; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 349 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 351 | key_ref = ERR_PTR(-ENOTDIR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | if (keyring->type != &key_type_keyring) |
| 353 | goto error; |
| 354 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 355 | rcu_read_lock(); |
| 356 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | now = current_kernel_time(); |
| 358 | err = -EAGAIN; |
| 359 | sp = 0; |
| 360 | |
Kevin Coffman | dceba99 | 2008-04-29 01:01:22 -0700 | [diff] [blame] | 361 | /* firstly we should check to see if this top-level keyring is what we |
| 362 | * are looking for */ |
| 363 | key_ref = ERR_PTR(-EAGAIN); |
| 364 | kflags = keyring->flags; |
| 365 | if (keyring->type == type && match(keyring, description)) { |
| 366 | key = keyring; |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 367 | if (no_state_check) |
| 368 | goto found; |
Kevin Coffman | dceba99 | 2008-04-29 01:01:22 -0700 | [diff] [blame] | 369 | |
| 370 | /* check it isn't negative and hasn't expired or been |
| 371 | * revoked */ |
| 372 | if (kflags & (1 << KEY_FLAG_REVOKED)) |
| 373 | goto error_2; |
| 374 | if (key->expiry && now.tv_sec >= key->expiry) |
| 375 | goto error_2; |
David Howells | fdd1b94 | 2011-03-07 15:06:09 +0000 | [diff] [blame] | 376 | key_ref = ERR_PTR(key->type_data.reject_error); |
Kevin Coffman | dceba99 | 2008-04-29 01:01:22 -0700 | [diff] [blame] | 377 | if (kflags & (1 << KEY_FLAG_NEGATIVE)) |
| 378 | goto error_2; |
| 379 | goto found; |
| 380 | } |
| 381 | |
| 382 | /* otherwise, the top keyring must not be revoked, expired, or |
| 383 | * negatively instantiated if we are to search it */ |
| 384 | key_ref = ERR_PTR(-EAGAIN); |
| 385 | if (kflags & ((1 << KEY_FLAG_REVOKED) | (1 << KEY_FLAG_NEGATIVE)) || |
| 386 | (keyring->expiry && now.tv_sec >= keyring->expiry)) |
| 387 | goto error_2; |
| 388 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | /* start processing a new keyring */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 390 | descend: |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 391 | if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | goto not_this_keyring; |
| 393 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 394 | keylist = rcu_dereference(keyring->payload.subscriptions); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | if (!keylist) |
| 396 | goto not_this_keyring; |
| 397 | |
| 398 | /* iterate through the keys in this keyring first */ |
David Howells | efde8b6 | 2012-01-17 20:39:40 +0000 | [diff] [blame] | 399 | nkeys = keylist->nkeys; |
| 400 | smp_rmb(); |
| 401 | for (kix = 0; kix < nkeys; kix++) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 402 | key = rcu_dereference(keylist->keys[kix]); |
Kevin Coffman | dceba99 | 2008-04-29 01:01:22 -0700 | [diff] [blame] | 403 | kflags = key->flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | |
| 405 | /* ignore keys not of this type */ |
| 406 | if (key->type != type) |
| 407 | continue; |
| 408 | |
| 409 | /* skip revoked keys and expired keys */ |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 410 | if (!no_state_check) { |
| 411 | if (kflags & (1 << KEY_FLAG_REVOKED)) |
| 412 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 414 | if (key->expiry && now.tv_sec >= key->expiry) |
| 415 | continue; |
| 416 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
| 418 | /* keys that don't match */ |
| 419 | if (!match(key, description)) |
| 420 | continue; |
| 421 | |
| 422 | /* key must have search permissions */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 423 | if (key_task_permission(make_key_ref(key, possessed), |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 424 | cred, KEY_SEARCH) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | continue; |
| 426 | |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 427 | if (no_state_check) |
| 428 | goto found; |
| 429 | |
Kevin Coffman | dceba99 | 2008-04-29 01:01:22 -0700 | [diff] [blame] | 430 | /* we set a different error code if we pass a negative key */ |
| 431 | if (kflags & (1 << KEY_FLAG_NEGATIVE)) { |
David Howells | fdd1b94 | 2011-03-07 15:06:09 +0000 | [diff] [blame] | 432 | err = key->type_data.reject_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | continue; |
| 434 | } |
| 435 | |
| 436 | goto found; |
| 437 | } |
| 438 | |
| 439 | /* search through the keyrings nested in this one */ |
| 440 | kix = 0; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 441 | ascend: |
David Howells | efde8b6 | 2012-01-17 20:39:40 +0000 | [diff] [blame] | 442 | nkeys = keylist->nkeys; |
| 443 | smp_rmb(); |
| 444 | for (; kix < nkeys; kix++) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 445 | key = rcu_dereference(keylist->keys[kix]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | if (key->type != &key_type_keyring) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 447 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | |
| 449 | /* recursively search nested keyrings |
| 450 | * - only search keyrings for which we have search permission |
| 451 | */ |
| 452 | if (sp >= KEYRING_SEARCH_MAX_DEPTH) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 453 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
David Howells | 0f6ed7c | 2005-11-07 00:59:30 -0800 | [diff] [blame] | 455 | if (key_task_permission(make_key_ref(key, possessed), |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 456 | cred, KEY_SEARCH) < 0) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 457 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | |
| 459 | /* stack the current position */ |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 460 | stack[sp].keyring = keyring; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 461 | stack[sp].keylist = keylist; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | stack[sp].kix = kix; |
| 463 | sp++; |
| 464 | |
| 465 | /* begin again with the new keyring */ |
| 466 | keyring = key; |
| 467 | goto descend; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | } |
| 469 | |
| 470 | /* the keyring we're looking at was disqualified or didn't contain a |
| 471 | * matching key */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 472 | not_this_keyring: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | if (sp > 0) { |
| 474 | /* resume the processing of a keyring higher up in the tree */ |
| 475 | sp--; |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 476 | keyring = stack[sp].keyring; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 477 | keylist = stack[sp].keylist; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | kix = stack[sp].kix + 1; |
| 479 | goto ascend; |
| 480 | } |
| 481 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 482 | key_ref = ERR_PTR(err); |
| 483 | goto error_2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | |
| 485 | /* we found a viable match */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 486 | found: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | atomic_inc(&key->usage); |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 488 | key->last_used_at = now.tv_sec; |
| 489 | keyring->last_used_at = now.tv_sec; |
| 490 | while (sp > 0) |
| 491 | stack[--sp].keyring->last_used_at = now.tv_sec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | key_check(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 493 | key_ref = make_key_ref(key, possessed); |
| 494 | error_2: |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 495 | rcu_read_unlock(); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 496 | error: |
| 497 | return key_ref; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 498 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 500 | /** |
| 501 | * keyring_search - Search the supplied keyring tree for a matching key |
| 502 | * @keyring: The root of the keyring tree to be searched. |
| 503 | * @type: The type of keyring we want to find. |
| 504 | * @description: The name of the keyring we want to find. |
| 505 | * |
| 506 | * As keyring_search_aux() above, but using the current task's credentials and |
| 507 | * type's default matching function. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 509 | key_ref_t keyring_search(key_ref_t keyring, |
| 510 | struct key_type *type, |
| 511 | const char *description) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | { |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 513 | if (!type->match) |
| 514 | return ERR_PTR(-ENOKEY); |
| 515 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 516 | return keyring_search_aux(keyring, current->cred, |
David Howells | 78b7280 | 2011-03-11 17:57:23 +0000 | [diff] [blame] | 517 | type, description, type->match, false); |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 518 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | EXPORT_SYMBOL(keyring_search); |
| 520 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 522 | * Search the given keyring only (no recursion). |
| 523 | * |
| 524 | * The caller must guarantee that the keyring is a keyring and that the |
| 525 | * permission is granted to search the keyring as no check is made here. |
| 526 | * |
| 527 | * RCU is used to make it unnecessary to lock the keyring key list here. |
| 528 | * |
| 529 | * Returns a pointer to the found key with usage count incremented if |
| 530 | * successful and returns -ENOKEY if not found. Revoked keys and keys not |
| 531 | * providing the requested permission are skipped over. |
| 532 | * |
| 533 | * If successful, the possession indicator is propagated from the keyring ref |
| 534 | * to the returned key reference. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 536 | key_ref_t __keyring_search_one(key_ref_t keyring_ref, |
| 537 | const struct key_type *ktype, |
| 538 | const char *description, |
| 539 | key_perm_t perm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | { |
| 541 | struct keyring_list *klist; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 542 | unsigned long possessed; |
| 543 | struct key *keyring, *key; |
David Howells | efde8b6 | 2012-01-17 20:39:40 +0000 | [diff] [blame] | 544 | int nkeys, loop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 546 | keyring = key_ref_to_ptr(keyring_ref); |
| 547 | possessed = is_key_possessed(keyring_ref); |
| 548 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 549 | rcu_read_lock(); |
| 550 | |
| 551 | klist = rcu_dereference(keyring->payload.subscriptions); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | if (klist) { |
David Howells | efde8b6 | 2012-01-17 20:39:40 +0000 | [diff] [blame] | 553 | nkeys = klist->nkeys; |
| 554 | smp_rmb(); |
| 555 | for (loop = 0; loop < nkeys ; loop++) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 556 | key = rcu_dereference(klist->keys[loop]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | if (key->type == ktype && |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 558 | (!key->type->match || |
| 559 | key->type->match(key, description)) && |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 560 | key_permission(make_key_ref(key, possessed), |
David Howells | db1d1d5 | 2005-12-01 00:51:18 -0800 | [diff] [blame] | 561 | perm) == 0 && |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 562 | !test_bit(KEY_FLAG_REVOKED, &key->flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | ) |
| 564 | goto found; |
| 565 | } |
| 566 | } |
| 567 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 568 | rcu_read_unlock(); |
| 569 | return ERR_PTR(-ENOKEY); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 571 | found: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | atomic_inc(&key->usage); |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 573 | keyring->last_used_at = key->last_used_at = |
| 574 | current_kernel_time().tv_sec; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 575 | rcu_read_unlock(); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 576 | return make_key_ref(key, possessed); |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 577 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 580 | * Find a keyring with the specified name. |
| 581 | * |
| 582 | * All named keyrings in the current user namespace are searched, provided they |
| 583 | * grant Search permission directly to the caller (unless this check is |
| 584 | * skipped). Keyrings whose usage points have reached zero or who have been |
| 585 | * revoked are skipped. |
| 586 | * |
| 587 | * Returns a pointer to the keyring with the keyring's refcount having being |
| 588 | * incremented on success. -ENOKEY is returned if a key could not be found. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | */ |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 590 | struct key *find_keyring_by_name(const char *name, bool skip_perm_check) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | { |
| 592 | struct key *keyring; |
| 593 | int bucket; |
| 594 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | if (!name) |
Toshiyuki Okajima | cea7daa | 2010-04-30 14:32:13 +0100 | [diff] [blame] | 596 | return ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | |
| 598 | bucket = keyring_hash(name); |
| 599 | |
| 600 | read_lock(&keyring_name_lock); |
| 601 | |
| 602 | if (keyring_name_hash[bucket].next) { |
| 603 | /* search this hash bucket for a keyring with a matching name |
| 604 | * that's readable and that hasn't been revoked */ |
| 605 | list_for_each_entry(keyring, |
| 606 | &keyring_name_hash[bucket], |
| 607 | type_data.link |
| 608 | ) { |
Serge E. Hallyn | 2ea190d | 2009-02-26 18:27:55 -0600 | [diff] [blame] | 609 | if (keyring->user->user_ns != current_user_ns()) |
| 610 | continue; |
| 611 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 612 | if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | continue; |
| 614 | |
| 615 | if (strcmp(keyring->description, name) != 0) |
| 616 | continue; |
| 617 | |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 618 | if (!skip_perm_check && |
| 619 | key_permission(make_key_ref(keyring, 0), |
David Howells | 0f6ed7c | 2005-11-07 00:59:30 -0800 | [diff] [blame] | 620 | KEY_SEARCH) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | continue; |
| 622 | |
Toshiyuki Okajima | cea7daa | 2010-04-30 14:32:13 +0100 | [diff] [blame] | 623 | /* we've got a match but we might end up racing with |
| 624 | * key_cleanup() if the keyring is currently 'dead' |
| 625 | * (ie. it has a zero usage count) */ |
| 626 | if (!atomic_inc_not_zero(&keyring->usage)) |
| 627 | continue; |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 628 | keyring->last_used_at = current_kernel_time().tv_sec; |
Toshiyuki Okajima | cea7daa | 2010-04-30 14:32:13 +0100 | [diff] [blame] | 629 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | } |
| 631 | } |
| 632 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | keyring = ERR_PTR(-ENOKEY); |
Toshiyuki Okajima | cea7daa | 2010-04-30 14:32:13 +0100 | [diff] [blame] | 634 | out: |
| 635 | read_unlock(&keyring_name_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | return keyring; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 637 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 640 | * See if a cycle will will be created by inserting acyclic tree B in acyclic |
| 641 | * tree A at the topmost level (ie: as a direct child of A). |
| 642 | * |
| 643 | * Since we are adding B to A at the top level, checking for cycles should just |
| 644 | * be a matter of seeing if node A is somewhere in tree B. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | */ |
| 646 | static int keyring_detect_cycle(struct key *A, struct key *B) |
| 647 | { |
| 648 | struct { |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 649 | struct keyring_list *keylist; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | int kix; |
| 651 | } stack[KEYRING_SEARCH_MAX_DEPTH]; |
| 652 | |
| 653 | struct keyring_list *keylist; |
| 654 | struct key *subtree, *key; |
David Howells | efde8b6 | 2012-01-17 20:39:40 +0000 | [diff] [blame] | 655 | int sp, nkeys, kix, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 657 | rcu_read_lock(); |
| 658 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | ret = -EDEADLK; |
| 660 | if (A == B) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 661 | goto cycle_detected; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | |
| 663 | subtree = B; |
| 664 | sp = 0; |
| 665 | |
| 666 | /* start processing a new keyring */ |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 667 | descend: |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 668 | if (test_bit(KEY_FLAG_REVOKED, &subtree->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | goto not_this_keyring; |
| 670 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 671 | keylist = rcu_dereference(subtree->payload.subscriptions); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | if (!keylist) |
| 673 | goto not_this_keyring; |
| 674 | kix = 0; |
| 675 | |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 676 | ascend: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | /* iterate through the remaining keys in this keyring */ |
David Howells | efde8b6 | 2012-01-17 20:39:40 +0000 | [diff] [blame] | 678 | nkeys = keylist->nkeys; |
| 679 | smp_rmb(); |
| 680 | for (; kix < nkeys; kix++) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 681 | key = rcu_dereference(keylist->keys[kix]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | |
| 683 | if (key == A) |
| 684 | goto cycle_detected; |
| 685 | |
| 686 | /* recursively check nested keyrings */ |
| 687 | if (key->type == &key_type_keyring) { |
| 688 | if (sp >= KEYRING_SEARCH_MAX_DEPTH) |
| 689 | goto too_deep; |
| 690 | |
| 691 | /* stack the current position */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 692 | stack[sp].keylist = keylist; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | stack[sp].kix = kix; |
| 694 | sp++; |
| 695 | |
| 696 | /* begin again with the new keyring */ |
| 697 | subtree = key; |
| 698 | goto descend; |
| 699 | } |
| 700 | } |
| 701 | |
| 702 | /* the keyring we're looking at was disqualified or didn't contain a |
| 703 | * matching key */ |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 704 | not_this_keyring: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | if (sp > 0) { |
| 706 | /* resume the checking of a keyring higher up in the tree */ |
| 707 | sp--; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 708 | keylist = stack[sp].keylist; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | kix = stack[sp].kix + 1; |
| 710 | goto ascend; |
| 711 | } |
| 712 | |
| 713 | ret = 0; /* no cycles detected */ |
| 714 | |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 715 | error: |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 716 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | return ret; |
| 718 | |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 719 | too_deep: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | ret = -ELOOP; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 721 | goto error; |
| 722 | |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 723 | cycle_detected: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | ret = -EDEADLK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | goto error; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 726 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 728 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 729 | * Dispose of a keyring list after the RCU grace period, freeing the unlinked |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 730 | * key |
| 731 | */ |
| 732 | static void keyring_unlink_rcu_disposal(struct rcu_head *rcu) |
| 733 | { |
| 734 | struct keyring_list *klist = |
| 735 | container_of(rcu, struct keyring_list, rcu); |
| 736 | |
Alexey Dobriyan | 4be929b | 2010-05-24 14:33:03 -0700 | [diff] [blame] | 737 | if (klist->delkey != USHRT_MAX) |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 738 | key_put(rcu_access_pointer(klist->keys[klist->delkey])); |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 739 | kfree(klist); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 740 | } |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 741 | |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 742 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 743 | * Preallocate memory so that a key can be linked into to a keyring. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | */ |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 745 | int __key_link_begin(struct key *keyring, const struct key_type *type, |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 746 | const char *description, unsigned long *_prealloc) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 747 | __acquires(&keyring->sem) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | { |
| 749 | struct keyring_list *klist, *nklist; |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 750 | unsigned long prealloc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | unsigned max; |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 752 | time_t lowest_lru; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | size_t size; |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 754 | int loop, lru, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 756 | kenter("%d,%s,%s,", key_serial(keyring), type->name, description); |
| 757 | |
| 758 | if (keyring->type != &key_type_keyring) |
| 759 | return -ENOTDIR; |
| 760 | |
| 761 | down_write(&keyring->sem); |
| 762 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | ret = -EKEYREVOKED; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 764 | if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 765 | goto error_krsem; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 767 | /* serialise link/link calls to prevent parallel calls causing a cycle |
| 768 | * when linking two keyring in opposite orders */ |
| 769 | if (type == &key_type_keyring) |
David Howells | 553d603 | 2010-04-30 14:32:28 +0100 | [diff] [blame] | 770 | down_write(&keyring_serialise_link_sem); |
| 771 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 772 | klist = rcu_dereference_locked_keyring(keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 774 | /* see if there's a matching key we can displace */ |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 775 | lru = -1; |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 776 | if (klist && klist->nkeys > 0) { |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 777 | lowest_lru = TIME_T_MAX; |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 778 | for (loop = klist->nkeys - 1; loop >= 0; loop--) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 779 | struct key *key = rcu_deref_link_locked(klist, loop, |
| 780 | keyring); |
| 781 | if (key->type == type && |
| 782 | strcmp(key->description, description) == 0) { |
| 783 | /* Found a match - we'll replace the link with |
| 784 | * one to the new key. We record the slot |
| 785 | * position. |
| 786 | */ |
| 787 | klist->delkey = loop; |
| 788 | prealloc = 0; |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 789 | goto done; |
| 790 | } |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 791 | if (key->last_used_at < lowest_lru) { |
| 792 | lowest_lru = key->last_used_at; |
| 793 | lru = loop; |
| 794 | } |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 795 | } |
| 796 | } |
| 797 | |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 798 | /* If the keyring is full then do an LRU discard */ |
| 799 | if (klist && |
| 800 | klist->nkeys == klist->maxkeys && |
| 801 | klist->maxkeys >= MAX_KEYRING_LINKS) { |
| 802 | kdebug("LRU discard %d\n", lru); |
| 803 | klist->delkey = lru; |
| 804 | prealloc = 0; |
| 805 | goto done; |
| 806 | } |
| 807 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | /* check that we aren't going to overrun the user's quota */ |
| 809 | ret = key_payload_reserve(keyring, |
| 810 | keyring->datalen + KEYQUOTA_LINK_BYTES); |
| 811 | if (ret < 0) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 812 | goto error_sem; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | if (klist && klist->nkeys < klist->maxkeys) { |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 815 | /* there's sufficient slack space to append directly */ |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 816 | klist->delkey = klist->nkeys; |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 817 | prealloc = KEY_LINK_FIXQUOTA; |
Chihau Chau | 512ea3b | 2010-03-08 20:11:34 -0300 | [diff] [blame] | 818 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | /* grow the key list */ |
| 820 | max = 4; |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 821 | if (klist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | max += klist->maxkeys; |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 823 | if (max > MAX_KEYRING_LINKS) |
| 824 | max = MAX_KEYRING_LINKS; |
| 825 | BUG_ON(max <= klist->maxkeys); |
| 826 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | |
David Howells | a4014d8 | 2005-07-07 17:57:03 -0700 | [diff] [blame] | 828 | size = sizeof(*klist) + sizeof(struct key *) * max; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | |
| 830 | ret = -ENOMEM; |
| 831 | nklist = kmalloc(size, GFP_KERNEL); |
| 832 | if (!nklist) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 833 | goto error_quota; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 835 | nklist->maxkeys = max; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | if (klist) { |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 837 | memcpy(nklist->keys, klist->keys, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | sizeof(struct key *) * klist->nkeys); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 839 | nklist->delkey = klist->nkeys; |
| 840 | nklist->nkeys = klist->nkeys + 1; |
Alexey Dobriyan | 4be929b | 2010-05-24 14:33:03 -0700 | [diff] [blame] | 841 | klist->delkey = USHRT_MAX; |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 842 | } else { |
| 843 | nklist->nkeys = 1; |
| 844 | nklist->delkey = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | } |
| 846 | |
| 847 | /* add the key into the new space */ |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 848 | RCU_INIT_POINTER(nklist->keys[nklist->delkey], NULL); |
| 849 | prealloc = (unsigned long)nklist | KEY_LINK_FIXQUOTA; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | } |
| 851 | |
David Howells | cab8eb5 | 2006-01-08 01:02:45 -0800 | [diff] [blame] | 852 | done: |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 853 | *_prealloc = prealloc; |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 854 | kleave(" = 0"); |
| 855 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 857 | error_quota: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | /* undo the quota changes */ |
| 859 | key_payload_reserve(keyring, |
| 860 | keyring->datalen - KEYQUOTA_LINK_BYTES); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 861 | error_sem: |
| 862 | if (type == &key_type_keyring) |
| 863 | up_write(&keyring_serialise_link_sem); |
| 864 | error_krsem: |
| 865 | up_write(&keyring->sem); |
| 866 | kleave(" = %d", ret); |
| 867 | return ret; |
| 868 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 870 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 871 | * Check already instantiated keys aren't going to be a problem. |
| 872 | * |
| 873 | * The caller must have called __key_link_begin(). Don't need to call this for |
| 874 | * keys that were created since __key_link_begin() was called. |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 875 | */ |
| 876 | int __key_link_check_live_key(struct key *keyring, struct key *key) |
| 877 | { |
| 878 | if (key->type == &key_type_keyring) |
| 879 | /* check that we aren't going to create a cycle by linking one |
| 880 | * keyring to another */ |
| 881 | return keyring_detect_cycle(keyring, key); |
| 882 | return 0; |
| 883 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 885 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 886 | * Link a key into to a keyring. |
| 887 | * |
| 888 | * Must be called with __key_link_begin() having being called. Discards any |
| 889 | * already extant link to matching key if there is one, so that each keyring |
| 890 | * holds at most one link to any given key of a particular type+description |
| 891 | * combination. |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 892 | */ |
| 893 | void __key_link(struct key *keyring, struct key *key, |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 894 | unsigned long *_prealloc) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 895 | { |
| 896 | struct keyring_list *klist, *nklist; |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 897 | struct key *discard; |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 898 | |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 899 | nklist = (struct keyring_list *)(*_prealloc & ~KEY_LINK_FIXQUOTA); |
| 900 | *_prealloc = 0; |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 901 | |
| 902 | kenter("%d,%d,%p", keyring->serial, key->serial, nklist); |
| 903 | |
David Howells | 6d528b0 | 2011-08-22 14:08:51 +0100 | [diff] [blame] | 904 | klist = rcu_dereference_locked_keyring(keyring); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 905 | |
| 906 | atomic_inc(&key->usage); |
David Howells | 31d5a79 | 2012-05-11 10:56:56 +0100 | [diff] [blame^] | 907 | keyring->last_used_at = key->last_used_at = |
| 908 | current_kernel_time().tv_sec; |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 909 | |
| 910 | /* there's a matching key we can displace or an empty slot in a newly |
| 911 | * allocated list we can fill */ |
| 912 | if (nklist) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 913 | kdebug("reissue %hu/%hu/%hu", |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 914 | nklist->delkey, nklist->nkeys, nklist->maxkeys); |
| 915 | |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 916 | RCU_INIT_POINTER(nklist->keys[nklist->delkey], key); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 917 | |
| 918 | rcu_assign_pointer(keyring->payload.subscriptions, nklist); |
| 919 | |
| 920 | /* dispose of the old keyring list and, if there was one, the |
| 921 | * displaced key */ |
| 922 | if (klist) { |
| 923 | kdebug("dispose %hu/%hu/%hu", |
| 924 | klist->delkey, klist->nkeys, klist->maxkeys); |
| 925 | call_rcu(&klist->rcu, keyring_unlink_rcu_disposal); |
| 926 | } |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 927 | } else if (klist->delkey < klist->nkeys) { |
| 928 | kdebug("replace %hu/%hu/%hu", |
| 929 | klist->delkey, klist->nkeys, klist->maxkeys); |
| 930 | |
| 931 | discard = rcu_dereference_protected( |
| 932 | klist->keys[klist->delkey], |
| 933 | rwsem_is_locked(&keyring->sem)); |
| 934 | rcu_assign_pointer(klist->keys[klist->delkey], key); |
| 935 | /* The garbage collector will take care of RCU |
| 936 | * synchronisation */ |
| 937 | key_put(discard); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 938 | } else { |
| 939 | /* there's sufficient slack space to append directly */ |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 940 | kdebug("append %hu/%hu/%hu", |
| 941 | klist->delkey, klist->nkeys, klist->maxkeys); |
| 942 | |
| 943 | RCU_INIT_POINTER(klist->keys[klist->delkey], key); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 944 | smp_wmb(); |
| 945 | klist->nkeys++; |
| 946 | } |
| 947 | } |
| 948 | |
| 949 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 950 | * Finish linking a key into to a keyring. |
| 951 | * |
| 952 | * Must be called with __key_link_begin() having being called. |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 953 | */ |
| 954 | void __key_link_end(struct key *keyring, struct key_type *type, |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 955 | unsigned long prealloc) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 956 | __releases(&keyring->sem) |
| 957 | { |
| 958 | BUG_ON(type == NULL); |
| 959 | BUG_ON(type->name == NULL); |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 960 | kenter("%d,%s,%lx", keyring->serial, type->name, prealloc); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 961 | |
| 962 | if (type == &key_type_keyring) |
| 963 | up_write(&keyring_serialise_link_sem); |
| 964 | |
| 965 | if (prealloc) { |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 966 | if (prealloc & KEY_LINK_FIXQUOTA) |
| 967 | key_payload_reserve(keyring, |
| 968 | keyring->datalen - |
| 969 | KEYQUOTA_LINK_BYTES); |
| 970 | kfree((struct keyring_list *)(prealloc & ~KEY_LINK_FIXQUOTA)); |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 971 | } |
| 972 | up_write(&keyring->sem); |
| 973 | } |
| 974 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 975 | /** |
| 976 | * key_link - Link a key to a keyring |
| 977 | * @keyring: The keyring to make the link in. |
| 978 | * @key: The key to link to. |
| 979 | * |
| 980 | * Make a link in a keyring to a key, such that the keyring holds a reference |
| 981 | * on that key and the key can potentially be found by searching that keyring. |
| 982 | * |
| 983 | * This function will write-lock the keyring's semaphore and will consume some |
| 984 | * of the user's key data quota to hold the link. |
| 985 | * |
| 986 | * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring, |
| 987 | * -EKEYREVOKED if the keyring has been revoked, -ENFILE if the keyring is |
| 988 | * full, -EDQUOT if there is insufficient key data quota remaining to add |
| 989 | * another link or -ENOMEM if there's insufficient memory. |
| 990 | * |
| 991 | * It is assumed that the caller has checked that it is permitted for a link to |
| 992 | * be made (the keyring should have Write permission and the key Link |
| 993 | * permission). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | */ |
| 995 | int key_link(struct key *keyring, struct key *key) |
| 996 | { |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame] | 997 | unsigned long prealloc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | int ret; |
| 999 | |
| 1000 | key_check(keyring); |
| 1001 | key_check(key); |
| 1002 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 1003 | ret = __key_link_begin(keyring, key->type, key->description, &prealloc); |
| 1004 | if (ret == 0) { |
| 1005 | ret = __key_link_check_live_key(keyring, key); |
| 1006 | if (ret == 0) |
| 1007 | __key_link(keyring, key, &prealloc); |
| 1008 | __key_link_end(keyring, key->type, prealloc); |
| 1009 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | |
| 1011 | return ret; |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 1012 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1013 | EXPORT_SYMBOL(key_link); |
| 1014 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1015 | /** |
| 1016 | * key_unlink - Unlink the first link to a key from a keyring. |
| 1017 | * @keyring: The keyring to remove the link from. |
| 1018 | * @key: The key the link is to. |
| 1019 | * |
| 1020 | * Remove a link from a keyring to a key. |
| 1021 | * |
| 1022 | * This function will write-lock the keyring's semaphore. |
| 1023 | * |
| 1024 | * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring, -ENOENT if |
| 1025 | * the key isn't linked to by the keyring or -ENOMEM if there's insufficient |
| 1026 | * memory. |
| 1027 | * |
| 1028 | * It is assumed that the caller has checked that it is permitted for a link to |
| 1029 | * be removed (the keyring should have Write permission; no permissions are |
| 1030 | * required on the key). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1031 | */ |
| 1032 | int key_unlink(struct key *keyring, struct key *key) |
| 1033 | { |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1034 | struct keyring_list *klist, *nklist; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1035 | int loop, ret; |
| 1036 | |
| 1037 | key_check(keyring); |
| 1038 | key_check(key); |
| 1039 | |
| 1040 | ret = -ENOTDIR; |
| 1041 | if (keyring->type != &key_type_keyring) |
| 1042 | goto error; |
| 1043 | |
| 1044 | down_write(&keyring->sem); |
| 1045 | |
David Howells | f0641cb | 2010-04-30 14:32:18 +0100 | [diff] [blame] | 1046 | klist = rcu_dereference_locked_keyring(keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1047 | if (klist) { |
| 1048 | /* search the keyring for the key */ |
| 1049 | for (loop = 0; loop < klist->nkeys; loop++) |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 1050 | if (rcu_access_pointer(klist->keys[loop]) == key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1051 | goto key_is_present; |
| 1052 | } |
| 1053 | |
| 1054 | up_write(&keyring->sem); |
| 1055 | ret = -ENOENT; |
| 1056 | goto error; |
| 1057 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1058 | key_is_present: |
| 1059 | /* we need to copy the key list for RCU purposes */ |
David Howells | a4014d8 | 2005-07-07 17:57:03 -0700 | [diff] [blame] | 1060 | nklist = kmalloc(sizeof(*klist) + |
| 1061 | sizeof(struct key *) * klist->maxkeys, |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1062 | GFP_KERNEL); |
| 1063 | if (!nklist) |
| 1064 | goto nomem; |
| 1065 | nklist->maxkeys = klist->maxkeys; |
| 1066 | nklist->nkeys = klist->nkeys - 1; |
| 1067 | |
| 1068 | if (loop > 0) |
| 1069 | memcpy(&nklist->keys[0], |
| 1070 | &klist->keys[0], |
David Howells | a4014d8 | 2005-07-07 17:57:03 -0700 | [diff] [blame] | 1071 | loop * sizeof(struct key *)); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1072 | |
| 1073 | if (loop < nklist->nkeys) |
| 1074 | memcpy(&nklist->keys[loop], |
| 1075 | &klist->keys[loop + 1], |
David Howells | a4014d8 | 2005-07-07 17:57:03 -0700 | [diff] [blame] | 1076 | (nklist->nkeys - loop) * sizeof(struct key *)); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1077 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | /* adjust the user's quota */ |
| 1079 | key_payload_reserve(keyring, |
| 1080 | keyring->datalen - KEYQUOTA_LINK_BYTES); |
| 1081 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1082 | rcu_assign_pointer(keyring->payload.subscriptions, nklist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1083 | |
| 1084 | up_write(&keyring->sem); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1085 | |
| 1086 | /* schedule for later cleanup */ |
| 1087 | klist->delkey = loop; |
| 1088 | call_rcu(&klist->rcu, keyring_unlink_rcu_disposal); |
| 1089 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | ret = 0; |
| 1091 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1092 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | return ret; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1094 | nomem: |
| 1095 | ret = -ENOMEM; |
| 1096 | up_write(&keyring->sem); |
| 1097 | goto error; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 1098 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1099 | EXPORT_SYMBOL(key_unlink); |
| 1100 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1101 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1102 | * Dispose of a keyring list after the RCU grace period, releasing the keys it |
| 1103 | * links to. |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1104 | */ |
| 1105 | static void keyring_clear_rcu_disposal(struct rcu_head *rcu) |
| 1106 | { |
| 1107 | struct keyring_list *klist; |
| 1108 | int loop; |
| 1109 | |
| 1110 | klist = container_of(rcu, struct keyring_list, rcu); |
| 1111 | |
| 1112 | for (loop = klist->nkeys - 1; loop >= 0; loop--) |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 1113 | key_put(rcu_access_pointer(klist->keys[loop])); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1114 | |
| 1115 | kfree(klist); |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 1116 | } |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1117 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1118 | /** |
| 1119 | * keyring_clear - Clear a keyring |
| 1120 | * @keyring: The keyring to clear. |
| 1121 | * |
| 1122 | * Clear the contents of the specified keyring. |
| 1123 | * |
| 1124 | * Returns 0 if successful or -ENOTDIR if the keyring isn't a keyring. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1125 | */ |
| 1126 | int keyring_clear(struct key *keyring) |
| 1127 | { |
| 1128 | struct keyring_list *klist; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1129 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | |
| 1131 | ret = -ENOTDIR; |
| 1132 | if (keyring->type == &key_type_keyring) { |
| 1133 | /* detach the pointer block with the locks held */ |
| 1134 | down_write(&keyring->sem); |
| 1135 | |
David Howells | f0641cb | 2010-04-30 14:32:18 +0100 | [diff] [blame] | 1136 | klist = rcu_dereference_locked_keyring(keyring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | if (klist) { |
| 1138 | /* adjust the quota */ |
| 1139 | key_payload_reserve(keyring, |
| 1140 | sizeof(struct keyring_list)); |
| 1141 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1142 | rcu_assign_pointer(keyring->payload.subscriptions, |
| 1143 | NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | } |
| 1145 | |
| 1146 | up_write(&keyring->sem); |
| 1147 | |
| 1148 | /* free the keys after the locks have been dropped */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1149 | if (klist) |
| 1150 | call_rcu(&klist->rcu, keyring_clear_rcu_disposal); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1151 | |
| 1152 | ret = 0; |
| 1153 | } |
| 1154 | |
| 1155 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 1156 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | EXPORT_SYMBOL(keyring_clear); |
David Howells | 31204ed | 2006-06-26 00:24:51 -0700 | [diff] [blame] | 1158 | |
David Howells | 31204ed | 2006-06-26 00:24:51 -0700 | [diff] [blame] | 1159 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1160 | * Dispose of the links from a revoked keyring. |
| 1161 | * |
| 1162 | * This is called with the key sem write-locked. |
David Howells | 31204ed | 2006-06-26 00:24:51 -0700 | [diff] [blame] | 1163 | */ |
| 1164 | static void keyring_revoke(struct key *keyring) |
| 1165 | { |
David Howells | f0641cb | 2010-04-30 14:32:18 +0100 | [diff] [blame] | 1166 | struct keyring_list *klist; |
| 1167 | |
| 1168 | klist = rcu_dereference_locked_keyring(keyring); |
David Howells | 31204ed | 2006-06-26 00:24:51 -0700 | [diff] [blame] | 1169 | |
| 1170 | /* adjust the quota */ |
| 1171 | key_payload_reserve(keyring, 0); |
| 1172 | |
| 1173 | if (klist) { |
| 1174 | rcu_assign_pointer(keyring->payload.subscriptions, NULL); |
| 1175 | call_rcu(&klist->rcu, keyring_clear_rcu_disposal); |
| 1176 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 1177 | } |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1178 | |
| 1179 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1180 | * Determine whether a key is dead. |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1181 | */ |
| 1182 | static bool key_is_dead(struct key *key, time_t limit) |
| 1183 | { |
| 1184 | return test_bit(KEY_FLAG_DEAD, &key->flags) || |
| 1185 | (key->expiry > 0 && key->expiry <= limit); |
| 1186 | } |
| 1187 | |
| 1188 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1189 | * Collect garbage from the contents of a keyring, replacing the old list with |
| 1190 | * a new one with the pointers all shuffled down. |
| 1191 | * |
| 1192 | * Dead keys are classed as oned that are flagged as being dead or are revoked, |
| 1193 | * expired or negative keys that were revoked or expired before the specified |
| 1194 | * limit. |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1195 | */ |
| 1196 | void keyring_gc(struct key *keyring, time_t limit) |
| 1197 | { |
| 1198 | struct keyring_list *klist, *new; |
| 1199 | struct key *key; |
| 1200 | int loop, keep, max; |
| 1201 | |
David Howells | c08ef80 | 2009-09-14 17:26:13 +0100 | [diff] [blame] | 1202 | kenter("{%x,%s}", key_serial(keyring), keyring->description); |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1203 | |
| 1204 | down_write(&keyring->sem); |
| 1205 | |
David Howells | f0641cb | 2010-04-30 14:32:18 +0100 | [diff] [blame] | 1206 | klist = rcu_dereference_locked_keyring(keyring); |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1207 | if (!klist) |
David Howells | c08ef80 | 2009-09-14 17:26:13 +0100 | [diff] [blame] | 1208 | goto no_klist; |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1209 | |
| 1210 | /* work out how many subscriptions we're keeping */ |
| 1211 | keep = 0; |
| 1212 | for (loop = klist->nkeys - 1; loop >= 0; loop--) |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 1213 | if (!key_is_dead(rcu_deref_link_locked(klist, loop, keyring), |
| 1214 | limit)) |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1215 | keep++; |
| 1216 | |
| 1217 | if (keep == klist->nkeys) |
| 1218 | goto just_return; |
| 1219 | |
| 1220 | /* allocate a new keyring payload */ |
| 1221 | max = roundup(keep, 4); |
| 1222 | new = kmalloc(sizeof(struct keyring_list) + max * sizeof(struct key *), |
| 1223 | GFP_KERNEL); |
| 1224 | if (!new) |
David Howells | c08ef80 | 2009-09-14 17:26:13 +0100 | [diff] [blame] | 1225 | goto nomem; |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1226 | new->maxkeys = max; |
| 1227 | new->nkeys = 0; |
| 1228 | new->delkey = 0; |
| 1229 | |
| 1230 | /* install the live keys |
| 1231 | * - must take care as expired keys may be updated back to life |
| 1232 | */ |
| 1233 | keep = 0; |
| 1234 | for (loop = klist->nkeys - 1; loop >= 0; loop--) { |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 1235 | key = rcu_deref_link_locked(klist, loop, keyring); |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1236 | if (!key_is_dead(key, limit)) { |
| 1237 | if (keep >= max) |
| 1238 | goto discard_new; |
David Howells | 233e473 | 2012-05-11 10:56:56 +0100 | [diff] [blame] | 1239 | RCU_INIT_POINTER(new->keys[keep++], key_get(key)); |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1240 | } |
| 1241 | } |
| 1242 | new->nkeys = keep; |
| 1243 | |
| 1244 | /* adjust the quota */ |
| 1245 | key_payload_reserve(keyring, |
| 1246 | sizeof(struct keyring_list) + |
| 1247 | KEYQUOTA_LINK_BYTES * keep); |
| 1248 | |
| 1249 | if (keep == 0) { |
| 1250 | rcu_assign_pointer(keyring->payload.subscriptions, NULL); |
| 1251 | kfree(new); |
| 1252 | } else { |
| 1253 | rcu_assign_pointer(keyring->payload.subscriptions, new); |
| 1254 | } |
| 1255 | |
| 1256 | up_write(&keyring->sem); |
| 1257 | |
| 1258 | call_rcu(&klist->rcu, keyring_clear_rcu_disposal); |
| 1259 | kleave(" [yes]"); |
| 1260 | return; |
| 1261 | |
| 1262 | discard_new: |
| 1263 | new->nkeys = keep; |
| 1264 | keyring_clear_rcu_disposal(&new->rcu); |
David Howells | c08ef80 | 2009-09-14 17:26:13 +0100 | [diff] [blame] | 1265 | up_write(&keyring->sem); |
| 1266 | kleave(" [discard]"); |
| 1267 | return; |
| 1268 | |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1269 | just_return: |
| 1270 | up_write(&keyring->sem); |
David Howells | c08ef80 | 2009-09-14 17:26:13 +0100 | [diff] [blame] | 1271 | kleave(" [no dead]"); |
| 1272 | return; |
| 1273 | |
| 1274 | no_klist: |
| 1275 | up_write(&keyring->sem); |
| 1276 | kleave(" [no_klist]"); |
| 1277 | return; |
| 1278 | |
| 1279 | nomem: |
| 1280 | up_write(&keyring->sem); |
| 1281 | kleave(" [oom]"); |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1282 | } |