| 1 |
62 |
marcus.erl |
/* process_keys.c: management of a process's keyrings
|
| 2 |
|
|
*
|
| 3 |
|
|
* Copyright (C) 2004-5 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 <linux/mutex.h>
|
| 20 |
|
|
#include <asm/uaccess.h>
|
| 21 |
|
|
#include "internal.h"
|
| 22 |
|
|
|
| 23 |
|
|
/* session keyring create vs join semaphore */
|
| 24 |
|
|
static DEFINE_MUTEX(key_session_mutex);
|
| 25 |
|
|
|
| 26 |
|
|
/* the root user's tracking struct */
|
| 27 |
|
|
struct key_user root_key_user = {
|
| 28 |
|
|
.usage = ATOMIC_INIT(3),
|
| 29 |
|
|
.cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock),
|
| 30 |
|
|
.lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock),
|
| 31 |
|
|
.nkeys = ATOMIC_INIT(2),
|
| 32 |
|
|
.nikeys = ATOMIC_INIT(2),
|
| 33 |
|
|
.uid = 0,
|
| 34 |
|
|
};
|
| 35 |
|
|
|
| 36 |
|
|
/* the root user's UID keyring */
|
| 37 |
|
|
struct key root_user_keyring = {
|
| 38 |
|
|
.usage = ATOMIC_INIT(1),
|
| 39 |
|
|
.serial = 2,
|
| 40 |
|
|
.type = &key_type_keyring,
|
| 41 |
|
|
.user = &root_key_user,
|
| 42 |
|
|
.sem = __RWSEM_INITIALIZER(root_user_keyring.sem),
|
| 43 |
|
|
.perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
|
| 44 |
|
|
.flags = 1 << KEY_FLAG_INSTANTIATED,
|
| 45 |
|
|
.description = "_uid.0",
|
| 46 |
|
|
#ifdef KEY_DEBUGGING
|
| 47 |
|
|
.magic = KEY_DEBUG_MAGIC,
|
| 48 |
|
|
#endif
|
| 49 |
|
|
};
|
| 50 |
|
|
|
| 51 |
|
|
/* the root user's default session keyring */
|
| 52 |
|
|
struct key root_session_keyring = {
|
| 53 |
|
|
.usage = ATOMIC_INIT(1),
|
| 54 |
|
|
.serial = 1,
|
| 55 |
|
|
.type = &key_type_keyring,
|
| 56 |
|
|
.user = &root_key_user,
|
| 57 |
|
|
.sem = __RWSEM_INITIALIZER(root_session_keyring.sem),
|
| 58 |
|
|
.perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
|
| 59 |
|
|
.flags = 1 << KEY_FLAG_INSTANTIATED,
|
| 60 |
|
|
.description = "_uid_ses.0",
|
| 61 |
|
|
#ifdef KEY_DEBUGGING
|
| 62 |
|
|
.magic = KEY_DEBUG_MAGIC,
|
| 63 |
|
|
#endif
|
| 64 |
|
|
};
|
| 65 |
|
|
|
| 66 |
|
|
/*****************************************************************************/
|
| 67 |
|
|
/*
|
| 68 |
|
|
* allocate the keyrings to be associated with a UID
|
| 69 |
|
|
*/
|
| 70 |
|
|
int alloc_uid_keyring(struct user_struct *user,
|
| 71 |
|
|
struct task_struct *ctx)
|
| 72 |
|
|
{
|
| 73 |
|
|
struct key *uid_keyring, *session_keyring;
|
| 74 |
|
|
char buf[20];
|
| 75 |
|
|
int ret;
|
| 76 |
|
|
|
| 77 |
|
|
/* concoct a default session keyring */
|
| 78 |
|
|
sprintf(buf, "_uid_ses.%u", user->uid);
|
| 79 |
|
|
|
| 80 |
|
|
session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx,
|
| 81 |
|
|
KEY_ALLOC_IN_QUOTA, NULL);
|
| 82 |
|
|
if (IS_ERR(session_keyring)) {
|
| 83 |
|
|
ret = PTR_ERR(session_keyring);
|
| 84 |
|
|
goto error;
|
| 85 |
|
|
}
|
| 86 |
|
|
|
| 87 |
|
|
/* and a UID specific keyring, pointed to by the default session
|
| 88 |
|
|
* keyring */
|
| 89 |
|
|
sprintf(buf, "_uid.%u", user->uid);
|
| 90 |
|
|
|
| 91 |
|
|
uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx,
|
| 92 |
|
|
KEY_ALLOC_IN_QUOTA, session_keyring);
|
| 93 |
|
|
if (IS_ERR(uid_keyring)) {
|
| 94 |
|
|
key_put(session_keyring);
|
| 95 |
|
|
ret = PTR_ERR(uid_keyring);
|
| 96 |
|
|
goto error;
|
| 97 |
|
|
}
|
| 98 |
|
|
|
| 99 |
|
|
/* install the keyrings */
|
| 100 |
|
|
user->uid_keyring = uid_keyring;
|
| 101 |
|
|
user->session_keyring = session_keyring;
|
| 102 |
|
|
ret = 0;
|
| 103 |
|
|
|
| 104 |
|
|
error:
|
| 105 |
|
|
return ret;
|
| 106 |
|
|
|
| 107 |
|
|
} /* end alloc_uid_keyring() */
|
| 108 |
|
|
|
| 109 |
|
|
/*****************************************************************************/
|
| 110 |
|
|
/*
|
| 111 |
|
|
* deal with the UID changing
|
| 112 |
|
|
*/
|
| 113 |
|
|
void switch_uid_keyring(struct user_struct *new_user)
|
| 114 |
|
|
{
|
| 115 |
|
|
#if 0 /* do nothing for now */
|
| 116 |
|
|
struct key *old;
|
| 117 |
|
|
|
| 118 |
|
|
/* switch to the new user's session keyring if we were running under
|
| 119 |
|
|
* root's default session keyring */
|
| 120 |
|
|
if (new_user->uid != 0 &&
|
| 121 |
|
|
current->session_keyring == &root_session_keyring
|
| 122 |
|
|
) {
|
| 123 |
|
|
atomic_inc(&new_user->session_keyring->usage);
|
| 124 |
|
|
|
| 125 |
|
|
task_lock(current);
|
| 126 |
|
|
old = current->session_keyring;
|
| 127 |
|
|
current->session_keyring = new_user->session_keyring;
|
| 128 |
|
|
task_unlock(current);
|
| 129 |
|
|
|
| 130 |
|
|
key_put(old);
|
| 131 |
|
|
}
|
| 132 |
|
|
#endif
|
| 133 |
|
|
|
| 134 |
|
|
} /* end switch_uid_keyring() */
|
| 135 |
|
|
|
| 136 |
|
|
/*****************************************************************************/
|
| 137 |
|
|
/*
|
| 138 |
|
|
* install a fresh thread keyring, discarding the old one
|
| 139 |
|
|
*/
|
| 140 |
|
|
int install_thread_keyring(struct task_struct *tsk)
|
| 141 |
|
|
{
|
| 142 |
|
|
struct key *keyring, *old;
|
| 143 |
|
|
char buf[20];
|
| 144 |
|
|
int ret;
|
| 145 |
|
|
|
| 146 |
|
|
sprintf(buf, "_tid.%u", tsk->pid);
|
| 147 |
|
|
|
| 148 |
|
|
keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
|
| 149 |
|
|
KEY_ALLOC_QUOTA_OVERRUN, NULL);
|
| 150 |
|
|
if (IS_ERR(keyring)) {
|
| 151 |
|
|
ret = PTR_ERR(keyring);
|
| 152 |
|
|
goto error;
|
| 153 |
|
|
}
|
| 154 |
|
|
|
| 155 |
|
|
task_lock(tsk);
|
| 156 |
|
|
old = tsk->thread_keyring;
|
| 157 |
|
|
tsk->thread_keyring = keyring;
|
| 158 |
|
|
task_unlock(tsk);
|
| 159 |
|
|
|
| 160 |
|
|
ret = 0;
|
| 161 |
|
|
|
| 162 |
|
|
key_put(old);
|
| 163 |
|
|
error:
|
| 164 |
|
|
return ret;
|
| 165 |
|
|
|
| 166 |
|
|
} /* end install_thread_keyring() */
|
| 167 |
|
|
|
| 168 |
|
|
/*****************************************************************************/
|
| 169 |
|
|
/*
|
| 170 |
|
|
* make sure a process keyring is installed
|
| 171 |
|
|
*/
|
| 172 |
|
|
int install_process_keyring(struct task_struct *tsk)
|
| 173 |
|
|
{
|
| 174 |
|
|
struct key *keyring;
|
| 175 |
|
|
char buf[20];
|
| 176 |
|
|
int ret;
|
| 177 |
|
|
|
| 178 |
|
|
might_sleep();
|
| 179 |
|
|
|
| 180 |
|
|
if (!tsk->signal->process_keyring) {
|
| 181 |
|
|
sprintf(buf, "_pid.%u", tsk->tgid);
|
| 182 |
|
|
|
| 183 |
|
|
keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
|
| 184 |
|
|
KEY_ALLOC_QUOTA_OVERRUN, NULL);
|
| 185 |
|
|
if (IS_ERR(keyring)) {
|
| 186 |
|
|
ret = PTR_ERR(keyring);
|
| 187 |
|
|
goto error;
|
| 188 |
|
|
}
|
| 189 |
|
|
|
| 190 |
|
|
/* attach keyring */
|
| 191 |
|
|
spin_lock_irq(&tsk->sighand->siglock);
|
| 192 |
|
|
if (!tsk->signal->process_keyring) {
|
| 193 |
|
|
tsk->signal->process_keyring = keyring;
|
| 194 |
|
|
keyring = NULL;
|
| 195 |
|
|
}
|
| 196 |
|
|
spin_unlock_irq(&tsk->sighand->siglock);
|
| 197 |
|
|
|
| 198 |
|
|
key_put(keyring);
|
| 199 |
|
|
}
|
| 200 |
|
|
|
| 201 |
|
|
ret = 0;
|
| 202 |
|
|
error:
|
| 203 |
|
|
return ret;
|
| 204 |
|
|
|
| 205 |
|
|
} /* end install_process_keyring() */
|
| 206 |
|
|
|
| 207 |
|
|
/*****************************************************************************/
|
| 208 |
|
|
/*
|
| 209 |
|
|
* install a session keyring, discarding the old one
|
| 210 |
|
|
* - if a keyring is not supplied, an empty one is invented
|
| 211 |
|
|
*/
|
| 212 |
|
|
static int install_session_keyring(struct task_struct *tsk,
|
| 213 |
|
|
struct key *keyring)
|
| 214 |
|
|
{
|
| 215 |
|
|
unsigned long flags;
|
| 216 |
|
|
struct key *old;
|
| 217 |
|
|
char buf[20];
|
| 218 |
|
|
|
| 219 |
|
|
might_sleep();
|
| 220 |
|
|
|
| 221 |
|
|
/* create an empty session keyring */
|
| 222 |
|
|
if (!keyring) {
|
| 223 |
|
|
sprintf(buf, "_ses.%u", tsk->tgid);
|
| 224 |
|
|
|
| 225 |
|
|
flags = KEY_ALLOC_QUOTA_OVERRUN;
|
| 226 |
|
|
if (tsk->signal->session_keyring)
|
| 227 |
|
|
flags = KEY_ALLOC_IN_QUOTA;
|
| 228 |
|
|
|
| 229 |
|
|
keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
|
| 230 |
|
|
flags, NULL);
|
| 231 |
|
|
if (IS_ERR(keyring))
|
| 232 |
|
|
return PTR_ERR(keyring);
|
| 233 |
|
|
}
|
| 234 |
|
|
else {
|
| 235 |
|
|
atomic_inc(&keyring->usage);
|
| 236 |
|
|
}
|
| 237 |
|
|
|
| 238 |
|
|
/* install the keyring */
|
| 239 |
|
|
spin_lock_irq(&tsk->sighand->siglock);
|
| 240 |
|
|
old = tsk->signal->session_keyring;
|
| 241 |
|
|
rcu_assign_pointer(tsk->signal->session_keyring, keyring);
|
| 242 |
|
|
spin_unlock_irq(&tsk->sighand->siglock);
|
| 243 |
|
|
|
| 244 |
|
|
/* we're using RCU on the pointer, but there's no point synchronising
|
| 245 |
|
|
* on it if it didn't previously point to anything */
|
| 246 |
|
|
if (old) {
|
| 247 |
|
|
synchronize_rcu();
|
| 248 |
|
|
key_put(old);
|
| 249 |
|
|
}
|
| 250 |
|
|
|
| 251 |
|
|
return 0;
|
| 252 |
|
|
|
| 253 |
|
|
} /* end install_session_keyring() */
|
| 254 |
|
|
|
| 255 |
|
|
/*****************************************************************************/
|
| 256 |
|
|
/*
|
| 257 |
|
|
* copy the keys in a thread group for fork without CLONE_THREAD
|
| 258 |
|
|
*/
|
| 259 |
|
|
int copy_thread_group_keys(struct task_struct *tsk)
|
| 260 |
|
|
{
|
| 261 |
|
|
key_check(current->thread_group->session_keyring);
|
| 262 |
|
|
key_check(current->thread_group->process_keyring);
|
| 263 |
|
|
|
| 264 |
|
|
/* no process keyring yet */
|
| 265 |
|
|
tsk->signal->process_keyring = NULL;
|
| 266 |
|
|
|
| 267 |
|
|
/* same session keyring */
|
| 268 |
|
|
rcu_read_lock();
|
| 269 |
|
|
tsk->signal->session_keyring =
|
| 270 |
|
|
key_get(rcu_dereference(current->signal->session_keyring));
|
| 271 |
|
|
rcu_read_unlock();
|
| 272 |
|
|
|
| 273 |
|
|
return 0;
|
| 274 |
|
|
|
| 275 |
|
|
} /* end copy_thread_group_keys() */
|
| 276 |
|
|
|
| 277 |
|
|
/*****************************************************************************/
|
| 278 |
|
|
/*
|
| 279 |
|
|
* copy the keys for fork
|
| 280 |
|
|
*/
|
| 281 |
|
|
int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
|
| 282 |
|
|
{
|
| 283 |
|
|
key_check(tsk->thread_keyring);
|
| 284 |
|
|
key_check(tsk->request_key_auth);
|
| 285 |
|
|
|
| 286 |
|
|
/* no thread keyring yet */
|
| 287 |
|
|
tsk->thread_keyring = NULL;
|
| 288 |
|
|
|
| 289 |
|
|
/* copy the request_key() authorisation for this thread */
|
| 290 |
|
|
key_get(tsk->request_key_auth);
|
| 291 |
|
|
|
| 292 |
|
|
return 0;
|
| 293 |
|
|
|
| 294 |
|
|
} /* end copy_keys() */
|
| 295 |
|
|
|
| 296 |
|
|
/*****************************************************************************/
|
| 297 |
|
|
/*
|
| 298 |
|
|
* dispose of thread group keys upon thread group destruction
|
| 299 |
|
|
*/
|
| 300 |
|
|
void exit_thread_group_keys(struct signal_struct *tg)
|
| 301 |
|
|
{
|
| 302 |
|
|
key_put(tg->session_keyring);
|
| 303 |
|
|
key_put(tg->process_keyring);
|
| 304 |
|
|
|
| 305 |
|
|
} /* end exit_thread_group_keys() */
|
| 306 |
|
|
|
| 307 |
|
|
/*****************************************************************************/
|
| 308 |
|
|
/*
|
| 309 |
|
|
* dispose of per-thread keys upon thread exit
|
| 310 |
|
|
*/
|
| 311 |
|
|
void exit_keys(struct task_struct *tsk)
|
| 312 |
|
|
{
|
| 313 |
|
|
key_put(tsk->thread_keyring);
|
| 314 |
|
|
key_put(tsk->request_key_auth);
|
| 315 |
|
|
|
| 316 |
|
|
} /* end exit_keys() */
|
| 317 |
|
|
|
| 318 |
|
|
/*****************************************************************************/
|
| 319 |
|
|
/*
|
| 320 |
|
|
* deal with execve()
|
| 321 |
|
|
*/
|
| 322 |
|
|
int exec_keys(struct task_struct *tsk)
|
| 323 |
|
|
{
|
| 324 |
|
|
struct key *old;
|
| 325 |
|
|
|
| 326 |
|
|
/* newly exec'd tasks don't get a thread keyring */
|
| 327 |
|
|
task_lock(tsk);
|
| 328 |
|
|
old = tsk->thread_keyring;
|
| 329 |
|
|
tsk->thread_keyring = NULL;
|
| 330 |
|
|
task_unlock(tsk);
|
| 331 |
|
|
|
| 332 |
|
|
key_put(old);
|
| 333 |
|
|
|
| 334 |
|
|
/* discard the process keyring from a newly exec'd task */
|
| 335 |
|
|
spin_lock_irq(&tsk->sighand->siglock);
|
| 336 |
|
|
old = tsk->signal->process_keyring;
|
| 337 |
|
|
tsk->signal->process_keyring = NULL;
|
| 338 |
|
|
spin_unlock_irq(&tsk->sighand->siglock);
|
| 339 |
|
|
|
| 340 |
|
|
key_put(old);
|
| 341 |
|
|
|
| 342 |
|
|
return 0;
|
| 343 |
|
|
|
| 344 |
|
|
} /* end exec_keys() */
|
| 345 |
|
|
|
| 346 |
|
|
/*****************************************************************************/
|
| 347 |
|
|
/*
|
| 348 |
|
|
* deal with SUID programs
|
| 349 |
|
|
* - we might want to make this invent a new session keyring
|
| 350 |
|
|
*/
|
| 351 |
|
|
int suid_keys(struct task_struct *tsk)
|
| 352 |
|
|
{
|
| 353 |
|
|
return 0;
|
| 354 |
|
|
|
| 355 |
|
|
} /* end suid_keys() */
|
| 356 |
|
|
|
| 357 |
|
|
/*****************************************************************************/
|
| 358 |
|
|
/*
|
| 359 |
|
|
* the filesystem user ID changed
|
| 360 |
|
|
*/
|
| 361 |
|
|
void key_fsuid_changed(struct task_struct *tsk)
|
| 362 |
|
|
{
|
| 363 |
|
|
/* update the ownership of the thread keyring */
|
| 364 |
|
|
if (tsk->thread_keyring) {
|
| 365 |
|
|
down_write(&tsk->thread_keyring->sem);
|
| 366 |
|
|
tsk->thread_keyring->uid = tsk->fsuid;
|
| 367 |
|
|
up_write(&tsk->thread_keyring->sem);
|
| 368 |
|
|
}
|
| 369 |
|
|
|
| 370 |
|
|
} /* end key_fsuid_changed() */
|
| 371 |
|
|
|
| 372 |
|
|
/*****************************************************************************/
|
| 373 |
|
|
/*
|
| 374 |
|
|
* the filesystem group ID changed
|
| 375 |
|
|
*/
|
| 376 |
|
|
void key_fsgid_changed(struct task_struct *tsk)
|
| 377 |
|
|
{
|
| 378 |
|
|
/* update the ownership of the thread keyring */
|
| 379 |
|
|
if (tsk->thread_keyring) {
|
| 380 |
|
|
down_write(&tsk->thread_keyring->sem);
|
| 381 |
|
|
tsk->thread_keyring->gid = tsk->fsgid;
|
| 382 |
|
|
up_write(&tsk->thread_keyring->sem);
|
| 383 |
|
|
}
|
| 384 |
|
|
|
| 385 |
|
|
} /* end key_fsgid_changed() */
|
| 386 |
|
|
|
| 387 |
|
|
/*****************************************************************************/
|
| 388 |
|
|
/*
|
| 389 |
|
|
* search the process keyrings for the first matching key
|
| 390 |
|
|
* - we use the supplied match function to see if the description (or other
|
| 391 |
|
|
* feature of interest) matches
|
| 392 |
|
|
* - we return -EAGAIN if we didn't find any matching key
|
| 393 |
|
|
* - we return -ENOKEY if we found only negative matching keys
|
| 394 |
|
|
*/
|
| 395 |
|
|
key_ref_t search_process_keyrings(struct key_type *type,
|
| 396 |
|
|
const void *description,
|
| 397 |
|
|
key_match_func_t match,
|
| 398 |
|
|
struct task_struct *context)
|
| 399 |
|
|
{
|
| 400 |
|
|
struct request_key_auth *rka;
|
| 401 |
|
|
key_ref_t key_ref, ret, err;
|
| 402 |
|
|
|
| 403 |
|
|
might_sleep();
|
| 404 |
|
|
|
| 405 |
|
|
/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
|
| 406 |
|
|
* searchable, but we failed to find a key or we found a negative key;
|
| 407 |
|
|
* otherwise we want to return a sample error (probably -EACCES) if
|
| 408 |
|
|
* none of the keyrings were searchable
|
| 409 |
|
|
*
|
| 410 |
|
|
* in terms of priority: success > -ENOKEY > -EAGAIN > other error
|
| 411 |
|
|
*/
|
| 412 |
|
|
key_ref = NULL;
|
| 413 |
|
|
ret = NULL;
|
| 414 |
|
|
err = ERR_PTR(-EAGAIN);
|
| 415 |
|
|
|
| 416 |
|
|
/* search the thread keyring first */
|
| 417 |
|
|
if (context->thread_keyring) {
|
| 418 |
|
|
key_ref = keyring_search_aux(
|
| 419 |
|
|
make_key_ref(context->thread_keyring, 1),
|
| 420 |
|
|
context, type, description, match);
|
| 421 |
|
|
if (!IS_ERR(key_ref))
|
| 422 |
|
|
goto found;
|
| 423 |
|
|
|
| 424 |
|
|
switch (PTR_ERR(key_ref)) {
|
| 425 |
|
|
case -EAGAIN: /* no key */
|
| 426 |
|
|
if (ret)
|
| 427 |
|
|
break;
|
| 428 |
|
|
case -ENOKEY: /* negative key */
|
| 429 |
|
|
ret = key_ref;
|
| 430 |
|
|
break;
|
| 431 |
|
|
default:
|
| 432 |
|
|
err = key_ref;
|
| 433 |
|
|
break;
|
| 434 |
|
|
}
|
| 435 |
|
|
}
|
| 436 |
|
|
|
| 437 |
|
|
/* search the process keyring second */
|
| 438 |
|
|
if (context->signal->process_keyring) {
|
| 439 |
|
|
key_ref = keyring_search_aux(
|
| 440 |
|
|
make_key_ref(context->signal->process_keyring, 1),
|
| 441 |
|
|
context, type, description, match);
|
| 442 |
|
|
if (!IS_ERR(key_ref))
|
| 443 |
|
|
goto found;
|
| 444 |
|
|
|
| 445 |
|
|
switch (PTR_ERR(key_ref)) {
|
| 446 |
|
|
case -EAGAIN: /* no key */
|
| 447 |
|
|
if (ret)
|
| 448 |
|
|
break;
|
| 449 |
|
|
case -ENOKEY: /* negative key */
|
| 450 |
|
|
ret = key_ref;
|
| 451 |
|
|
break;
|
| 452 |
|
|
default:
|
| 453 |
|
|
err = key_ref;
|
| 454 |
|
|
break;
|
| 455 |
|
|
}
|
| 456 |
|
|
}
|
| 457 |
|
|
|
| 458 |
|
|
/* search the session keyring */
|
| 459 |
|
|
if (context->signal->session_keyring) {
|
| 460 |
|
|
rcu_read_lock();
|
| 461 |
|
|
key_ref = keyring_search_aux(
|
| 462 |
|
|
make_key_ref(rcu_dereference(
|
| 463 |
|
|
context->signal->session_keyring),
|
| 464 |
|
|
1),
|
| 465 |
|
|
context, type, description, match);
|
| 466 |
|
|
rcu_read_unlock();
|
| 467 |
|
|
|
| 468 |
|
|
if (!IS_ERR(key_ref))
|
| 469 |
|
|
goto found;
|
| 470 |
|
|
|
| 471 |
|
|
switch (PTR_ERR(key_ref)) {
|
| 472 |
|
|
case -EAGAIN: /* no key */
|
| 473 |
|
|
if (ret)
|
| 474 |
|
|
break;
|
| 475 |
|
|
case -ENOKEY: /* negative key */
|
| 476 |
|
|
ret = key_ref;
|
| 477 |
|
|
break;
|
| 478 |
|
|
default:
|
| 479 |
|
|
err = key_ref;
|
| 480 |
|
|
break;
|
| 481 |
|
|
}
|
| 482 |
|
|
}
|
| 483 |
|
|
/* or search the user-session keyring */
|
| 484 |
|
|
else {
|
| 485 |
|
|
key_ref = keyring_search_aux(
|
| 486 |
|
|
make_key_ref(context->user->session_keyring, 1),
|
| 487 |
|
|
context, type, description, match);
|
| 488 |
|
|
if (!IS_ERR(key_ref))
|
| 489 |
|
|
goto found;
|
| 490 |
|
|
|
| 491 |
|
|
switch (PTR_ERR(key_ref)) {
|
| 492 |
|
|
case -EAGAIN: /* no key */
|
| 493 |
|
|
if (ret)
|
| 494 |
|
|
break;
|
| 495 |
|
|
case -ENOKEY: /* negative key */
|
| 496 |
|
|
ret = key_ref;
|
| 497 |
|
|
break;
|
| 498 |
|
|
default:
|
| 499 |
|
|
err = key_ref;
|
| 500 |
|
|
break;
|
| 501 |
|
|
}
|
| 502 |
|
|
}
|
| 503 |
|
|
|
| 504 |
|
|
/* if this process has an instantiation authorisation key, then we also
|
| 505 |
|
|
* search the keyrings of the process mentioned there
|
| 506 |
|
|
* - we don't permit access to request_key auth keys via this method
|
| 507 |
|
|
*/
|
| 508 |
|
|
if (context->request_key_auth &&
|
| 509 |
|
|
context == current &&
|
| 510 |
|
|
type != &key_type_request_key_auth
|
| 511 |
|
|
) {
|
| 512 |
|
|
/* defend against the auth key being revoked */
|
| 513 |
|
|
down_read(&context->request_key_auth->sem);
|
| 514 |
|
|
|
| 515 |
|
|
if (key_validate(context->request_key_auth) == 0) {
|
| 516 |
|
|
rka = context->request_key_auth->payload.data;
|
| 517 |
|
|
|
| 518 |
|
|
key_ref = search_process_keyrings(type, description,
|
| 519 |
|
|
match, rka->context);
|
| 520 |
|
|
|
| 521 |
|
|
up_read(&context->request_key_auth->sem);
|
| 522 |
|
|
|
| 523 |
|
|
if (!IS_ERR(key_ref))
|
| 524 |
|
|
goto found;
|
| 525 |
|
|
|
| 526 |
|
|
switch (PTR_ERR(key_ref)) {
|
| 527 |
|
|
case -EAGAIN: /* no key */
|
| 528 |
|
|
if (ret)
|
| 529 |
|
|
break;
|
| 530 |
|
|
case -ENOKEY: /* negative key */
|
| 531 |
|
|
ret = key_ref;
|
| 532 |
|
|
break;
|
| 533 |
|
|
default:
|
| 534 |
|
|
err = key_ref;
|
| 535 |
|
|
break;
|
| 536 |
|
|
}
|
| 537 |
|
|
} else {
|
| 538 |
|
|
up_read(&context->request_key_auth->sem);
|
| 539 |
|
|
}
|
| 540 |
|
|
}
|
| 541 |
|
|
|
| 542 |
|
|
/* no key - decide on the error we're going to go for */
|
| 543 |
|
|
key_ref = ret ? ret : err;
|
| 544 |
|
|
|
| 545 |
|
|
found:
|
| 546 |
|
|
return key_ref;
|
| 547 |
|
|
|
| 548 |
|
|
} /* end search_process_keyrings() */
|
| 549 |
|
|
|
| 550 |
|
|
/*****************************************************************************/
|
| 551 |
|
|
/*
|
| 552 |
|
|
* see if the key we're looking at is the target key
|
| 553 |
|
|
*/
|
| 554 |
|
|
static int lookup_user_key_possessed(const struct key *key, const void *target)
|
| 555 |
|
|
{
|
| 556 |
|
|
return key == target;
|
| 557 |
|
|
|
| 558 |
|
|
} /* end lookup_user_key_possessed() */
|
| 559 |
|
|
|
| 560 |
|
|
/*****************************************************************************/
|
| 561 |
|
|
/*
|
| 562 |
|
|
* lookup a key given a key ID from userspace with a given permissions mask
|
| 563 |
|
|
* - don't create special keyrings unless so requested
|
| 564 |
|
|
* - partially constructed keys aren't found unless requested
|
| 565 |
|
|
*/
|
| 566 |
|
|
key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id,
|
| 567 |
|
|
int create, int partial, key_perm_t perm)
|
| 568 |
|
|
{
|
| 569 |
|
|
key_ref_t key_ref, skey_ref;
|
| 570 |
|
|
struct key *key;
|
| 571 |
|
|
int ret;
|
| 572 |
|
|
|
| 573 |
|
|
if (!context)
|
| 574 |
|
|
context = current;
|
| 575 |
|
|
|
| 576 |
|
|
key_ref = ERR_PTR(-ENOKEY);
|
| 577 |
|
|
|
| 578 |
|
|
switch (id) {
|
| 579 |
|
|
case KEY_SPEC_THREAD_KEYRING:
|
| 580 |
|
|
if (!context->thread_keyring) {
|
| 581 |
|
|
if (!create)
|
| 582 |
|
|
goto error;
|
| 583 |
|
|
|
| 584 |
|
|
ret = install_thread_keyring(context);
|
| 585 |
|
|
if (ret < 0) {
|
| 586 |
|
|
key = ERR_PTR(ret);
|
| 587 |
|
|
goto error;
|
| 588 |
|
|
}
|
| 589 |
|
|
}
|
| 590 |
|
|
|
| 591 |
|
|
key = context->thread_keyring;
|
| 592 |
|
|
atomic_inc(&key->usage);
|
| 593 |
|
|
key_ref = make_key_ref(key, 1);
|
| 594 |
|
|
break;
|
| 595 |
|
|
|
| 596 |
|
|
case KEY_SPEC_PROCESS_KEYRING:
|
| 597 |
|
|
if (!context->signal->process_keyring) {
|
| 598 |
|
|
if (!create)
|
| 599 |
|
|
goto error;
|
| 600 |
|
|
|
| 601 |
|
|
ret = install_process_keyring(context);
|
| 602 |
|
|
if (ret < 0) {
|
| 603 |
|
|
key = ERR_PTR(ret);
|
| 604 |
|
|
goto error;
|
| 605 |
|
|
}
|
| 606 |
|
|
}
|
| 607 |
|
|
|
| 608 |
|
|
key = context->signal->process_keyring;
|
| 609 |
|
|
atomic_inc(&key->usage);
|
| 610 |
|
|
key_ref = make_key_ref(key, 1);
|
| 611 |
|
|
break;
|
| 612 |
|
|
|
| 613 |
|
|
case KEY_SPEC_SESSION_KEYRING:
|
| 614 |
|
|
if (!context->signal->session_keyring) {
|
| 615 |
|
|
/* always install a session keyring upon access if one
|
| 616 |
|
|
* doesn't exist yet */
|
| 617 |
|
|
ret = install_session_keyring(
|
| 618 |
|
|
context, context->user->session_keyring);
|
| 619 |
|
|
if (ret < 0)
|
| 620 |
|
|
goto error;
|
| 621 |
|
|
}
|
| 622 |
|
|
|
| 623 |
|
|
rcu_read_lock();
|
| 624 |
|
|
key = rcu_dereference(context->signal->session_keyring);
|
| 625 |
|
|
atomic_inc(&key->usage);
|
| 626 |
|
|
rcu_read_unlock();
|
| 627 |
|
|
key_ref = make_key_ref(key, 1);
|
| 628 |
|
|
break;
|
| 629 |
|
|
|
| 630 |
|
|
case KEY_SPEC_USER_KEYRING:
|
| 631 |
|
|
key = context->user->uid_keyring;
|
| 632 |
|
|
atomic_inc(&key->usage);
|
| 633 |
|
|
key_ref = make_key_ref(key, 1);
|
| 634 |
|
|
break;
|
| 635 |
|
|
|
| 636 |
|
|
case KEY_SPEC_USER_SESSION_KEYRING:
|
| 637 |
|
|
key = context->user->session_keyring;
|
| 638 |
|
|
atomic_inc(&key->usage);
|
| 639 |
|
|
key_ref = make_key_ref(key, 1);
|
| 640 |
|
|
break;
|
| 641 |
|
|
|
| 642 |
|
|
case KEY_SPEC_GROUP_KEYRING:
|
| 643 |
|
|
/* group keyrings are not yet supported */
|
| 644 |
|
|
key = ERR_PTR(-EINVAL);
|
| 645 |
|
|
goto error;
|
| 646 |
|
|
|
| 647 |
|
|
case KEY_SPEC_REQKEY_AUTH_KEY:
|
| 648 |
|
|
key = context->request_key_auth;
|
| 649 |
|
|
if (!key)
|
| 650 |
|
|
goto error;
|
| 651 |
|
|
|
| 652 |
|
|
atomic_inc(&key->usage);
|
| 653 |
|
|
key_ref = make_key_ref(key, 1);
|
| 654 |
|
|
break;
|
| 655 |
|
|
|
| 656 |
|
|
default:
|
| 657 |
|
|
key_ref = ERR_PTR(-EINVAL);
|
| 658 |
|
|
if (id < 1)
|
| 659 |
|
|
goto error;
|
| 660 |
|
|
|
| 661 |
|
|
key = key_lookup(id);
|
| 662 |
|
|
if (IS_ERR(key)) {
|
| 663 |
|
|
key_ref = ERR_PTR(PTR_ERR(key));
|
| 664 |
|
|
goto error;
|
| 665 |
|
|
}
|
| 666 |
|
|
|
| 667 |
|
|
key_ref = make_key_ref(key, 0);
|
| 668 |
|
|
|
| 669 |
|
|
/* check to see if we possess the key */
|
| 670 |
|
|
skey_ref = search_process_keyrings(key->type, key,
|
| 671 |
|
|
lookup_user_key_possessed,
|
| 672 |
|
|
current);
|
| 673 |
|
|
|
| 674 |
|
|
if (!IS_ERR(skey_ref)) {
|
| 675 |
|
|
key_put(key);
|
| 676 |
|
|
key_ref = skey_ref;
|
| 677 |
|
|
}
|
| 678 |
|
|
|
| 679 |
|
|
break;
|
| 680 |
|
|
}
|
| 681 |
|
|
|
| 682 |
|
|
if (!partial) {
|
| 683 |
|
|
ret = wait_for_key_construction(key, true);
|
| 684 |
|
|
switch (ret) {
|
| 685 |
|
|
case -ERESTARTSYS:
|
| 686 |
|
|
goto invalid_key;
|
| 687 |
|
|
default:
|
| 688 |
|
|
if (perm)
|
| 689 |
|
|
goto invalid_key;
|
| 690 |
|
|
case 0:
|
| 691 |
|
|
break;
|
| 692 |
|
|
}
|
| 693 |
|
|
} else if (perm) {
|
| 694 |
|
|
ret = key_validate(key);
|
| 695 |
|
|
if (ret < 0)
|
| 696 |
|
|
goto invalid_key;
|
| 697 |
|
|
}
|
| 698 |
|
|
|
| 699 |
|
|
ret = -EIO;
|
| 700 |
|
|
if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
|
| 701 |
|
|
goto invalid_key;
|
| 702 |
|
|
|
| 703 |
|
|
/* check the permissions */
|
| 704 |
|
|
ret = key_task_permission(key_ref, context, perm);
|
| 705 |
|
|
if (ret < 0)
|
| 706 |
|
|
goto invalid_key;
|
| 707 |
|
|
|
| 708 |
|
|
error:
|
| 709 |
|
|
return key_ref;
|
| 710 |
|
|
|
| 711 |
|
|
invalid_key:
|
| 712 |
|
|
key_ref_put(key_ref);
|
| 713 |
|
|
key_ref = ERR_PTR(ret);
|
| 714 |
|
|
goto error;
|
| 715 |
|
|
|
| 716 |
|
|
} /* end lookup_user_key() */
|
| 717 |
|
|
|
| 718 |
|
|
/*****************************************************************************/
|
| 719 |
|
|
/*
|
| 720 |
|
|
* join the named keyring as the session keyring if possible, or attempt to
|
| 721 |
|
|
* create a new one of that name if not
|
| 722 |
|
|
* - if the name is NULL, an empty anonymous keyring is installed instead
|
| 723 |
|
|
* - named session keyring joining is done with a semaphore held
|
| 724 |
|
|
*/
|
| 725 |
|
|
long join_session_keyring(const char *name)
|
| 726 |
|
|
{
|
| 727 |
|
|
struct task_struct *tsk = current;
|
| 728 |
|
|
struct key *keyring;
|
| 729 |
|
|
long ret;
|
| 730 |
|
|
|
| 731 |
|
|
/* if no name is provided, install an anonymous keyring */
|
| 732 |
|
|
if (!name) {
|
| 733 |
|
|
ret = install_session_keyring(tsk, NULL);
|
| 734 |
|
|
if (ret < 0)
|
| 735 |
|
|
goto error;
|
| 736 |
|
|
|
| 737 |
|
|
rcu_read_lock();
|
| 738 |
|
|
ret = rcu_dereference(tsk->signal->session_keyring)->serial;
|
| 739 |
|
|
rcu_read_unlock();
|
| 740 |
|
|
goto error;
|
| 741 |
|
|
}
|
| 742 |
|
|
|
| 743 |
|
|
/* allow the user to join or create a named keyring */
|
| 744 |
|
|
mutex_lock(&key_session_mutex);
|
| 745 |
|
|
|
| 746 |
|
|
/* look for an existing keyring of this name */
|
| 747 |
|
|
keyring = find_keyring_by_name(name, 0);
|
| 748 |
|
|
if (PTR_ERR(keyring) == -ENOKEY) {
|
| 749 |
|
|
/* not found - try and create a new one */
|
| 750 |
|
|
keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk,
|
| 751 |
|
|
KEY_ALLOC_IN_QUOTA, NULL);
|
| 752 |
|
|
if (IS_ERR(keyring)) {
|
| 753 |
|
|
ret = PTR_ERR(keyring);
|
| 754 |
|
|
goto error2;
|
| 755 |
|
|
}
|
| 756 |
|
|
}
|
| 757 |
|
|
else if (IS_ERR(keyring)) {
|
| 758 |
|
|
ret = PTR_ERR(keyring);
|
| 759 |
|
|
goto error2;
|
| 760 |
|
|
}
|
| 761 |
|
|
|
| 762 |
|
|
/* we've got a keyring - now to install it */
|
| 763 |
|
|
ret = install_session_keyring(tsk, keyring);
|
| 764 |
|
|
if (ret < 0)
|
| 765 |
|
|
goto error2;
|
| 766 |
|
|
|
| 767 |
|
|
ret = keyring->serial;
|
| 768 |
|
|
key_put(keyring);
|
| 769 |
|
|
|
| 770 |
|
|
error2:
|
| 771 |
|
|
mutex_unlock(&key_session_mutex);
|
| 772 |
|
|
error:
|
| 773 |
|
|
return ret;
|
| 774 |
|
|
|
| 775 |
|
|
} /* end join_session_keyring() */
|
