Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* process_keys.c: management of a process's keyrings |
| 2 | * |
| 3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
| 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> |
| 16 | #include <linux/keyctl.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/err.h> |
| 19 | #include <asm/uaccess.h> |
| 20 | #include "internal.h" |
| 21 | |
| 22 | /* session keyring create vs join semaphore */ |
| 23 | static DECLARE_MUTEX(key_session_sem); |
| 24 | |
| 25 | /* the root user's tracking struct */ |
| 26 | struct key_user root_key_user = { |
| 27 | .usage = ATOMIC_INIT(3), |
| 28 | .consq = LIST_HEAD_INIT(root_key_user.consq), |
| 29 | .lock = SPIN_LOCK_UNLOCKED, |
| 30 | .nkeys = ATOMIC_INIT(2), |
| 31 | .nikeys = ATOMIC_INIT(2), |
| 32 | .uid = 0, |
| 33 | }; |
| 34 | |
| 35 | /* the root user's UID keyring */ |
| 36 | struct key root_user_keyring = { |
| 37 | .usage = ATOMIC_INIT(1), |
| 38 | .serial = 2, |
| 39 | .type = &key_type_keyring, |
| 40 | .user = &root_key_user, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | .sem = __RWSEM_INITIALIZER(root_user_keyring.sem), |
| 42 | .perm = KEY_USR_ALL, |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame^] | 43 | .flags = 1 << KEY_FLAG_INSTANTIATED, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | .description = "_uid.0", |
| 45 | #ifdef KEY_DEBUGGING |
| 46 | .magic = KEY_DEBUG_MAGIC, |
| 47 | #endif |
| 48 | }; |
| 49 | |
| 50 | /* the root user's default session keyring */ |
| 51 | struct key root_session_keyring = { |
| 52 | .usage = ATOMIC_INIT(1), |
| 53 | .serial = 1, |
| 54 | .type = &key_type_keyring, |
| 55 | .user = &root_key_user, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | .sem = __RWSEM_INITIALIZER(root_session_keyring.sem), |
| 57 | .perm = KEY_USR_ALL, |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame^] | 58 | .flags = 1 << KEY_FLAG_INSTANTIATED, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | .description = "_uid_ses.0", |
| 60 | #ifdef KEY_DEBUGGING |
| 61 | .magic = KEY_DEBUG_MAGIC, |
| 62 | #endif |
| 63 | }; |
| 64 | |
| 65 | /*****************************************************************************/ |
| 66 | /* |
| 67 | * allocate the keyrings to be associated with a UID |
| 68 | */ |
| 69 | int alloc_uid_keyring(struct user_struct *user) |
| 70 | { |
| 71 | struct key *uid_keyring, *session_keyring; |
| 72 | char buf[20]; |
| 73 | int ret; |
| 74 | |
| 75 | /* concoct a default session keyring */ |
| 76 | sprintf(buf, "_uid_ses.%u", user->uid); |
| 77 | |
| 78 | session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, 0, NULL); |
| 79 | if (IS_ERR(session_keyring)) { |
| 80 | ret = PTR_ERR(session_keyring); |
| 81 | goto error; |
| 82 | } |
| 83 | |
| 84 | /* and a UID specific keyring, pointed to by the default session |
| 85 | * keyring */ |
| 86 | sprintf(buf, "_uid.%u", user->uid); |
| 87 | |
| 88 | uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, 0, |
| 89 | session_keyring); |
| 90 | if (IS_ERR(uid_keyring)) { |
| 91 | key_put(session_keyring); |
| 92 | ret = PTR_ERR(uid_keyring); |
| 93 | goto error; |
| 94 | } |
| 95 | |
| 96 | /* install the keyrings */ |
| 97 | user->uid_keyring = uid_keyring; |
| 98 | user->session_keyring = session_keyring; |
| 99 | ret = 0; |
| 100 | |
| 101 | error: |
| 102 | return ret; |
| 103 | |
| 104 | } /* end alloc_uid_keyring() */ |
| 105 | |
| 106 | /*****************************************************************************/ |
| 107 | /* |
| 108 | * deal with the UID changing |
| 109 | */ |
| 110 | void switch_uid_keyring(struct user_struct *new_user) |
| 111 | { |
| 112 | #if 0 /* do nothing for now */ |
| 113 | struct key *old; |
| 114 | |
| 115 | /* switch to the new user's session keyring if we were running under |
| 116 | * root's default session keyring */ |
| 117 | if (new_user->uid != 0 && |
| 118 | current->session_keyring == &root_session_keyring |
| 119 | ) { |
| 120 | atomic_inc(&new_user->session_keyring->usage); |
| 121 | |
| 122 | task_lock(current); |
| 123 | old = current->session_keyring; |
| 124 | current->session_keyring = new_user->session_keyring; |
| 125 | task_unlock(current); |
| 126 | |
| 127 | key_put(old); |
| 128 | } |
| 129 | #endif |
| 130 | |
| 131 | } /* end switch_uid_keyring() */ |
| 132 | |
| 133 | /*****************************************************************************/ |
| 134 | /* |
| 135 | * install a fresh thread keyring, discarding the old one |
| 136 | */ |
| 137 | int install_thread_keyring(struct task_struct *tsk) |
| 138 | { |
| 139 | struct key *keyring, *old; |
| 140 | char buf[20]; |
| 141 | int ret; |
| 142 | |
| 143 | sprintf(buf, "_tid.%u", tsk->pid); |
| 144 | |
| 145 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL); |
| 146 | if (IS_ERR(keyring)) { |
| 147 | ret = PTR_ERR(keyring); |
| 148 | goto error; |
| 149 | } |
| 150 | |
| 151 | task_lock(tsk); |
| 152 | old = tsk->thread_keyring; |
| 153 | tsk->thread_keyring = keyring; |
| 154 | task_unlock(tsk); |
| 155 | |
| 156 | ret = 0; |
| 157 | |
| 158 | key_put(old); |
| 159 | error: |
| 160 | return ret; |
| 161 | |
| 162 | } /* end install_thread_keyring() */ |
| 163 | |
| 164 | /*****************************************************************************/ |
| 165 | /* |
| 166 | * make sure a process keyring is installed |
| 167 | */ |
| 168 | static int install_process_keyring(struct task_struct *tsk) |
| 169 | { |
| 170 | unsigned long flags; |
| 171 | struct key *keyring; |
| 172 | char buf[20]; |
| 173 | int ret; |
| 174 | |
| 175 | if (!tsk->signal->process_keyring) { |
| 176 | sprintf(buf, "_pid.%u", tsk->tgid); |
| 177 | |
| 178 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL); |
| 179 | if (IS_ERR(keyring)) { |
| 180 | ret = PTR_ERR(keyring); |
| 181 | goto error; |
| 182 | } |
| 183 | |
| 184 | /* attach or swap keyrings */ |
| 185 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
| 186 | if (!tsk->signal->process_keyring) { |
| 187 | tsk->signal->process_keyring = keyring; |
| 188 | keyring = NULL; |
| 189 | } |
| 190 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
| 191 | |
| 192 | key_put(keyring); |
| 193 | } |
| 194 | |
| 195 | ret = 0; |
| 196 | error: |
| 197 | return ret; |
| 198 | |
| 199 | } /* end install_process_keyring() */ |
| 200 | |
| 201 | /*****************************************************************************/ |
| 202 | /* |
| 203 | * install a session keyring, discarding the old one |
| 204 | * - if a keyring is not supplied, an empty one is invented |
| 205 | */ |
| 206 | static int install_session_keyring(struct task_struct *tsk, |
| 207 | struct key *keyring) |
| 208 | { |
| 209 | unsigned long flags; |
| 210 | struct key *old; |
| 211 | char buf[20]; |
| 212 | int ret; |
| 213 | |
| 214 | /* create an empty session keyring */ |
| 215 | if (!keyring) { |
| 216 | sprintf(buf, "_ses.%u", tsk->tgid); |
| 217 | |
| 218 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL); |
| 219 | if (IS_ERR(keyring)) { |
| 220 | ret = PTR_ERR(keyring); |
| 221 | goto error; |
| 222 | } |
| 223 | } |
| 224 | else { |
| 225 | atomic_inc(&keyring->usage); |
| 226 | } |
| 227 | |
| 228 | /* install the keyring */ |
| 229 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
| 230 | old = tsk->signal->session_keyring; |
| 231 | tsk->signal->session_keyring = keyring; |
| 232 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
| 233 | |
| 234 | ret = 0; |
| 235 | |
| 236 | key_put(old); |
| 237 | error: |
| 238 | return ret; |
| 239 | |
| 240 | } /* end install_session_keyring() */ |
| 241 | |
| 242 | /*****************************************************************************/ |
| 243 | /* |
| 244 | * copy the keys in a thread group for fork without CLONE_THREAD |
| 245 | */ |
| 246 | int copy_thread_group_keys(struct task_struct *tsk) |
| 247 | { |
| 248 | unsigned long flags; |
| 249 | |
| 250 | key_check(current->thread_group->session_keyring); |
| 251 | key_check(current->thread_group->process_keyring); |
| 252 | |
| 253 | /* no process keyring yet */ |
| 254 | tsk->signal->process_keyring = NULL; |
| 255 | |
| 256 | /* same session keyring */ |
| 257 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
| 258 | tsk->signal->session_keyring = |
| 259 | key_get(current->signal->session_keyring); |
| 260 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| 261 | |
| 262 | return 0; |
| 263 | |
| 264 | } /* end copy_thread_group_keys() */ |
| 265 | |
| 266 | /*****************************************************************************/ |
| 267 | /* |
| 268 | * copy the keys for fork |
| 269 | */ |
| 270 | int copy_keys(unsigned long clone_flags, struct task_struct *tsk) |
| 271 | { |
| 272 | key_check(tsk->thread_keyring); |
| 273 | |
| 274 | /* no thread keyring yet */ |
| 275 | tsk->thread_keyring = NULL; |
| 276 | return 0; |
| 277 | |
| 278 | } /* end copy_keys() */ |
| 279 | |
| 280 | /*****************************************************************************/ |
| 281 | /* |
| 282 | * dispose of thread group keys upon thread group destruction |
| 283 | */ |
| 284 | void exit_thread_group_keys(struct signal_struct *tg) |
| 285 | { |
| 286 | key_put(tg->session_keyring); |
| 287 | key_put(tg->process_keyring); |
| 288 | |
| 289 | } /* end exit_thread_group_keys() */ |
| 290 | |
| 291 | /*****************************************************************************/ |
| 292 | /* |
| 293 | * dispose of keys upon thread exit |
| 294 | */ |
| 295 | void exit_keys(struct task_struct *tsk) |
| 296 | { |
| 297 | key_put(tsk->thread_keyring); |
| 298 | |
| 299 | } /* end exit_keys() */ |
| 300 | |
| 301 | /*****************************************************************************/ |
| 302 | /* |
| 303 | * deal with execve() |
| 304 | */ |
| 305 | int exec_keys(struct task_struct *tsk) |
| 306 | { |
| 307 | unsigned long flags; |
| 308 | struct key *old; |
| 309 | |
| 310 | /* newly exec'd tasks don't get a thread keyring */ |
| 311 | task_lock(tsk); |
| 312 | old = tsk->thread_keyring; |
| 313 | tsk->thread_keyring = NULL; |
| 314 | task_unlock(tsk); |
| 315 | |
| 316 | key_put(old); |
| 317 | |
| 318 | /* discard the process keyring from a newly exec'd task */ |
| 319 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
| 320 | old = tsk->signal->process_keyring; |
| 321 | tsk->signal->process_keyring = NULL; |
| 322 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
| 323 | |
| 324 | key_put(old); |
| 325 | |
| 326 | return 0; |
| 327 | |
| 328 | } /* end exec_keys() */ |
| 329 | |
| 330 | /*****************************************************************************/ |
| 331 | /* |
| 332 | * deal with SUID programs |
| 333 | * - we might want to make this invent a new session keyring |
| 334 | */ |
| 335 | int suid_keys(struct task_struct *tsk) |
| 336 | { |
| 337 | return 0; |
| 338 | |
| 339 | } /* end suid_keys() */ |
| 340 | |
| 341 | /*****************************************************************************/ |
| 342 | /* |
| 343 | * the filesystem user ID changed |
| 344 | */ |
| 345 | void key_fsuid_changed(struct task_struct *tsk) |
| 346 | { |
| 347 | /* update the ownership of the thread keyring */ |
| 348 | if (tsk->thread_keyring) { |
| 349 | down_write(&tsk->thread_keyring->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | tsk->thread_keyring->uid = tsk->fsuid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | up_write(&tsk->thread_keyring->sem); |
| 352 | } |
| 353 | |
| 354 | } /* end key_fsuid_changed() */ |
| 355 | |
| 356 | /*****************************************************************************/ |
| 357 | /* |
| 358 | * the filesystem group ID changed |
| 359 | */ |
| 360 | void key_fsgid_changed(struct task_struct *tsk) |
| 361 | { |
| 362 | /* update the ownership of the thread keyring */ |
| 363 | if (tsk->thread_keyring) { |
| 364 | down_write(&tsk->thread_keyring->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | tsk->thread_keyring->gid = tsk->fsgid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | up_write(&tsk->thread_keyring->sem); |
| 367 | } |
| 368 | |
| 369 | } /* end key_fsgid_changed() */ |
| 370 | |
| 371 | /*****************************************************************************/ |
| 372 | /* |
| 373 | * search the process keyrings for the first matching key |
| 374 | * - we use the supplied match function to see if the description (or other |
| 375 | * feature of interest) matches |
| 376 | * - we return -EAGAIN if we didn't find any matching key |
| 377 | * - we return -ENOKEY if we found only negative matching keys |
| 378 | */ |
| 379 | struct key *search_process_keyrings_aux(struct key_type *type, |
| 380 | const void *description, |
| 381 | key_match_func_t match) |
| 382 | { |
| 383 | struct task_struct *tsk = current; |
| 384 | unsigned long flags; |
| 385 | struct key *key, *ret, *err, *tmp; |
| 386 | |
| 387 | /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were |
| 388 | * searchable, but we failed to find a key or we found a negative key; |
| 389 | * otherwise we want to return a sample error (probably -EACCES) if |
| 390 | * none of the keyrings were searchable |
| 391 | * |
| 392 | * in terms of priority: success > -ENOKEY > -EAGAIN > other error |
| 393 | */ |
| 394 | key = NULL; |
| 395 | ret = NULL; |
| 396 | err = ERR_PTR(-EAGAIN); |
| 397 | |
| 398 | /* search the thread keyring first */ |
| 399 | if (tsk->thread_keyring) { |
| 400 | key = keyring_search_aux(tsk->thread_keyring, type, |
| 401 | description, match); |
| 402 | if (!IS_ERR(key)) |
| 403 | goto found; |
| 404 | |
| 405 | switch (PTR_ERR(key)) { |
| 406 | case -EAGAIN: /* no key */ |
| 407 | if (ret) |
| 408 | break; |
| 409 | case -ENOKEY: /* negative key */ |
| 410 | ret = key; |
| 411 | break; |
| 412 | default: |
| 413 | err = key; |
| 414 | break; |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | /* search the process keyring second */ |
| 419 | if (tsk->signal->process_keyring) { |
| 420 | key = keyring_search_aux(tsk->signal->process_keyring, |
| 421 | type, description, match); |
| 422 | if (!IS_ERR(key)) |
| 423 | goto found; |
| 424 | |
| 425 | switch (PTR_ERR(key)) { |
| 426 | case -EAGAIN: /* no key */ |
| 427 | if (ret) |
| 428 | break; |
| 429 | case -ENOKEY: /* negative key */ |
| 430 | ret = key; |
| 431 | break; |
| 432 | default: |
| 433 | err = key; |
| 434 | break; |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | /* search the session keyring last */ |
| 439 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
| 440 | |
| 441 | tmp = tsk->signal->session_keyring; |
| 442 | if (!tmp) |
| 443 | tmp = tsk->user->session_keyring; |
| 444 | atomic_inc(&tmp->usage); |
| 445 | |
| 446 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
| 447 | |
| 448 | key = keyring_search_aux(tmp, type, description, match); |
| 449 | key_put(tmp); |
| 450 | if (!IS_ERR(key)) |
| 451 | goto found; |
| 452 | |
| 453 | switch (PTR_ERR(key)) { |
| 454 | case -EAGAIN: /* no key */ |
| 455 | if (ret) |
| 456 | break; |
| 457 | case -ENOKEY: /* negative key */ |
| 458 | ret = key; |
| 459 | break; |
| 460 | default: |
| 461 | err = key; |
| 462 | break; |
| 463 | } |
| 464 | |
| 465 | /* no key - decide on the error we're going to go for */ |
| 466 | key = ret ? ret : err; |
| 467 | |
| 468 | found: |
| 469 | return key; |
| 470 | |
| 471 | } /* end search_process_keyrings_aux() */ |
| 472 | |
| 473 | /*****************************************************************************/ |
| 474 | /* |
| 475 | * search the process keyrings for the first matching key |
| 476 | * - we return -EAGAIN if we didn't find any matching key |
| 477 | * - we return -ENOKEY if we found only negative matching keys |
| 478 | */ |
| 479 | struct key *search_process_keyrings(struct key_type *type, |
| 480 | const char *description) |
| 481 | { |
| 482 | return search_process_keyrings_aux(type, description, type->match); |
| 483 | |
| 484 | } /* end search_process_keyrings() */ |
| 485 | |
| 486 | /*****************************************************************************/ |
| 487 | /* |
| 488 | * lookup a key given a key ID from userspace with a given permissions mask |
| 489 | * - don't create special keyrings unless so requested |
| 490 | * - partially constructed keys aren't found unless requested |
| 491 | */ |
| 492 | struct key *lookup_user_key(key_serial_t id, int create, int partial, |
| 493 | key_perm_t perm) |
| 494 | { |
| 495 | struct task_struct *tsk = current; |
| 496 | unsigned long flags; |
| 497 | struct key *key; |
| 498 | int ret; |
| 499 | |
| 500 | key = ERR_PTR(-ENOKEY); |
| 501 | |
| 502 | switch (id) { |
| 503 | case KEY_SPEC_THREAD_KEYRING: |
| 504 | if (!tsk->thread_keyring) { |
| 505 | if (!create) |
| 506 | goto error; |
| 507 | |
| 508 | ret = install_thread_keyring(tsk); |
| 509 | if (ret < 0) { |
| 510 | key = ERR_PTR(ret); |
| 511 | goto error; |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | key = tsk->thread_keyring; |
| 516 | atomic_inc(&key->usage); |
| 517 | break; |
| 518 | |
| 519 | case KEY_SPEC_PROCESS_KEYRING: |
| 520 | if (!tsk->signal->process_keyring) { |
| 521 | if (!create) |
| 522 | goto error; |
| 523 | |
| 524 | ret = install_process_keyring(tsk); |
| 525 | if (ret < 0) { |
| 526 | key = ERR_PTR(ret); |
| 527 | goto error; |
| 528 | } |
| 529 | } |
| 530 | |
| 531 | key = tsk->signal->process_keyring; |
| 532 | atomic_inc(&key->usage); |
| 533 | break; |
| 534 | |
| 535 | case KEY_SPEC_SESSION_KEYRING: |
| 536 | if (!tsk->signal->session_keyring) { |
| 537 | /* always install a session keyring upon access if one |
| 538 | * doesn't exist yet */ |
| 539 | ret = install_session_keyring( |
| 540 | tsk, tsk->user->session_keyring); |
| 541 | if (ret < 0) |
| 542 | goto error; |
| 543 | } |
| 544 | |
| 545 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
| 546 | key = tsk->signal->session_keyring; |
| 547 | atomic_inc(&key->usage); |
| 548 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
| 549 | break; |
| 550 | |
| 551 | case KEY_SPEC_USER_KEYRING: |
| 552 | key = tsk->user->uid_keyring; |
| 553 | atomic_inc(&key->usage); |
| 554 | break; |
| 555 | |
| 556 | case KEY_SPEC_USER_SESSION_KEYRING: |
| 557 | key = tsk->user->session_keyring; |
| 558 | atomic_inc(&key->usage); |
| 559 | break; |
| 560 | |
| 561 | case KEY_SPEC_GROUP_KEYRING: |
| 562 | /* group keyrings are not yet supported */ |
| 563 | key = ERR_PTR(-EINVAL); |
| 564 | goto error; |
| 565 | |
| 566 | default: |
| 567 | key = ERR_PTR(-EINVAL); |
| 568 | if (id < 1) |
| 569 | goto error; |
| 570 | |
| 571 | key = key_lookup(id); |
| 572 | if (IS_ERR(key)) |
| 573 | goto error; |
| 574 | break; |
| 575 | } |
| 576 | |
| 577 | /* check the status and permissions */ |
| 578 | if (perm) { |
| 579 | ret = key_validate(key); |
| 580 | if (ret < 0) |
| 581 | goto invalid_key; |
| 582 | } |
| 583 | |
| 584 | ret = -EIO; |
David Howells | 76d8aea | 2005-06-23 22:00:49 -0700 | [diff] [blame^] | 585 | if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | goto invalid_key; |
| 587 | |
| 588 | ret = -EACCES; |
| 589 | if (!key_permission(key, perm)) |
| 590 | goto invalid_key; |
| 591 | |
| 592 | error: |
| 593 | return key; |
| 594 | |
| 595 | invalid_key: |
| 596 | key_put(key); |
| 597 | key = ERR_PTR(ret); |
| 598 | goto error; |
| 599 | |
| 600 | } /* end lookup_user_key() */ |
| 601 | |
| 602 | /*****************************************************************************/ |
| 603 | /* |
| 604 | * join the named keyring as the session keyring if possible, or attempt to |
| 605 | * create a new one of that name if not |
| 606 | * - if the name is NULL, an empty anonymous keyring is installed instead |
| 607 | * - named session keyring joining is done with a semaphore held |
| 608 | */ |
| 609 | long join_session_keyring(const char *name) |
| 610 | { |
| 611 | struct task_struct *tsk = current; |
| 612 | unsigned long flags; |
| 613 | struct key *keyring; |
| 614 | long ret; |
| 615 | |
| 616 | /* if no name is provided, install an anonymous keyring */ |
| 617 | if (!name) { |
| 618 | ret = install_session_keyring(tsk, NULL); |
| 619 | if (ret < 0) |
| 620 | goto error; |
| 621 | |
| 622 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
| 623 | ret = tsk->signal->session_keyring->serial; |
| 624 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
| 625 | goto error; |
| 626 | } |
| 627 | |
| 628 | /* allow the user to join or create a named keyring */ |
| 629 | down(&key_session_sem); |
| 630 | |
| 631 | /* look for an existing keyring of this name */ |
| 632 | keyring = find_keyring_by_name(name, 0); |
| 633 | if (PTR_ERR(keyring) == -ENOKEY) { |
| 634 | /* not found - try and create a new one */ |
| 635 | keyring = keyring_alloc(name, tsk->uid, tsk->gid, 0, NULL); |
| 636 | if (IS_ERR(keyring)) { |
| 637 | ret = PTR_ERR(keyring); |
| 638 | goto error; |
| 639 | } |
| 640 | } |
| 641 | else if (IS_ERR(keyring)) { |
| 642 | ret = PTR_ERR(keyring); |
| 643 | goto error2; |
| 644 | } |
| 645 | |
| 646 | /* we've got a keyring - now to install it */ |
| 647 | ret = install_session_keyring(tsk, keyring); |
| 648 | if (ret < 0) |
| 649 | goto error2; |
| 650 | |
| 651 | ret = keyring->serial; |
| 652 | key_put(keyring); |
| 653 | |
| 654 | error2: |
| 655 | up(&key_session_sem); |
| 656 | error: |
| 657 | return ret; |
| 658 | |
| 659 | } /* end join_session_keyring() */ |