David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 1 | /* Basic authentication token and access key management |
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) 2004-2008 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> |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 14 | #include <linux/poison.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/sched.h> |
| 16 | #include <linux/slab.h> |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 17 | #include <linux/security.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/workqueue.h> |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 19 | #include <linux/random.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/err.h> |
Serge E. Hallyn | 1d1e975 | 2009-02-26 18:27:38 -0600 | [diff] [blame] | 21 | #include <linux/user_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include "internal.h" |
| 23 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 24 | static struct kmem_cache *key_jar; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | struct rb_root key_serial_tree; /* tree of keys indexed by serial */ |
| 26 | DEFINE_SPINLOCK(key_serial_lock); |
| 27 | |
| 28 | struct rb_root key_user_tree; /* tree of quota records indexed by UID */ |
| 29 | DEFINE_SPINLOCK(key_user_lock); |
| 30 | |
David Howells | 0b77f5b | 2008-04-29 01:01:32 -0700 | [diff] [blame] | 31 | unsigned int key_quota_root_maxkeys = 200; /* root's key count quota */ |
| 32 | unsigned int key_quota_root_maxbytes = 20000; /* root's key space quota */ |
| 33 | unsigned int key_quota_maxkeys = 200; /* general key count quota */ |
| 34 | unsigned int key_quota_maxbytes = 20000; /* general key space quota */ |
| 35 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | static LIST_HEAD(key_types_list); |
| 37 | static DECLARE_RWSEM(key_types_sem); |
| 38 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 39 | static void key_cleanup(struct work_struct *work); |
| 40 | static DECLARE_WORK(key_cleanup_task, key_cleanup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 42 | /* We serialise key instantiation and link */ |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 43 | DEFINE_MUTEX(key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 45 | /* Any key who's type gets unegistered will be re-typed to this */ |
Adrian Bunk | 1ae8f40 | 2006-01-06 00:11:25 -0800 | [diff] [blame] | 46 | static struct key_type key_type_dead = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | .name = "dead", |
| 48 | }; |
| 49 | |
| 50 | #ifdef KEY_DEBUGGING |
| 51 | void __key_check(const struct key *key) |
| 52 | { |
| 53 | printk("__key_check: key %p {%08x} should be {%08x}\n", |
| 54 | key, key->magic, KEY_DEBUG_MAGIC); |
| 55 | BUG(); |
| 56 | } |
| 57 | #endif |
| 58 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 60 | * Get the key quota record for a user, allocating a new record if one doesn't |
| 61 | * already exist. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | */ |
Serge E. Hallyn | 1d1e975 | 2009-02-26 18:27:38 -0600 | [diff] [blame] | 63 | struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | { |
| 65 | struct key_user *candidate = NULL, *user; |
| 66 | struct rb_node *parent = NULL; |
| 67 | struct rb_node **p; |
| 68 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 69 | try_again: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | p = &key_user_tree.rb_node; |
| 71 | spin_lock(&key_user_lock); |
| 72 | |
| 73 | /* search the tree for a user record with a matching UID */ |
| 74 | while (*p) { |
| 75 | parent = *p; |
| 76 | user = rb_entry(parent, struct key_user, node); |
| 77 | |
| 78 | if (uid < user->uid) |
| 79 | p = &(*p)->rb_left; |
| 80 | else if (uid > user->uid) |
| 81 | p = &(*p)->rb_right; |
Serge E. Hallyn | 1d1e975 | 2009-02-26 18:27:38 -0600 | [diff] [blame] | 82 | else if (user_ns < user->user_ns) |
| 83 | p = &(*p)->rb_left; |
| 84 | else if (user_ns > user->user_ns) |
| 85 | p = &(*p)->rb_right; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | else |
| 87 | goto found; |
| 88 | } |
| 89 | |
| 90 | /* if we get here, we failed to find a match in the tree */ |
| 91 | if (!candidate) { |
| 92 | /* allocate a candidate user record if we don't already have |
| 93 | * one */ |
| 94 | spin_unlock(&key_user_lock); |
| 95 | |
| 96 | user = NULL; |
| 97 | candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); |
| 98 | if (unlikely(!candidate)) |
| 99 | goto out; |
| 100 | |
| 101 | /* the allocation may have scheduled, so we need to repeat the |
| 102 | * search lest someone else added the record whilst we were |
| 103 | * asleep */ |
| 104 | goto try_again; |
| 105 | } |
| 106 | |
| 107 | /* if we get here, then the user record still hadn't appeared on the |
| 108 | * second pass - so we use the candidate record */ |
| 109 | atomic_set(&candidate->usage, 1); |
| 110 | atomic_set(&candidate->nkeys, 0); |
| 111 | atomic_set(&candidate->nikeys, 0); |
| 112 | candidate->uid = uid; |
Serge E. Hallyn | 1d1e975 | 2009-02-26 18:27:38 -0600 | [diff] [blame] | 113 | candidate->user_ns = get_user_ns(user_ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | candidate->qnkeys = 0; |
| 115 | candidate->qnbytes = 0; |
| 116 | spin_lock_init(&candidate->lock); |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 117 | mutex_init(&candidate->cons_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
| 119 | rb_link_node(&candidate->node, parent, p); |
| 120 | rb_insert_color(&candidate->node, &key_user_tree); |
| 121 | spin_unlock(&key_user_lock); |
| 122 | user = candidate; |
| 123 | goto out; |
| 124 | |
| 125 | /* okay - we found a user record for this UID */ |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 126 | found: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | atomic_inc(&user->usage); |
| 128 | spin_unlock(&key_user_lock); |
Jesper Juhl | a7f988b | 2005-11-07 01:01:35 -0800 | [diff] [blame] | 129 | kfree(candidate); |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 130 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | return user; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 132 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 135 | * Dispose of a user structure |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | */ |
| 137 | void key_user_put(struct key_user *user) |
| 138 | { |
| 139 | if (atomic_dec_and_lock(&user->usage, &key_user_lock)) { |
| 140 | rb_erase(&user->node, &key_user_tree); |
| 141 | spin_unlock(&key_user_lock); |
Serge E. Hallyn | 1d1e975 | 2009-02-26 18:27:38 -0600 | [diff] [blame] | 142 | put_user_ns(user->user_ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
| 144 | kfree(user); |
| 145 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 146 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 149 | * Allocate a serial number for a key. These are assigned randomly to avoid |
| 150 | * security issues through covert channel problems. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | */ |
| 152 | static inline void key_alloc_serial(struct key *key) |
| 153 | { |
| 154 | struct rb_node *parent, **p; |
| 155 | struct key *xkey; |
| 156 | |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 157 | /* propose a random serial number and look for a hole for it in the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | * serial number tree */ |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 159 | do { |
| 160 | get_random_bytes(&key->serial, sizeof(key->serial)); |
| 161 | |
| 162 | key->serial >>= 1; /* negative numbers are not permitted */ |
| 163 | } while (key->serial < 3); |
| 164 | |
| 165 | spin_lock(&key_serial_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 167 | attempt_insertion: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | parent = NULL; |
| 169 | p = &key_serial_tree.rb_node; |
| 170 | |
| 171 | while (*p) { |
| 172 | parent = *p; |
| 173 | xkey = rb_entry(parent, struct key, serial_node); |
| 174 | |
| 175 | if (key->serial < xkey->serial) |
| 176 | p = &(*p)->rb_left; |
| 177 | else if (key->serial > xkey->serial) |
| 178 | p = &(*p)->rb_right; |
| 179 | else |
| 180 | goto serial_exists; |
| 181 | } |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 182 | |
| 183 | /* we've found a suitable hole - arrange for this key to occupy it */ |
| 184 | rb_link_node(&key->serial_node, parent, p); |
| 185 | rb_insert_color(&key->serial_node, &key_serial_tree); |
| 186 | |
| 187 | spin_unlock(&key_serial_lock); |
| 188 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | |
| 190 | /* we found a key with the proposed serial number - walk the tree from |
| 191 | * that point looking for the next unused serial number */ |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 192 | serial_exists: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | for (;;) { |
Michael LeMay | e51f6d3 | 2006-06-26 00:24:54 -0700 | [diff] [blame] | 194 | key->serial++; |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 195 | if (key->serial < 3) { |
| 196 | key->serial = 3; |
| 197 | goto attempt_insertion; |
| 198 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
| 200 | parent = rb_next(parent); |
| 201 | if (!parent) |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 202 | goto attempt_insertion; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | |
| 204 | xkey = rb_entry(parent, struct key, serial_node); |
| 205 | if (key->serial < xkey->serial) |
David Howells | 9ad0830 | 2007-02-06 13:45:51 +0000 | [diff] [blame] | 206 | goto attempt_insertion; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 208 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 210 | /** |
| 211 | * key_alloc - Allocate a key of the specified type. |
| 212 | * @type: The type of key to allocate. |
| 213 | * @desc: The key description to allow the key to be searched out. |
| 214 | * @uid: The owner of the new key. |
| 215 | * @gid: The group ID for the new key's group permissions. |
| 216 | * @cred: The credentials specifying UID namespace. |
| 217 | * @perm: The permissions mask of the new key. |
| 218 | * @flags: Flags specifying quota properties. |
| 219 | * |
| 220 | * Allocate a key of the specified type with the attributes given. The key is |
| 221 | * returned in an uninstantiated state and the caller needs to instantiate the |
| 222 | * key before returning. |
| 223 | * |
| 224 | * The user's key count quota is updated to reflect the creation of the key and |
| 225 | * the user's key data quota has the default for the key type reserved. The |
| 226 | * instantiation function should amend this as necessary. If insufficient |
| 227 | * quota is available, -EDQUOT will be returned. |
| 228 | * |
| 229 | * The LSM security modules can prevent a key being created, in which case |
| 230 | * -EACCES will be returned. |
| 231 | * |
| 232 | * Returns a pointer to the new key if successful and an error code otherwise. |
| 233 | * |
| 234 | * Note that the caller needs to ensure the key type isn't uninstantiated. |
| 235 | * Internally this can be done by locking key_types_sem. Externally, this can |
| 236 | * be done by either never unregistering the key type, or making sure |
| 237 | * key_alloc() calls don't race with module unloading. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | */ |
| 239 | struct key *key_alloc(struct key_type *type, const char *desc, |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 240 | uid_t uid, gid_t gid, const struct cred *cred, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 241 | key_perm_t perm, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | { |
| 243 | struct key_user *user = NULL; |
| 244 | struct key *key; |
| 245 | size_t desclen, quotalen; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 246 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | |
| 248 | key = ERR_PTR(-EINVAL); |
| 249 | if (!desc || !*desc) |
| 250 | goto error; |
| 251 | |
| 252 | desclen = strlen(desc) + 1; |
| 253 | quotalen = desclen + type->def_datalen; |
| 254 | |
| 255 | /* get hold of the key tracking for this user */ |
Serge E. Hallyn | 1d1e975 | 2009-02-26 18:27:38 -0600 | [diff] [blame] | 256 | user = key_user_lookup(uid, cred->user->user_ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | if (!user) |
| 258 | goto no_memory_1; |
| 259 | |
| 260 | /* check that the user's quota permits allocation of another key and |
| 261 | * its description */ |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 262 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
David Howells | 0b77f5b | 2008-04-29 01:01:32 -0700 | [diff] [blame] | 263 | unsigned maxkeys = (uid == 0) ? |
| 264 | key_quota_root_maxkeys : key_quota_maxkeys; |
| 265 | unsigned maxbytes = (uid == 0) ? |
| 266 | key_quota_root_maxbytes : key_quota_maxbytes; |
| 267 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | spin_lock(&user->lock); |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 269 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
David Howells | 0b77f5b | 2008-04-29 01:01:32 -0700 | [diff] [blame] | 270 | if (user->qnkeys + 1 >= maxkeys || |
| 271 | user->qnbytes + quotalen >= maxbytes || |
| 272 | user->qnbytes + quotalen < user->qnbytes) |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 273 | goto no_quota; |
| 274 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | |
| 276 | user->qnkeys++; |
| 277 | user->qnbytes += quotalen; |
| 278 | spin_unlock(&user->lock); |
| 279 | } |
| 280 | |
| 281 | /* allocate and initialise the key and its description */ |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 282 | key = kmem_cache_alloc(key_jar, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | if (!key) |
| 284 | goto no_memory_2; |
| 285 | |
| 286 | if (desc) { |
Eric Sesterhenn | 48ad504 | 2006-12-06 20:33:47 -0800 | [diff] [blame] | 287 | key->description = kmemdup(desc, desclen, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | if (!key->description) |
| 289 | goto no_memory_3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | } |
| 291 | |
| 292 | atomic_set(&key->usage, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | init_rwsem(&key->sem); |
| 294 | key->type = type; |
| 295 | key->user = user; |
| 296 | key->quotalen = quotalen; |
| 297 | key->datalen = type->def_datalen; |
| 298 | key->uid = uid; |
| 299 | key->gid = gid; |
| 300 | key->perm = perm; |
| 301 | key->flags = 0; |
| 302 | key->expiry = 0; |
| 303 | key->payload.data = NULL; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 304 | key->security = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 306 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 307 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | |
| 309 | memset(&key->type_data, 0, sizeof(key->type_data)); |
| 310 | |
| 311 | #ifdef KEY_DEBUGGING |
| 312 | key->magic = KEY_DEBUG_MAGIC; |
| 313 | #endif |
| 314 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 315 | /* let the security module know about the key */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 316 | ret = security_key_alloc(key, cred, flags); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 317 | if (ret < 0) |
| 318 | goto security_error; |
| 319 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | /* publish the key by giving it a serial number */ |
| 321 | atomic_inc(&user->nkeys); |
| 322 | key_alloc_serial(key); |
| 323 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 324 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | return key; |
| 326 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 327 | security_error: |
| 328 | kfree(key->description); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | kmem_cache_free(key_jar, key); |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 330 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | spin_lock(&user->lock); |
| 332 | user->qnkeys--; |
| 333 | user->qnbytes -= quotalen; |
| 334 | spin_unlock(&user->lock); |
| 335 | } |
| 336 | key_user_put(user); |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 337 | key = ERR_PTR(ret); |
| 338 | goto error; |
| 339 | |
| 340 | no_memory_3: |
| 341 | kmem_cache_free(key_jar, key); |
| 342 | no_memory_2: |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 343 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 344 | spin_lock(&user->lock); |
| 345 | user->qnkeys--; |
| 346 | user->qnbytes -= quotalen; |
| 347 | spin_unlock(&user->lock); |
| 348 | } |
| 349 | key_user_put(user); |
| 350 | no_memory_1: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | key = ERR_PTR(-ENOMEM); |
| 352 | goto error; |
| 353 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 354 | no_quota: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | spin_unlock(&user->lock); |
| 356 | key_user_put(user); |
| 357 | key = ERR_PTR(-EDQUOT); |
| 358 | goto error; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 359 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | EXPORT_SYMBOL(key_alloc); |
| 361 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 362 | /** |
| 363 | * key_payload_reserve - Adjust data quota reservation for the key's payload |
| 364 | * @key: The key to make the reservation for. |
| 365 | * @datalen: The amount of data payload the caller now wants. |
| 366 | * |
| 367 | * Adjust the amount of the owning user's key data quota that a key reserves. |
| 368 | * If the amount is increased, then -EDQUOT may be returned if there isn't |
| 369 | * enough free quota available. |
| 370 | * |
| 371 | * If successful, 0 is returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | */ |
| 373 | int key_payload_reserve(struct key *key, size_t datalen) |
| 374 | { |
Justin P. Mattock | c5b60b5 | 2010-04-21 00:02:11 -0700 | [diff] [blame] | 375 | int delta = (int)datalen - key->datalen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 376 | int ret = 0; |
| 377 | |
| 378 | key_check(key); |
| 379 | |
| 380 | /* contemplate the quota adjustment */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 381 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
David Howells | 0b77f5b | 2008-04-29 01:01:32 -0700 | [diff] [blame] | 382 | unsigned maxbytes = (key->user->uid == 0) ? |
| 383 | key_quota_root_maxbytes : key_quota_maxbytes; |
| 384 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | spin_lock(&key->user->lock); |
| 386 | |
| 387 | if (delta > 0 && |
David Howells | 0b77f5b | 2008-04-29 01:01:32 -0700 | [diff] [blame] | 388 | (key->user->qnbytes + delta >= maxbytes || |
| 389 | key->user->qnbytes + delta < key->user->qnbytes)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | ret = -EDQUOT; |
| 391 | } |
| 392 | else { |
| 393 | key->user->qnbytes += delta; |
| 394 | key->quotalen += delta; |
| 395 | } |
| 396 | spin_unlock(&key->user->lock); |
| 397 | } |
| 398 | |
| 399 | /* change the recorded data length if that didn't generate an error */ |
| 400 | if (ret == 0) |
| 401 | key->datalen = datalen; |
| 402 | |
| 403 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 404 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | EXPORT_SYMBOL(key_payload_reserve); |
| 406 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 408 | * Instantiate a key and link it into the target keyring atomically. Must be |
| 409 | * called with the target keyring's semaphore writelocked. The target key's |
| 410 | * semaphore need not be locked as instantiation is serialised by |
| 411 | * key_construction_mutex. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | */ |
| 413 | static int __key_instantiate_and_link(struct key *key, |
| 414 | const void *data, |
| 415 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 416 | struct key *keyring, |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 417 | struct key *authkey, |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame^] | 418 | unsigned long *_prealloc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | { |
| 420 | int ret, awaken; |
| 421 | |
| 422 | key_check(key); |
| 423 | key_check(keyring); |
| 424 | |
| 425 | awaken = 0; |
| 426 | ret = -EBUSY; |
| 427 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 428 | mutex_lock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | |
| 430 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 431 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | /* instantiate the key */ |
| 433 | ret = key->type->instantiate(key, data, datalen); |
| 434 | |
| 435 | if (ret == 0) { |
| 436 | /* mark the key as being instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 438 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 440 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | |
| 443 | /* and link it into the destination keyring */ |
| 444 | if (keyring) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 445 | __key_link(keyring, key, _prealloc); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 446 | |
| 447 | /* disable the authorisation key */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 448 | if (authkey) |
| 449 | key_revoke(authkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | } |
| 451 | } |
| 452 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 453 | mutex_unlock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
| 455 | /* wake up anyone waiting for a key to be constructed */ |
| 456 | if (awaken) |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 457 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | |
| 459 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 460 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 462 | /** |
| 463 | * key_instantiate_and_link - Instantiate a key and link it into the keyring. |
| 464 | * @key: The key to instantiate. |
| 465 | * @data: The data to use to instantiate the keyring. |
| 466 | * @datalen: The length of @data. |
| 467 | * @keyring: Keyring to create a link in on success (or NULL). |
| 468 | * @authkey: The authorisation token permitting instantiation. |
| 469 | * |
| 470 | * Instantiate a key that's in the uninstantiated state using the provided data |
| 471 | * and, if successful, link it in to the destination keyring if one is |
| 472 | * supplied. |
| 473 | * |
| 474 | * If successful, 0 is returned, the authorisation token is revoked and anyone |
| 475 | * waiting for the key is woken up. If the key was already instantiated, |
| 476 | * -EBUSY will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | */ |
| 478 | int key_instantiate_and_link(struct key *key, |
| 479 | const void *data, |
| 480 | size_t datalen, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 481 | struct key *keyring, |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 482 | struct key *authkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | { |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame^] | 484 | unsigned long prealloc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | int ret; |
| 486 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 487 | if (keyring) { |
| 488 | ret = __key_link_begin(keyring, key->type, key->description, |
| 489 | &prealloc); |
| 490 | if (ret < 0) |
| 491 | return ret; |
| 492 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 494 | ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey, |
| 495 | &prealloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | |
| 497 | if (keyring) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 498 | __key_link_end(keyring, key->type, prealloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | |
| 500 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 501 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | |
| 503 | EXPORT_SYMBOL(key_instantiate_and_link); |
| 504 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 505 | /** |
| 506 | * key_negate_and_link - Negatively instantiate a key and link it into the keyring. |
| 507 | * @key: The key to instantiate. |
| 508 | * @timeout: The timeout on the negative key. |
| 509 | * @keyring: Keyring to create a link in on success (or NULL). |
| 510 | * @authkey: The authorisation token permitting instantiation. |
| 511 | * |
| 512 | * Negatively instantiate a key that's in the uninstantiated state and, if |
| 513 | * successful, set its timeout and link it in to the destination keyring if one |
| 514 | * is supplied. The key and any links to the key will be automatically garbage |
| 515 | * collected after the timeout expires. |
| 516 | * |
| 517 | * Negative keys are used to rate limit repeated request_key() calls by causing |
| 518 | * them to return -ENOKEY until the negative key expires. |
| 519 | * |
| 520 | * If successful, 0 is returned, the authorisation token is revoked and anyone |
| 521 | * waiting for the key is woken up. If the key was already instantiated, |
| 522 | * -EBUSY will be returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | */ |
| 524 | int key_negate_and_link(struct key *key, |
| 525 | unsigned timeout, |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 526 | struct key *keyring, |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 527 | struct key *authkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | { |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame^] | 529 | unsigned long prealloc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | struct timespec now; |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 531 | int ret, awaken, link_ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | |
| 533 | key_check(key); |
| 534 | key_check(keyring); |
| 535 | |
| 536 | awaken = 0; |
| 537 | ret = -EBUSY; |
| 538 | |
| 539 | if (keyring) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 540 | link_ret = __key_link_begin(keyring, key->type, |
| 541 | key->description, &prealloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 543 | mutex_lock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | |
| 545 | /* can't instantiate twice */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 546 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | /* mark the key as being negatively instantiated */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | atomic_inc(&key->user->nikeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 549 | set_bit(KEY_FLAG_NEGATIVE, &key->flags); |
| 550 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | now = current_kernel_time(); |
| 552 | key->expiry = now.tv_sec + timeout; |
David Howells | c08ef80 | 2009-09-14 17:26:13 +0100 | [diff] [blame] | 553 | key_schedule_gc(key->expiry + key_gc_delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 555 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | awaken = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | ret = 0; |
| 559 | |
| 560 | /* and link it into the destination keyring */ |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 561 | if (keyring && link_ret == 0) |
| 562 | __key_link(keyring, key, &prealloc); |
David Howells | 3e30148 | 2005-06-23 22:00:56 -0700 | [diff] [blame] | 563 | |
| 564 | /* disable the authorisation key */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 565 | if (authkey) |
| 566 | key_revoke(authkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | } |
| 568 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 569 | mutex_unlock(&key_construction_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | |
| 571 | if (keyring) |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 572 | __key_link_end(keyring, key->type, prealloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | |
| 574 | /* wake up anyone waiting for a key to be constructed */ |
| 575 | if (awaken) |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 576 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 578 | return ret == 0 ? link_ret : ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 579 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | |
| 581 | EXPORT_SYMBOL(key_negate_and_link); |
| 582 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 584 | * Garbage collect keys in process context so that we don't have to disable |
| 585 | * interrupts all over the place. |
| 586 | * |
| 587 | * key_put() schedules this rather than trying to do the cleanup itself, which |
| 588 | * means key_put() doesn't have to sleep. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 590 | static void key_cleanup(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | { |
| 592 | struct rb_node *_n; |
| 593 | struct key *key; |
| 594 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 595 | go_again: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | /* look for a dead key in the tree */ |
| 597 | spin_lock(&key_serial_lock); |
| 598 | |
| 599 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 600 | key = rb_entry(_n, struct key, serial_node); |
| 601 | |
| 602 | if (atomic_read(&key->usage) == 0) |
| 603 | goto found_dead_key; |
| 604 | } |
| 605 | |
| 606 | spin_unlock(&key_serial_lock); |
| 607 | return; |
| 608 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 609 | found_dead_key: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | /* we found a dead key - once we've removed it from the tree, we can |
| 611 | * drop the lock */ |
| 612 | rb_erase(&key->serial_node, &key_serial_tree); |
| 613 | spin_unlock(&key_serial_lock); |
| 614 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 615 | key_check(key); |
| 616 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 617 | security_key_free(key); |
| 618 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | /* deal with the user's key tracking and quota */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 620 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | spin_lock(&key->user->lock); |
| 622 | key->user->qnkeys--; |
| 623 | key->user->qnbytes -= key->quotalen; |
| 624 | spin_unlock(&key->user->lock); |
| 625 | } |
| 626 | |
| 627 | atomic_dec(&key->user->nkeys); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 628 | if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | atomic_dec(&key->user->nikeys); |
| 630 | |
| 631 | key_user_put(key->user); |
| 632 | |
| 633 | /* now throw away the key memory */ |
| 634 | if (key->type->destroy) |
| 635 | key->type->destroy(key); |
| 636 | |
| 637 | kfree(key->description); |
| 638 | |
| 639 | #ifdef KEY_DEBUGGING |
| 640 | key->magic = KEY_DEBUG_MAGIC_X; |
| 641 | #endif |
| 642 | kmem_cache_free(key_jar, key); |
| 643 | |
| 644 | /* there may, of course, be more than one key to destroy */ |
| 645 | goto go_again; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 646 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 648 | /** |
| 649 | * key_put - Discard a reference to a key. |
| 650 | * @key: The key to discard a reference from. |
| 651 | * |
| 652 | * Discard a reference to a key, and when all the references are gone, we |
| 653 | * schedule the cleanup task to come and pull it out of the tree in process |
| 654 | * context at some later time. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | */ |
| 656 | void key_put(struct key *key) |
| 657 | { |
| 658 | if (key) { |
| 659 | key_check(key); |
| 660 | |
| 661 | if (atomic_dec_and_test(&key->usage)) |
| 662 | schedule_work(&key_cleanup_task); |
| 663 | } |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 664 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | EXPORT_SYMBOL(key_put); |
| 666 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 668 | * Find a key by its serial number. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | */ |
| 670 | struct key *key_lookup(key_serial_t id) |
| 671 | { |
| 672 | struct rb_node *n; |
| 673 | struct key *key; |
| 674 | |
| 675 | spin_lock(&key_serial_lock); |
| 676 | |
| 677 | /* search the tree for the specified key */ |
| 678 | n = key_serial_tree.rb_node; |
| 679 | while (n) { |
| 680 | key = rb_entry(n, struct key, serial_node); |
| 681 | |
| 682 | if (id < key->serial) |
| 683 | n = n->rb_left; |
| 684 | else if (id > key->serial) |
| 685 | n = n->rb_right; |
| 686 | else |
| 687 | goto found; |
| 688 | } |
| 689 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 690 | not_found: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | key = ERR_PTR(-ENOKEY); |
| 692 | goto error; |
| 693 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 694 | found: |
David Howells | 5593122 | 2009-09-02 09:13:45 +0100 | [diff] [blame] | 695 | /* pretend it doesn't exist if it is awaiting deletion */ |
| 696 | if (atomic_read(&key->usage) == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | goto not_found; |
| 698 | |
| 699 | /* this races with key_put(), but that doesn't matter since key_put() |
| 700 | * doesn't actually change the key |
| 701 | */ |
| 702 | atomic_inc(&key->usage); |
| 703 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 704 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | spin_unlock(&key_serial_lock); |
| 706 | return key; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 707 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 710 | * Find and lock the specified key type against removal. |
| 711 | * |
| 712 | * We return with the sem read-locked if successful. If the type wasn't |
| 713 | * available -ENOKEY is returned instead. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | */ |
| 715 | struct key_type *key_type_lookup(const char *type) |
| 716 | { |
| 717 | struct key_type *ktype; |
| 718 | |
| 719 | down_read(&key_types_sem); |
| 720 | |
| 721 | /* look up the key type to see if it's one of the registered kernel |
| 722 | * types */ |
| 723 | list_for_each_entry(ktype, &key_types_list, link) { |
| 724 | if (strcmp(ktype->name, type) == 0) |
| 725 | goto found_kernel_type; |
| 726 | } |
| 727 | |
| 728 | up_read(&key_types_sem); |
| 729 | ktype = ERR_PTR(-ENOKEY); |
| 730 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 731 | found_kernel_type: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | return ktype; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 733 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 736 | * Unlock a key type locked by key_type_lookup(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | */ |
| 738 | void key_type_put(struct key_type *ktype) |
| 739 | { |
| 740 | up_read(&key_types_sem); |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 741 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 744 | * Attempt to update an existing key. |
| 745 | * |
| 746 | * The key is given to us with an incremented refcount that we need to discard |
| 747 | * if we get an error. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 749 | static inline key_ref_t __key_update(key_ref_t key_ref, |
| 750 | const void *payload, size_t plen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 752 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | int ret; |
| 754 | |
| 755 | /* need write permission on the key to update it */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 756 | ret = key_permission(key_ref, KEY_WRITE); |
| 757 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | goto error; |
| 759 | |
| 760 | ret = -EEXIST; |
| 761 | if (!key->type->update) |
| 762 | goto error; |
| 763 | |
| 764 | down_write(&key->sem); |
| 765 | |
| 766 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 767 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 769 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | |
| 771 | up_write(&key->sem); |
| 772 | |
| 773 | if (ret < 0) |
| 774 | goto error; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 775 | out: |
| 776 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 778 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 780 | key_ref = ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | goto out; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 782 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 784 | /** |
| 785 | * key_create_or_update - Update or create and instantiate a key. |
| 786 | * @keyring_ref: A pointer to the destination keyring with possession flag. |
| 787 | * @type: The type of key. |
| 788 | * @description: The searchable description for the key. |
| 789 | * @payload: The data to use to instantiate or update the key. |
| 790 | * @plen: The length of @payload. |
| 791 | * @perm: The permissions mask for a new key. |
| 792 | * @flags: The quota flags for a new key. |
| 793 | * |
| 794 | * Search the destination keyring for a key of the same description and if one |
| 795 | * is found, update it, otherwise create and instantiate a new one and create a |
| 796 | * link to it from that keyring. |
| 797 | * |
| 798 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be |
| 799 | * concocted. |
| 800 | * |
| 801 | * Returns a pointer to the new key if successful, -ENODEV if the key type |
| 802 | * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the |
| 803 | * caller isn't permitted to modify the keyring or the LSM did not permit |
| 804 | * creation of the key. |
| 805 | * |
| 806 | * On success, the possession flag from the keyring ref will be tacked on to |
| 807 | * the key ref before it is returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 809 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
| 810 | const char *type, |
| 811 | const char *description, |
| 812 | const void *payload, |
| 813 | size_t plen, |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 814 | key_perm_t perm, |
David Howells | 7e047ef | 2006-06-26 00:24:50 -0700 | [diff] [blame] | 815 | unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 816 | { |
David Howells | ceb73c1 | 2011-01-25 16:34:28 +0000 | [diff] [blame^] | 817 | unsigned long prealloc; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 818 | const struct cred *cred = current_cred(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | struct key_type *ktype; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 820 | struct key *keyring, *key = NULL; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 821 | key_ref_t key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | int ret; |
| 823 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | /* look up the key type to see if it's one of the registered kernel |
| 825 | * types */ |
| 826 | ktype = key_type_lookup(type); |
| 827 | if (IS_ERR(ktype)) { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 828 | key_ref = ERR_PTR(-ENODEV); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | goto error; |
| 830 | } |
| 831 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 832 | key_ref = ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | if (!ktype->match || !ktype->instantiate) |
| 834 | goto error_2; |
| 835 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 836 | keyring = key_ref_to_ptr(keyring_ref); |
| 837 | |
| 838 | key_check(keyring); |
| 839 | |
David Howells | c3a9d65 | 2006-04-10 15:15:21 +0100 | [diff] [blame] | 840 | key_ref = ERR_PTR(-ENOTDIR); |
| 841 | if (keyring->type != &key_type_keyring) |
| 842 | goto error_2; |
| 843 | |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 844 | ret = __key_link_begin(keyring, ktype, description, &prealloc); |
| 845 | if (ret < 0) |
| 846 | goto error_2; |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 847 | |
| 848 | /* if we're going to allocate a new key, we're going to have |
| 849 | * to modify the keyring */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 850 | ret = key_permission(keyring_ref, KEY_WRITE); |
| 851 | if (ret < 0) { |
| 852 | key_ref = ERR_PTR(ret); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 853 | goto error_3; |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 854 | } |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 855 | |
David Howells | 1d9b7d9 | 2006-03-25 03:06:52 -0800 | [diff] [blame] | 856 | /* if it's possible to update this type of key, search for an existing |
| 857 | * key of the same type and description in the destination keyring and |
| 858 | * update that instead if possible |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 859 | */ |
David Howells | 1d9b7d9 | 2006-03-25 03:06:52 -0800 | [diff] [blame] | 860 | if (ktype->update) { |
| 861 | key_ref = __keyring_search_one(keyring_ref, ktype, description, |
| 862 | 0); |
| 863 | if (!IS_ERR(key_ref)) |
| 864 | goto found_matching_key; |
| 865 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 867 | /* if the client doesn't provide, decide on the permissions we want */ |
| 868 | if (perm == KEY_PERM_UNDEF) { |
| 869 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; |
| 870 | perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 872 | if (ktype->read) |
| 873 | perm |= KEY_POS_READ | KEY_USR_READ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | |
Arun Raghavan | 6b79ccb | 2008-04-29 01:01:28 -0700 | [diff] [blame] | 875 | if (ktype == &key_type_keyring || ktype->update) |
| 876 | perm |= KEY_USR_WRITE; |
| 877 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | |
| 879 | /* allocate a new key */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 880 | key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred, |
| 881 | perm, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | if (IS_ERR(key)) { |
David Howells | e231c2e | 2008-02-07 00:15:26 -0800 | [diff] [blame] | 883 | key_ref = ERR_CAST(key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | goto error_3; |
| 885 | } |
| 886 | |
| 887 | /* instantiate it and link it into the target keyring */ |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 888 | ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL, |
| 889 | &prealloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 890 | if (ret < 0) { |
| 891 | key_put(key); |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 892 | key_ref = ERR_PTR(ret); |
| 893 | goto error_3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | } |
| 895 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 896 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
| 897 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | error_3: |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 899 | __key_link_end(keyring, ktype, prealloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 900 | error_2: |
| 901 | key_type_put(ktype); |
| 902 | error: |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 903 | return key_ref; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 904 | |
| 905 | found_matching_key: |
| 906 | /* we found a matching key, so we're going to try to update it |
| 907 | * - we can drop the locks first as we have the key pinned |
| 908 | */ |
David Howells | f70e2e0 | 2010-04-30 14:32:39 +0100 | [diff] [blame] | 909 | __key_link_end(keyring, ktype, prealloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 910 | key_type_put(ktype); |
| 911 | |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 912 | key_ref = __key_update(key_ref, payload, plen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 913 | goto error; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 914 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | EXPORT_SYMBOL(key_create_or_update); |
| 916 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 917 | /** |
| 918 | * key_update - Update a key's contents. |
| 919 | * @key_ref: The pointer (plus possession flag) to the key. |
| 920 | * @payload: The data to be used to update the key. |
| 921 | * @plen: The length of @payload. |
| 922 | * |
| 923 | * Attempt to update the contents of a key with the given payload data. The |
| 924 | * caller must be granted Write permission on the key. Negative keys can be |
| 925 | * instantiated by this method. |
| 926 | * |
| 927 | * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key |
| 928 | * type does not support updating. The key type may return other errors. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | */ |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 930 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 931 | { |
David Howells | 664cceb | 2005-09-28 17:03:15 +0100 | [diff] [blame] | 932 | struct key *key = key_ref_to_ptr(key_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | int ret; |
| 934 | |
| 935 | key_check(key); |
| 936 | |
| 937 | /* the key must be writable */ |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 938 | ret = key_permission(key_ref, KEY_WRITE); |
| 939 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 940 | goto error; |
| 941 | |
| 942 | /* attempt to update it if supported */ |
| 943 | ret = -EOPNOTSUPP; |
| 944 | if (key->type->update) { |
| 945 | down_write(&key->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | |
David Howells | 29db919 | 2005-10-30 15:02:44 -0800 | [diff] [blame] | 947 | ret = key->type->update(key, payload, plen); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 948 | if (ret == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | /* updating a negative key instantiates it */ |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 950 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 951 | |
| 952 | up_write(&key->sem); |
| 953 | } |
| 954 | |
| 955 | error: |
| 956 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 957 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | EXPORT_SYMBOL(key_update); |
| 959 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 960 | /** |
| 961 | * key_revoke - Revoke a key. |
| 962 | * @key: The key to be revoked. |
| 963 | * |
| 964 | * Mark a key as being revoked and ask the type to free up its resources. The |
| 965 | * revocation timeout is set and the key and all its links will be |
| 966 | * automatically garbage collected after key_gc_delay amount of time if they |
| 967 | * are not manually dealt with first. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | */ |
| 969 | void key_revoke(struct key *key) |
| 970 | { |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 971 | struct timespec now; |
| 972 | time_t time; |
| 973 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | key_check(key); |
| 975 | |
David Howells | 76181c1 | 2007-10-16 23:29:46 -0700 | [diff] [blame] | 976 | /* make sure no one's trying to change or use the key when we mark it |
| 977 | * - we tell lockdep that we might nest because we might be revoking an |
| 978 | * authorisation key whilst holding the sem on a key we've just |
| 979 | * instantiated |
| 980 | */ |
| 981 | down_write_nested(&key->sem, 1); |
| 982 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) && |
| 983 | key->type->revoke) |
David Howells | 04c567d | 2006-06-22 14:47:18 -0700 | [diff] [blame] | 984 | key->type->revoke(key); |
| 985 | |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 986 | /* set the death time to no more than the expiry time */ |
| 987 | now = current_kernel_time(); |
| 988 | time = now.tv_sec; |
| 989 | if (key->revoked_at == 0 || key->revoked_at > time) { |
| 990 | key->revoked_at = time; |
David Howells | c08ef80 | 2009-09-14 17:26:13 +0100 | [diff] [blame] | 991 | key_schedule_gc(key->revoked_at + key_gc_delay); |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 992 | } |
| 993 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | up_write(&key->sem); |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 995 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | EXPORT_SYMBOL(key_revoke); |
| 997 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 998 | /** |
| 999 | * register_key_type - Register a type of key. |
| 1000 | * @ktype: The new key type. |
| 1001 | * |
| 1002 | * Register a new key type. |
| 1003 | * |
| 1004 | * Returns 0 on success or -EEXIST if a type of this name already exists. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | */ |
| 1006 | int register_key_type(struct key_type *ktype) |
| 1007 | { |
| 1008 | struct key_type *p; |
| 1009 | int ret; |
| 1010 | |
| 1011 | ret = -EEXIST; |
| 1012 | down_write(&key_types_sem); |
| 1013 | |
| 1014 | /* disallow key types with the same name */ |
| 1015 | list_for_each_entry(p, &key_types_list, link) { |
| 1016 | if (strcmp(p->name, ktype->name) == 0) |
| 1017 | goto out; |
| 1018 | } |
| 1019 | |
| 1020 | /* store the type */ |
| 1021 | list_add(&ktype->link, &key_types_list); |
| 1022 | ret = 0; |
| 1023 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1024 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | up_write(&key_types_sem); |
| 1026 | return ret; |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 1027 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1028 | EXPORT_SYMBOL(register_key_type); |
| 1029 | |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1030 | /** |
| 1031 | * unregister_key_type - Unregister a type of key. |
| 1032 | * @ktype: The key type. |
| 1033 | * |
| 1034 | * Unregister a key type and mark all the extant keys of this type as dead. |
| 1035 | * Those keys of this type are then destroyed to get rid of their payloads and |
| 1036 | * they and their links will be garbage collected as soon as possible. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | */ |
| 1038 | void unregister_key_type(struct key_type *ktype) |
| 1039 | { |
| 1040 | struct rb_node *_n; |
| 1041 | struct key *key; |
| 1042 | |
| 1043 | down_write(&key_types_sem); |
| 1044 | |
| 1045 | /* withdraw the key type */ |
| 1046 | list_del_init(&ktype->link); |
| 1047 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1048 | /* mark all the keys of this type dead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | spin_lock(&key_serial_lock); |
| 1050 | |
| 1051 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 1052 | key = rb_entry(_n, struct key, serial_node); |
| 1053 | |
David Howells | f041ae2 | 2009-09-02 09:13:55 +0100 | [diff] [blame] | 1054 | if (key->type == ktype) { |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1055 | key->type = &key_type_dead; |
David Howells | f041ae2 | 2009-09-02 09:13:55 +0100 | [diff] [blame] | 1056 | set_bit(KEY_FLAG_DEAD, &key->flags); |
| 1057 | } |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1058 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1060 | spin_unlock(&key_serial_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1061 | |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1062 | /* make sure everyone revalidates their keys */ |
Paul E. McKenney | b2b1866 | 2005-06-25 14:55:38 -0700 | [diff] [blame] | 1063 | synchronize_rcu(); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1064 | |
| 1065 | /* we should now be able to destroy the payloads of all the keys of |
| 1066 | * this type with impunity */ |
| 1067 | spin_lock(&key_serial_lock); |
| 1068 | |
| 1069 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
| 1070 | key = rb_entry(_n, struct key, serial_node); |
| 1071 | |
| 1072 | if (key->type == ktype) { |
| 1073 | if (ktype->destroy) |
| 1074 | ktype->destroy(key); |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 1075 | memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame] | 1076 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | } |
| 1078 | |
| 1079 | spin_unlock(&key_serial_lock); |
| 1080 | up_write(&key_types_sem); |
| 1081 | |
David Howells | 5d13544 | 2009-09-02 09:14:00 +0100 | [diff] [blame] | 1082 | key_schedule_gc(0); |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 1083 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1084 | EXPORT_SYMBOL(unregister_key_type); |
| 1085 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | /* |
David Howells | 973c9f4 | 2011-01-20 16:38:33 +0000 | [diff] [blame] | 1087 | * Initialise the key management state. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1088 | */ |
| 1089 | void __init key_init(void) |
| 1090 | { |
| 1091 | /* allocate a slab in which we can store keys */ |
| 1092 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1093 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1094 | |
| 1095 | /* add the special key types */ |
| 1096 | list_add_tail(&key_type_keyring.link, &key_types_list); |
| 1097 | list_add_tail(&key_type_dead.link, &key_types_list); |
| 1098 | list_add_tail(&key_type_user.link, &key_types_list); |
| 1099 | |
| 1100 | /* record the root user tracking */ |
| 1101 | rb_link_node(&root_key_user.node, |
| 1102 | NULL, |
| 1103 | &key_user_tree.rb_node); |
| 1104 | |
| 1105 | rb_insert_color(&root_key_user.node, |
| 1106 | &key_user_tree); |
David Howells | a8b17ed | 2011-01-20 16:38:27 +0000 | [diff] [blame] | 1107 | } |