| Message ID | 20190103143227.9138-3-jlee@suse.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | Encryption and authentication for hibernate snapshot image | expand |
Am Donnerstag, 3. Januar 2019, 15:32:24 CET schrieb Lee, Chun-Yi: Hi Chun, > +int snapshot_image_verify_decrypt(void) > +{ > + int ret, i; > + > + if (!h_buf) { > + ret = -ENOMEM; > + goto error; > + } > + > + ret = snapshot_key_init(); > + if (ret) > + goto error_prep; > + > + ret = snapshot_prepare_hash(true); > + if (ret || !s4_verify_desc) > + goto error_prep; > + > + for (i = 0; i < nr_copy_pages; i++) { > + ret = crypto_shash_update(s4_verify_desc, *(h_buf + i), PAGE_SIZE); > + if (ret) > + goto error_shash; > + } > + > + ret = crypto_shash_final(s4_verify_desc, s4_verify_digest); > + if (ret) > + goto error_shash; > + > + pr_debug("Signature %*phN\n", SNAPSHOT_DIGEST_SIZE, signature); > + pr_debug("Digest %*phN\n", SNAPSHOT_DIGEST_SIZE, s4_verify_digest); > + if (memcmp(signature, s4_verify_digest, SNAPSHOT_DIGEST_SIZE)) > + ret = -EKEYREJECTED; > + > + error_shash: > + snapshot_finish_hash(); > + > + error_prep: > + vfree(h_buf); > + if (ret) > + pr_warn("Signature verification failed: %d\n", ret); > + error: > + sig_verify_ret = ret; > + return ret; > +} May I ask why the authentication part is done manually here? Why not using an AEAD cipher like the authenc() ciphers, or CCM (I would not recommend GCM though)? In this case, the encryption/decryption operation would automatically perform the creation of the hash and the verification of the hash. I.e. decryption can return EBADMSG which indicates an authentication failure. > + > +static int > +__copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap > *orig_bm) +{ > + unsigned long pfn, dst_pfn; > + struct page *d_page; > + void *crypto_buffer = NULL; > + int ret = 0; > + > + memory_bm_position_reset(orig_bm); > + memory_bm_position_reset(copy_bm); > + for (;;) { > + pfn = memory_bm_next_pfn(orig_bm); > + if (unlikely(pfn == BM_END_OF_MAP)) > + break; > + dst_pfn = memory_bm_next_pfn(copy_bm); > + copy_data_page(dst_pfn, pfn); > + > + /* Setup buffer */ > + d_page = pfn_to_page(dst_pfn); > + if (PageHighMem(d_page)) { > + void *kaddr = kmap_atomic(d_page); > + > + copy_page(buffer, kaddr); > + kunmap_atomic(kaddr); > + crypto_buffer = buffer; > + } else { > + crypto_buffer = page_address(d_page); > + } > + > + /* Generate digest */ > + if (!s4_verify_desc) > + continue; > + ret = crypto_shash_update(s4_verify_desc, crypto_buffer, > + PAGE_SIZE); Same here, the creation of the hash would be implicit during the encryption. Ciao Stephan
Hi Chun-Yi,
url: https://github.com/0day-ci/linux/commits/Lee-Chun-Yi/Encryption-and-authentication-for-hibernate-snapshot-image/20190104-062004
smatch warnings:
kernel/power/user.c:411 snapshot_ioctl() warn: inconsistent returns 'mutex:&system_transition_mutex'.
Locked on: line 265
Unlocked on: line 213
[ There are some returns missing. I don't know how/why... -dan ]
# https://github.com/0day-ci/linux/commit/1e583ff7a095d508d78bea4d35a916594c2fc23c
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 1e583ff7a095d508d78bea4d35a916594c2fc23c
vim +411 kernel/power/user.c
6e1819d61 Rafael J. Wysocki 2006-03-23 203
52d11025d Alan Cox 2008-06-11 204 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025d Alan Cox 2008-06-11 205 unsigned long arg)
6e1819d61 Rafael J. Wysocki 2006-03-23 206 {
6e1819d61 Rafael J. Wysocki 2006-03-23 207 int error = 0;
6e1819d61 Rafael J. Wysocki 2006-03-23 208 struct snapshot_data *data;
af508b34d Rafael J. Wysocki 2007-10-26 209 loff_t size;
3aef83e0e Rafael J. Wysocki 2006-12-06 210 sector_t offset;
6e1819d61 Rafael J. Wysocki 2006-03-23 211
6e1819d61 Rafael J. Wysocki 2006-03-23 212 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
6e1819d61 Rafael J. Wysocki 2006-03-23 213 return -ENOTTY;
6e1819d61 Rafael J. Wysocki 2006-03-23 214 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
6e1819d61 Rafael J. Wysocki 2006-03-23 215 return -ENOTTY;
6e1819d61 Rafael J. Wysocki 2006-03-23 216 if (!capable(CAP_SYS_ADMIN))
6e1819d61 Rafael J. Wysocki 2006-03-23 217 return -EPERM;
6e1819d61 Rafael J. Wysocki 2006-03-23 218
55f2503c3 Pingfan Liu 2018-07-31 219 if (!mutex_trylock(&system_transition_mutex))
25f2f3daa Rafael J. Wysocki 2008-06-11 220 return -EBUSY;
6e1819d61 Rafael J. Wysocki 2006-03-23 221
942f40155 Rafael J. Wysocki 2013-08-30 222 lock_device_hotplug();
25f2f3daa Rafael J. Wysocki 2008-06-11 223 data = filp->private_data;
52d11025d Alan Cox 2008-06-11 224
6e1819d61 Rafael J. Wysocki 2006-03-23 225 switch (cmd) {
6e1819d61 Rafael J. Wysocki 2006-03-23 226
6e1819d61 Rafael J. Wysocki 2006-03-23 227 case SNAPSHOT_FREEZE:
6e1819d61 Rafael J. Wysocki 2006-03-23 228 if (data->frozen)
6e1819d61 Rafael J. Wysocki 2006-03-23 229 break;
1bfcf1304 Rafael J. Wysocki 2008-10-15 230
232b14328 Rafael J. Wysocki 2007-10-18 231 printk("Syncing filesystems ... ");
70f68ee81 Dominik Brodowski 2018-03-14 232 ksys_sync();
232b14328 Rafael J. Wysocki 2007-10-18 233 printk("done.\n");
232b14328 Rafael J. Wysocki 2007-10-18 234
1bfcf1304 Rafael J. Wysocki 2008-10-15 235 error = freeze_processes();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 236 if (error)
8fd37a4c9 Rafael J. Wysocki 2013-08-30 237 break;
8fd37a4c9 Rafael J. Wysocki 2013-08-30 238
8fd37a4c9 Rafael J. Wysocki 2013-08-30 239 error = create_basic_memory_bitmaps();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 240 if (error)
8fd37a4c9 Rafael J. Wysocki 2013-08-30 241 thaw_processes();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 242 else
7bc9b1cff Rafael J. Wysocki 2013-10-18 243 data->frozen = true;
8fd37a4c9 Rafael J. Wysocki 2013-08-30 244
6e1819d61 Rafael J. Wysocki 2006-03-23 245 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 246
6e1819d61 Rafael J. Wysocki 2006-03-23 247 case SNAPSHOT_UNFREEZE:
2f41dddbb Rafael J. Wysocki 2007-06-16 248 if (!data->frozen || data->ready)
6e1819d61 Rafael J. Wysocki 2006-03-23 249 break;
c9e664f1f Rafael J. Wysocki 2010-12-03 250 pm_restore_gfp_mask();
1e583ff7a Lee, Chun-Yi 2019-01-03 251 snapshot_restore_trampoline();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 252 free_basic_memory_bitmaps();
aab172891 Rafael J. Wysocki 2013-09-30 253 data->free_bitmaps = false;
6e1819d61 Rafael J. Wysocki 2006-03-23 254 thaw_processes();
7bc9b1cff Rafael J. Wysocki 2013-10-18 255 data->frozen = false;
6e1819d61 Rafael J. Wysocki 2006-03-23 256 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 257
b694e52eb Jiri Slaby 2010-01-27 258 case SNAPSHOT_CREATE_IMAGE:
6e1819d61 Rafael J. Wysocki 2006-03-23 259 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
6e1819d61 Rafael J. Wysocki 2006-03-23 260 error = -EPERM;
6e1819d61 Rafael J. Wysocki 2006-03-23 261 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 262 }
1e583ff7a Lee, Chun-Yi 2019-01-03 263 error = snapshot_key_init();
1e583ff7a Lee, Chun-Yi 2019-01-03 264 if (error)
1e583ff7a Lee, Chun-Yi 2019-01-03 265 return error;
^^^^^^^^^^^^^
1e583ff7a Lee, Chun-Yi 2019-01-03 266 error = snapshot_create_trampoline();
1e583ff7a Lee, Chun-Yi 2019-01-03 267 if (error)
1e583ff7a Lee, Chun-Yi 2019-01-03 268 return error;
^^^^^^^^^^^^^
These should be break statements.
c9e664f1f Rafael J. Wysocki 2010-12-03 269 pm_restore_gfp_mask();
eb57c1cf0 Rafael J. Wysocki 2007-10-26 270 error = hibernation_snapshot(data->platform_support);
51d6ff7ac Srivatsa S. Bhat 2012-02-04 271 if (!error) {
cc5d207c8 Rafael J. Wysocki 2007-10-26 272 error = put_user(in_suspend, (int __user *)arg);
a556d5b58 Srivatsa S. Bhat 2012-02-04 273 data->ready = !freezer_test_done && !error;
97819a262 Srivatsa S. Bhat 2011-12-01 274 freezer_test_done = false;
97819a262 Srivatsa S. Bhat 2011-12-01 275 }
6e1819d61 Rafael J. Wysocki 2006-03-23 276 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 277
6e1819d61 Rafael J. Wysocki 2006-03-23 278 case SNAPSHOT_ATOMIC_RESTORE:
8357376d3 Rafael J. Wysocki 2006-12-06 279 snapshot_write_finalize(&data->handle);
6e1819d61 Rafael J. Wysocki 2006-03-23 280 if (data->mode != O_WRONLY || !data->frozen ||
6e1819d61 Rafael J. Wysocki 2006-03-23 281 !snapshot_image_loaded(&data->handle)) {
6e1819d61 Rafael J. Wysocki 2006-03-23 282 error = -EPERM;
6e1819d61 Rafael J. Wysocki 2006-03-23 283 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 284 }
1e583ff7a Lee, Chun-Yi 2019-01-03 285 if (snapshot_image_verify_decrypt()) {
1e583ff7a Lee, Chun-Yi 2019-01-03 286 error = -EPERM;
1e583ff7a Lee, Chun-Yi 2019-01-03 287 break;
1e583ff7a Lee, Chun-Yi 2019-01-03 288 }
1e583ff7a Lee, Chun-Yi 2019-01-03 289 snapshot_init_trampoline();
eb57c1cf0 Rafael J. Wysocki 2007-10-26 290 error = hibernation_restore(data->platform_support);
6e1819d61 Rafael J. Wysocki 2006-03-23 291 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 292
6e1819d61 Rafael J. Wysocki 2006-03-23 293 case SNAPSHOT_FREE:
6e1819d61 Rafael J. Wysocki 2006-03-23 294 swsusp_free();
6e1819d61 Rafael J. Wysocki 2006-03-23 295 memset(&data->handle, 0, sizeof(struct snapshot_handle));
7bc9b1cff Rafael J. Wysocki 2013-10-18 296 data->ready = false;
181e9bdef Rafael J. Wysocki 2012-01-29 297 /*
181e9bdef Rafael J. Wysocki 2012-01-29 298 * It is necessary to thaw kernel threads here, because
181e9bdef Rafael J. Wysocki 2012-01-29 299 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
181e9bdef Rafael J. Wysocki 2012-01-29 300 * SNAPSHOT_FREE. In that case, if kernel threads were not
181e9bdef Rafael J. Wysocki 2012-01-29 301 * thawed, the preallocation of memory carried out by
181e9bdef Rafael J. Wysocki 2012-01-29 302 * hibernation_snapshot() might run into problems (i.e. it
181e9bdef Rafael J. Wysocki 2012-01-29 303 * might fail or even deadlock).
181e9bdef Rafael J. Wysocki 2012-01-29 304 */
181e9bdef Rafael J. Wysocki 2012-01-29 305 thaw_kernel_threads();
6e1819d61 Rafael J. Wysocki 2006-03-23 306 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 307
b694e52eb Jiri Slaby 2010-01-27 308 case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d61 Rafael J. Wysocki 2006-03-23 309 image_size = arg;
6e1819d61 Rafael J. Wysocki 2006-03-23 310 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 311
af508b34d Rafael J. Wysocki 2007-10-26 312 case SNAPSHOT_GET_IMAGE_SIZE:
af508b34d Rafael J. Wysocki 2007-10-26 313 if (!data->ready) {
af508b34d Rafael J. Wysocki 2007-10-26 314 error = -ENODATA;
af508b34d Rafael J. Wysocki 2007-10-26 315 break;
af508b34d Rafael J. Wysocki 2007-10-26 316 }
af508b34d Rafael J. Wysocki 2007-10-26 317 size = snapshot_get_image_size();
af508b34d Rafael J. Wysocki 2007-10-26 318 size <<= PAGE_SHIFT;
af508b34d Rafael J. Wysocki 2007-10-26 319 error = put_user(size, (loff_t __user *)arg);
af508b34d Rafael J. Wysocki 2007-10-26 320 break;
af508b34d Rafael J. Wysocki 2007-10-26 321
b694e52eb Jiri Slaby 2010-01-27 322 case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34d Rafael J. Wysocki 2007-10-26 323 size = count_swap_pages(data->swap, 1);
af508b34d Rafael J. Wysocki 2007-10-26 324 size <<= PAGE_SHIFT;
af508b34d Rafael J. Wysocki 2007-10-26 325 error = put_user(size, (loff_t __user *)arg);
6e1819d61 Rafael J. Wysocki 2006-03-23 326 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 327
b694e52eb Jiri Slaby 2010-01-27 328 case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d61 Rafael J. Wysocki 2006-03-23 329 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
6e1819d61 Rafael J. Wysocki 2006-03-23 330 error = -ENODEV;
6e1819d61 Rafael J. Wysocki 2006-03-23 331 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 332 }
d1d241cc2 Rafael J. Wysocki 2007-05-06 333 offset = alloc_swapdev_block(data->swap);
6e1819d61 Rafael J. Wysocki 2006-03-23 334 if (offset) {
6e1819d61 Rafael J. Wysocki 2006-03-23 335 offset <<= PAGE_SHIFT;
cc5d207c8 Rafael J. Wysocki 2007-10-26 336 error = put_user(offset, (loff_t __user *)arg);
6e1819d61 Rafael J. Wysocki 2006-03-23 337 } else {
6e1819d61 Rafael J. Wysocki 2006-03-23 338 error = -ENOSPC;
6e1819d61 Rafael J. Wysocki 2006-03-23 339 }
6e1819d61 Rafael J. Wysocki 2006-03-23 340 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 341
6e1819d61 Rafael J. Wysocki 2006-03-23 342 case SNAPSHOT_FREE_SWAP_PAGES:
6e1819d61 Rafael J. Wysocki 2006-03-23 343 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
6e1819d61 Rafael J. Wysocki 2006-03-23 344 error = -ENODEV;
6e1819d61 Rafael J. Wysocki 2006-03-23 345 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 346 }
d1d241cc2 Rafael J. Wysocki 2007-05-06 347 free_all_swap_pages(data->swap);
6e1819d61 Rafael J. Wysocki 2006-03-23 348 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 349
9b238205b Luca Tettamanti 2006-03-23 350 case SNAPSHOT_S2RAM:
9b238205b Luca Tettamanti 2006-03-23 351 if (!data->frozen) {
9b238205b Luca Tettamanti 2006-03-23 352 error = -EPERM;
9b238205b Luca Tettamanti 2006-03-23 353 break;
9b238205b Luca Tettamanti 2006-03-23 354 }
6c961dfb7 Rafael J. Wysocki 2007-07-19 355 /*
6c961dfb7 Rafael J. Wysocki 2007-07-19 356 * Tasks are frozen and the notifiers have been called with
6c961dfb7 Rafael J. Wysocki 2007-07-19 357 * PM_HIBERNATION_PREPARE
6c961dfb7 Rafael J. Wysocki 2007-07-19 358 */
6c961dfb7 Rafael J. Wysocki 2007-07-19 359 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
7bc9b1cff Rafael J. Wysocki 2013-10-18 360 data->ready = false;
9b238205b Luca Tettamanti 2006-03-23 361 break;
9b238205b Luca Tettamanti 2006-03-23 362
eb57c1cf0 Rafael J. Wysocki 2007-10-26 363 case SNAPSHOT_PLATFORM_SUPPORT:
eb57c1cf0 Rafael J. Wysocki 2007-10-26 364 data->platform_support = !!arg;
eb57c1cf0 Rafael J. Wysocki 2007-10-26 365 break;
eb57c1cf0 Rafael J. Wysocki 2007-10-26 366
eb57c1cf0 Rafael J. Wysocki 2007-10-26 367 case SNAPSHOT_POWER_OFF:
eb57c1cf0 Rafael J. Wysocki 2007-10-26 368 if (data->platform_support)
eb57c1cf0 Rafael J. Wysocki 2007-10-26 369 error = hibernation_platform_enter();
eb57c1cf0 Rafael J. Wysocki 2007-10-26 370 break;
eb57c1cf0 Rafael J. Wysocki 2007-10-26 371
37b2ba12d Rafael J. Wysocki 2006-12-06 372 case SNAPSHOT_SET_SWAP_AREA:
d1d241cc2 Rafael J. Wysocki 2007-05-06 373 if (swsusp_swap_in_use()) {
37b2ba12d Rafael J. Wysocki 2006-12-06 374 error = -EPERM;
37b2ba12d Rafael J. Wysocki 2006-12-06 375 } else {
37b2ba12d Rafael J. Wysocki 2006-12-06 376 struct resume_swap_area swap_area;
37b2ba12d Rafael J. Wysocki 2006-12-06 377 dev_t swdev;
37b2ba12d Rafael J. Wysocki 2006-12-06 378
37b2ba12d Rafael J. Wysocki 2006-12-06 379 error = copy_from_user(&swap_area, (void __user *)arg,
37b2ba12d Rafael J. Wysocki 2006-12-06 380 sizeof(struct resume_swap_area));
37b2ba12d Rafael J. Wysocki 2006-12-06 381 if (error) {
37b2ba12d Rafael J. Wysocki 2006-12-06 382 error = -EFAULT;
37b2ba12d Rafael J. Wysocki 2006-12-06 383 break;
37b2ba12d Rafael J. Wysocki 2006-12-06 384 }
37b2ba12d Rafael J. Wysocki 2006-12-06 385
37b2ba12d Rafael J. Wysocki 2006-12-06 386 /*
37b2ba12d Rafael J. Wysocki 2006-12-06 387 * User space encodes device types as two-byte values,
37b2ba12d Rafael J. Wysocki 2006-12-06 388 * so we need to recode them
37b2ba12d Rafael J. Wysocki 2006-12-06 389 */
d88d4050d Jiri Slaby 2010-04-10 390 swdev = new_decode_dev(swap_area.dev);
37b2ba12d Rafael J. Wysocki 2006-12-06 391 if (swdev) {
37b2ba12d Rafael J. Wysocki 2006-12-06 392 offset = swap_area.offset;
7bf236874 Rafael J. Wysocki 2007-01-05 393 data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12d Rafael J. Wysocki 2006-12-06 394 if (data->swap < 0)
37b2ba12d Rafael J. Wysocki 2006-12-06 395 error = -ENODEV;
37b2ba12d Rafael J. Wysocki 2006-12-06 396 } else {
37b2ba12d Rafael J. Wysocki 2006-12-06 397 data->swap = -1;
37b2ba12d Rafael J. Wysocki 2006-12-06 398 error = -EINVAL;
37b2ba12d Rafael J. Wysocki 2006-12-06 399 }
37b2ba12d Rafael J. Wysocki 2006-12-06 400 }
37b2ba12d Rafael J. Wysocki 2006-12-06 401 break;
37b2ba12d Rafael J. Wysocki 2006-12-06 402
6e1819d61 Rafael J. Wysocki 2006-03-23 403 default:
6e1819d61 Rafael J. Wysocki 2006-03-23 404 error = -ENOTTY;
6e1819d61 Rafael J. Wysocki 2006-03-23 405
6e1819d61 Rafael J. Wysocki 2006-03-23 406 }
25f2f3daa Rafael J. Wysocki 2008-06-11 407
942f40155 Rafael J. Wysocki 2013-08-30 408 unlock_device_hotplug();
55f2503c3 Pingfan Liu 2018-07-31 409 mutex_unlock(&system_transition_mutex);
25f2f3daa Rafael J. Wysocki 2008-06-11 410
6e1819d61 Rafael J. Wysocki 2006-03-23 @411 return error;
6e1819d61 Rafael J. Wysocki 2006-03-23 412 }
6e1819d61 Rafael J. Wysocki 2006-03-23 413
:::::: The code at line 411 was first introduced by commit
:::::: 6e1819d615f24ce0726a7d0bd3dd0152d7b21654 [PATCH] swsusp: userland interface
:::::: TO: Rafael J. Wysocki <rjw@sisk.pl>
:::::: CC: Linus Torvalds <torvalds@g5.osdl.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index ecc31e8e40d0..0dda6a9f0af1 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -271,10 +271,14 @@ static int create_image(int platform_mode) { int error; + error = snapshot_prepare_hash(false); + if (error) + return error; + error = dpm_suspend_end(PMSG_FREEZE); if (error) { pr_err("Some devices failed to power down, aborting hibernation\n"); - return error; + goto finish_hash; } error = platform_pre_snapshot(platform_mode); @@ -331,6 +335,9 @@ static int create_image(int platform_mode) dpm_resume_start(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + finish_hash: + snapshot_finish_hash(); + return error; } @@ -694,6 +701,14 @@ int hibernate(void) return -EPERM; } + error = snapshot_key_init(); + if (error) + return error; + + error = snapshot_create_trampoline(); + if (error) + return error; + lock_system_sleep(); /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { @@ -750,6 +765,7 @@ int hibernate(void) pm_restore_gfp_mask(); } else { pm_pr_dbg("Image restored successfully.\n"); + snapshot_restore_trampoline(); } Free_bitmaps: diff --git a/kernel/power/power.h b/kernel/power/power.h index fe2dfa0d4d36..c614b0a294e3 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -11,6 +11,10 @@ #define SNAPSHOT_KEY_SIZE SHA512_DIGEST_SIZE #define DERIVED_KEY_SIZE SHA512_DIGEST_SIZE +/* HMAC algorithm for hibernate snapshot signature */ +#define SNAPSHOT_HMAC "hmac(sha512)" +#define SNAPSHOT_DIGEST_SIZE SHA512_DIGEST_SIZE + struct swsusp_info { struct new_utsname uts; u32 version_code; @@ -19,6 +23,17 @@ struct swsusp_info { unsigned long image_pages; unsigned long pages; unsigned long size; + unsigned long trampoline_pfn; + u8 signature[SNAPSHOT_DIGEST_SIZE]; +} __aligned(PAGE_SIZE); + +/* + * The trampoline page is used to forward information + * from boot kernel to image kernel in restore stage. + */ +struct trampoline { + bool snapshot_key_valid; + int sig_verify_ret; } __aligned(PAGE_SIZE); #ifdef CONFIG_HIBERNATION @@ -27,12 +42,19 @@ extern void __init hibernate_reserved_size_init(void); extern void __init hibernate_image_size_init(void); #ifdef CONFIG_HIBERNATION_ENC_AUTH +/* kernel/power/snapshot.c */ +extern int snapshot_image_verify_decrypt(void); +extern int snapshot_prepare_hash(bool may_sleep); +extern void snapshot_finish_hash(void); /* kernel/power/snapshot_key.c */ extern int snapshot_key_init(void); extern bool snapshot_key_initialized(void); extern int snapshot_get_auth_key(u8 *auth_key, bool may_sleep); extern int snapshot_get_enc_key(u8 *enc_key, bool may_sleep); #else +static inline int snapshot_image_verify_decrypt(void) { return 0; } +static inline int snapshot_prepare_hash(bool may_sleep) { return 0; } +static inline void snapshot_finish_hash(void) {} static inline int snapshot_key_init(void) { return 0; } #endif /* !CONFIG_HIBERNATION_ENC_AUTH */ @@ -171,6 +193,10 @@ extern int snapshot_read_next(struct snapshot_handle *handle); extern int snapshot_write_next(struct snapshot_handle *handle); extern void snapshot_write_finalize(struct snapshot_handle *handle); extern int snapshot_image_loaded(struct snapshot_handle *handle); +extern int snapshot_create_trampoline(void); +extern void snapshot_init_trampoline(void); +extern void snapshot_restore_trampoline(void); +extern void snapshot_free_trampoline(void); /* If unset, the snapshot device cannot be open. */ extern atomic_t snapshot_device_available; diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 640b2034edd6..e817c035f378 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -33,12 +33,16 @@ #include <linux/compiler.h> #include <linux/ktime.h> #include <linux/set_memory.h> +#include <linux/vmalloc.h> #include <linux/uaccess.h> #include <asm/mmu_context.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> #include <asm/io.h> +#ifdef CONFIG_HIBERNATION_ENC_AUTH +#include <crypto/hash.h> +#endif #include "power.h" @@ -79,6 +83,15 @@ static inline void hibernate_restore_protect_page(void *page_address) {} static inline void hibernate_restore_unprotect_page(void *page_address) {} #endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ +/* the trampoline is used by image kernel */ +static void *trampoline_virt; + +/* trampoline pfn from swsusp_info in snapshot for snapshot_write_next() */ +static unsigned long trampoline_pfn; + +/* Keep the buffer for foward page in snapshot_write_next() */ +static void *trampoline_buff; + static int swsusp_page_is_free(struct page *); static void swsusp_set_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *); @@ -1393,8 +1406,246 @@ static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) } #endif /* CONFIG_HIGHMEM */ -static void copy_data_pages(struct memory_bitmap *copy_bm, - struct memory_bitmap *orig_bm) +/* Total number of image pages */ +static unsigned int nr_copy_pages; + +/* Point array for collecting buffers' address in snapshot_write_next() */ +static void **h_buf; + +#ifdef CONFIG_HIBERNATION_ENC_AUTH +/* + * Signature of snapshot image + */ +static u8 signature[SNAPSHOT_DIGEST_SIZE]; + +/* Keep the signature verification result for trampoline */ +static int sig_verify_ret; + +/* keep the snapshot key status for trampoline */ +static bool snapshot_key_valid; + +static u8 *s4_verify_digest; +static struct shash_desc *s4_verify_desc; + +int snapshot_prepare_hash(bool may_sleep) +{ + char auth_key[DERIVED_KEY_SIZE]; + struct crypto_shash *tfm; + size_t digest_size, desc_size; + int ret; + + ret = snapshot_get_auth_key(auth_key, may_sleep); + if (ret) { + pr_warn_once("auth key is invalid: %d\n", ret); + return -EINVAL; + } + snapshot_key_valid = true; + + tfm = crypto_alloc_shash(SNAPSHOT_HMAC, 0, 0); + if (IS_ERR(tfm)) { + pr_err("Allocate HMAC failed: %ld\n", PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + + ret = crypto_shash_setkey(tfm, auth_key, DERIVED_KEY_SIZE); + if (ret) { + pr_err("Set HMAC key failed\n"); + goto error; + } + + desc_size = crypto_shash_descsize(tfm) + sizeof(*s4_verify_desc); + digest_size = crypto_shash_digestsize(tfm); + s4_verify_digest = kzalloc(digest_size + desc_size, + may_sleep ? GFP_KERNEL : GFP_ATOMIC); + if (!s4_verify_digest) { + pr_err("Allocate digest failed\n"); + ret = -ENOMEM; + goto error; + } + + s4_verify_desc = (void *) s4_verify_digest + digest_size; + s4_verify_desc->tfm = tfm; + if (may_sleep) + s4_verify_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + ret = crypto_shash_init(s4_verify_desc); + if (ret < 0) + goto free_shash; + + return 0; + + free_shash: + kfree(s4_verify_digest); + error: + crypto_free_shash(tfm); + s4_verify_digest = NULL; + s4_verify_desc = NULL; + return ret; +} + +void snapshot_finish_hash(void) +{ + if (s4_verify_desc) + crypto_free_shash(s4_verify_desc->tfm); + kfree(s4_verify_digest); + s4_verify_desc = NULL; + s4_verify_digest = NULL; +} + +int snapshot_image_verify_decrypt(void) +{ + int ret, i; + + if (!h_buf) { + ret = -ENOMEM; + goto error; + } + + ret = snapshot_key_init(); + if (ret) + goto error_prep; + + ret = snapshot_prepare_hash(true); + if (ret || !s4_verify_desc) + goto error_prep; + + for (i = 0; i < nr_copy_pages; i++) { + ret = crypto_shash_update(s4_verify_desc, *(h_buf + i), PAGE_SIZE); + if (ret) + goto error_shash; + } + + ret = crypto_shash_final(s4_verify_desc, s4_verify_digest); + if (ret) + goto error_shash; + + pr_debug("Signature %*phN\n", SNAPSHOT_DIGEST_SIZE, signature); + pr_debug("Digest %*phN\n", SNAPSHOT_DIGEST_SIZE, s4_verify_digest); + if (memcmp(signature, s4_verify_digest, SNAPSHOT_DIGEST_SIZE)) + ret = -EKEYREJECTED; + + error_shash: + snapshot_finish_hash(); + + error_prep: + vfree(h_buf); + if (ret) + pr_warn("Signature verification failed: %d\n", ret); + error: + sig_verify_ret = ret; + return ret; +} + +static int +__copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) +{ + unsigned long pfn, dst_pfn; + struct page *d_page; + void *crypto_buffer = NULL; + int ret = 0; + + memory_bm_position_reset(orig_bm); + memory_bm_position_reset(copy_bm); + for (;;) { + pfn = memory_bm_next_pfn(orig_bm); + if (unlikely(pfn == BM_END_OF_MAP)) + break; + dst_pfn = memory_bm_next_pfn(copy_bm); + copy_data_page(dst_pfn, pfn); + + /* Setup buffer */ + d_page = pfn_to_page(dst_pfn); + if (PageHighMem(d_page)) { + void *kaddr = kmap_atomic(d_page); + + copy_page(buffer, kaddr); + kunmap_atomic(kaddr); + crypto_buffer = buffer; + } else { + crypto_buffer = page_address(d_page); + } + + /* Generate digest */ + if (!s4_verify_desc) + continue; + ret = crypto_shash_update(s4_verify_desc, crypto_buffer, + PAGE_SIZE); + if (ret) + return ret; + } + + if (s4_verify_desc) { + ret = crypto_shash_final(s4_verify_desc, s4_verify_digest); + if (ret) + return ret; + + memset(signature, 0, SNAPSHOT_DIGEST_SIZE); + memcpy(signature, s4_verify_digest, SNAPSHOT_DIGEST_SIZE); + } + + return 0; +} + +static void alloc_h_buf(void) +{ + h_buf = vmalloc(sizeof(void *) * nr_copy_pages); + if (!h_buf) + pr_err("Allocate buffer point array failed\n"); +} + +static void init_signature(struct swsusp_info *info) +{ + memcpy(info->signature, signature, SNAPSHOT_DIGEST_SIZE); +} + +static void load_signature(struct swsusp_info *info) +{ + memset(signature, 0, SNAPSHOT_DIGEST_SIZE); + memcpy(signature, info->signature, SNAPSHOT_DIGEST_SIZE); +} + +static void init_sig_verify(struct trampoline *t) +{ + t->sig_verify_ret = sig_verify_ret; + t->snapshot_key_valid = snapshot_key_valid; + sig_verify_ret = 0; + snapshot_key_valid = 0; +} + +static void handle_sig_verify(struct trampoline *t) +{ + if (t->sig_verify_ret) + pr_warn("Signature verification failed: %d\n", + t->sig_verify_ret); + else if (t->snapshot_key_valid) + pr_info("Signature verification passed.\n"); +} +#else +static int +__copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) +{ + unsigned long pfn; + + memory_bm_position_reset(orig_bm); + memory_bm_position_reset(copy_bm); + for (;;) { + pfn = memory_bm_next_pfn(orig_bm); + if (unlikely(pfn == BM_END_OF_MAP)) + break; + copy_data_page(memory_bm_next_pfn(copy_bm), pfn); + } + + return 0; +} + +static inline void alloc_h_buf(void) {} +static inline void init_signature(struct swsusp_info *info) {} +static inline void load_signature(struct swsusp_info *info) {} +static inline void init_sig_verify(struct trampoline *t) {} +static inline void handle_sig_verify(struct trampoline *t) {} +#endif /* !CONFIG_HIBERNATION_ENC_AUTH */ + +static int copy_data_pages(struct memory_bitmap *copy_bm, + struct memory_bitmap *orig_bm) { struct zone *zone; unsigned long pfn; @@ -1408,18 +1659,9 @@ static void copy_data_pages(struct memory_bitmap *copy_bm, if (page_is_saveable(zone, pfn)) memory_bm_set_bit(orig_bm, pfn); } - memory_bm_position_reset(orig_bm); - memory_bm_position_reset(copy_bm); - for(;;) { - pfn = memory_bm_next_pfn(orig_bm); - if (unlikely(pfn == BM_END_OF_MAP)) - break; - copy_data_page(memory_bm_next_pfn(copy_bm), pfn); - } + return __copy_data_pages(copy_bm, orig_bm); } -/* Total number of image pages */ -static unsigned int nr_copy_pages; /* Number of pages needed for saving the original pfns of the image pages */ static unsigned int nr_meta_pages; /* @@ -1961,6 +2203,7 @@ static int swsusp_alloc(struct memory_bitmap *copy_bm, asmlinkage __visible int swsusp_save(void) { unsigned int nr_pages, nr_highmem; + int ret; pr_info("Creating hibernation image:\n"); @@ -1984,7 +2227,11 @@ asmlinkage __visible int swsusp_save(void) * Kill them. */ drain_local_pages(NULL); - copy_data_pages(©_bm, &orig_bm); + ret = copy_data_pages(©_bm, &orig_bm); + if (ret) { + pr_err("Copy data pages failed\n"); + return ret; + } /* * End of critical section. From now on, we can write to memory, @@ -2038,10 +2285,98 @@ static int init_header(struct swsusp_info *info) info->pages = snapshot_get_image_size(); info->size = info->pages; info->size <<= PAGE_SHIFT; + info->trampoline_pfn = page_to_pfn(virt_to_page(trampoline_virt)); + init_signature(info); return init_header_complete(info); } /** + * create trampoline - Create a trampoline page before snapshot be created + * In hibernation process, this routine will be called by kernel before + * the snapshot image be created. It can be used in resuming process. + */ +int snapshot_create_trampoline(void) +{ + if (trampoline_virt) { + pr_warn("Tried to create trampoline again\n"); + return 0; + } + + trampoline_virt = (void *)get_zeroed_page(GFP_KERNEL); + if (!trampoline_virt) { + pr_err("Allocate trampoline page failed\n"); + return -ENOMEM; + } + trampoline_pfn = 0; + trampoline_buff = NULL; + + return 0; +} + +/** + * initial trampoline - Put data to trampoline buffer for target kernel + * + * In resuming process, this routine will be called by boot kernel before + * the target kernel be restored. The boot kernel uses trampoline buffer + * to transfer information to target kernel. + */ +void snapshot_init_trampoline(void) +{ + struct trampoline *t; + + if (!trampoline_pfn || !trampoline_buff) { + pr_err("Did not find trampoline buffer, pfn: %ld\n", + trampoline_pfn); + return; + } + + hibernate_restore_unprotect_page(trampoline_buff); + memset(trampoline_buff, 0, PAGE_SIZE); + t = (struct trampoline *)trampoline_buff; + + init_sig_verify(t); + + pr_info("Hibernation trampoline page prepared\n"); +} + +/** + * restore trampoline - Handle the data from boot kernel and free. + * + * In resuming process, this routine will be called by target kernel + * after target kernel is restored. The target kernel handles + * the data in trampoline that it is transferred from boot kernel. + */ +void snapshot_restore_trampoline(void) +{ + struct trampoline *t; + + if (!trampoline_virt) { + pr_err("Doesn't have trampoline page\n"); + return; + } + + t = (struct trampoline *)trampoline_virt; + + handle_sig_verify(t); + snapshot_free_trampoline(); +} + +void snapshot_free_trampoline(void) +{ + if (!trampoline_virt) { + pr_err("No trampoline page can be freed\n"); + return; + } + + trampoline_pfn = 0; + trampoline_buff = NULL; + memset(trampoline_virt, 0, PAGE_SIZE); + free_page((unsigned long)trampoline_virt); + trampoline_virt = NULL; + pr_info("Trampoline freed\n"); +} + +/** * pack_pfns - Prepare PFNs for saving. * @bm: Memory bitmap. * @buf: Memory buffer to store the PFNs in. @@ -2188,6 +2523,8 @@ static int load_header(struct swsusp_info *info) if (!error) { nr_copy_pages = info->image_pages; nr_meta_pages = info->pages - info->image_pages - 1; + trampoline_pfn = info->trampoline_pfn; + load_signature(info); } return error; } @@ -2521,7 +2858,8 @@ static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) * Get the address that snapshot_write_next() should return to its caller to * write to. */ -static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) +static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca, + unsigned long *pfn_out) { struct pbe *pbe; struct page *page; @@ -2530,6 +2868,9 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) if (pfn == BM_END_OF_MAP) return ERR_PTR(-EFAULT); + if (pfn_out) + *pfn_out = pfn; + page = pfn_to_page(pfn); if (PageHighMem(page)) return get_highmem_page_buffer(page, ca); @@ -2577,6 +2918,7 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) int snapshot_write_next(struct snapshot_handle *handle) { static struct chain_allocator ca; + unsigned long pfn; int error = 0; /* Check if we have already loaded the entire image */ @@ -2601,6 +2943,12 @@ int snapshot_write_next(struct snapshot_handle *handle) safe_pages_list = NULL; + /* Allocate buffer point array for generating + * digest to compare with signature. + * h_buf will freed in snapshot_image_verify_decrypt(). + */ + alloc_h_buf(); + error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); if (error) return error; @@ -2624,21 +2972,28 @@ int snapshot_write_next(struct snapshot_handle *handle) chain_init(&ca, GFP_ATOMIC, PG_SAFE); memory_bm_position_reset(&orig_bm); restore_pblist = NULL; - handle->buffer = get_buffer(&orig_bm, &ca); + handle->buffer = get_buffer(&orig_bm, &ca, &pfn); handle->sync_read = 0; if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); + if (h_buf) + *h_buf = handle->buffer; } } else { copy_last_highmem_page(); /* Restore page key for data page (s390 only). */ page_key_write(handle->buffer); hibernate_restore_protect_page(handle->buffer); - handle->buffer = get_buffer(&orig_bm, &ca); + handle->buffer = get_buffer(&orig_bm, &ca, &pfn); if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); if (handle->buffer != buffer) handle->sync_read = 0; + /* Capture the trampoline for transfer data */ + if (pfn == trampoline_pfn && trampoline_pfn) + trampoline_buff = handle->buffer; + if (h_buf) + *(h_buf + (handle->cur - nr_meta_pages - 1)) = handle->buffer; } handle->cur++; return PAGE_SIZE; diff --git a/kernel/power/swap.c b/kernel/power/swap.c index d7f6c1a288d3..2e669f589830 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -1095,6 +1095,9 @@ static int load_image(struct swap_map_handle *handle, snapshot_write_finalize(snapshot); if (!snapshot_image_loaded(snapshot)) ret = -ENODATA; + if (!ret) + ret = snapshot_image_verify_decrypt(); + snapshot_init_trampoline(); } swsusp_show_speed(start, stop, nr_to_read, "Read"); return ret; @@ -1447,6 +1450,9 @@ static int load_image_lzo(struct swap_map_handle *handle, } } } + if (!ret) + ret = snapshot_image_verify_decrypt(); + snapshot_init_trampoline(); } swsusp_show_speed(start, stop, nr_to_read, "Read"); out_clean: diff --git a/kernel/power/user.c b/kernel/power/user.c index 2d8b60a3c86b..d5c8f777e8d8 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -248,6 +248,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, if (!data->frozen || data->ready) break; pm_restore_gfp_mask(); + snapshot_restore_trampoline(); free_basic_memory_bitmaps(); data->free_bitmaps = false; thaw_processes(); @@ -259,6 +260,12 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, error = -EPERM; break; } + error = snapshot_key_init(); + if (error) + return error; + error = snapshot_create_trampoline(); + if (error) + return error; pm_restore_gfp_mask(); error = hibernation_snapshot(data->platform_support); if (!error) { @@ -275,6 +282,11 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, error = -EPERM; break; } + if (snapshot_image_verify_decrypt()) { + error = -EPERM; + break; + } + snapshot_init_trampoline(); error = hibernation_restore(data->platform_support); break;
When producing memory snapshot image, hibernation uses HMAC-SHA512 with snapshot key (from TPM trusted key) to calculate the hash of all data pages in snapshot image. The hash result will be kept in the snapshot header as the image signature. Before hibernation restores image, kernel executes HMAC-SHA512 again and compares the result with the signature in the header to verify the integrity of snapshot image. If the verification failed, the resume process will be stopped. Then the snapshot image will be discarded and system will boot as normal. On the other hand, a trampoline page be created in snapshot image when hibernation. This trampoline page be used to forward the state of snapshot key and the result of snapshot image verification from boot kernel to image kernel when resuming. The trampoline page will also be used to forward the snapshot key in the later patch. Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Chen Yu <yu.c.chen@intel.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Ryan Chen <yu.chen.surf@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Giovanni Gherdovich <ggherdovich@suse.cz> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Jann Horn <jannh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com> --- kernel/power/hibernate.c | 18 ++- kernel/power/power.h | 26 ++++ kernel/power/snapshot.c | 387 +++++++++++++++++++++++++++++++++++++++++++++-- kernel/power/swap.c | 6 + kernel/power/user.c | 12 ++ 5 files changed, 432 insertions(+), 17 deletions(-)