syzbot

 sign-in | mailing list | source | docs
🐞 Open [1163] 🐞 Fixed [4320] 🐞 Invalid [9666] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes

KASAN: use-after-free Read in __list_del_entry_valid (2)

Status: fixed on 2018/01/11 01:23
Reported-by: syzbot+29cf0a34886ca39d13fc0451b174140973b5bed3@syzkaller.appspotmail.com
Fix commit: d76c68109f37 crypto: pcrypt - fix freeing pcrypt instances
First crash: 1880d, last: 1873d
duplicates (13):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
BUG: unable to handle kernel paging request in socket_file_ops C 1 1876d 1873d 0/24 closed as dup on 2017/12/20 22:39
BUG: bad usercopy in memdup_user 107 1855d 1875d 0/24 closed as dup on 2017/12/31 08:11
general protection fault in copy_user_generic_unrolled (2) 1 1875d 1871d 0/24 closed as dup on 2017/12/31 08:14
BUG: bad usercopy in ___sys_sendmsg 70 1854d 1877d 0/24 closed as dup on 2017/12/31 08:10
BUG: unable to handle kernel NULL pointer dereference in irq_may_run C 1 1873d 1872d 0/24 closed as dup on 2017/12/23 20:38
BUG: bad usercopy in old_dev_ioctl 13 1857d 1876d 0/24 closed as dup on 2017/12/31 08:10
KASAN: use-after-free Read in __pagevec_lru_add_fn C 1 1875d 1871d 0/24 closed as dup on 2017/12/22 22:25
general protection fault in strncpy_from_user 1 1876d 1872d 0/24 closed as dup on 2017/12/31 08:14
BUG: unable to handle kernel NULL pointer dereference in __crypto_alg_lookup C 47 1873d 1875d 0/24 closed as dup on 2017/12/20 22:36
BUG: bad usercopy in memdup_user_nul 5 1861d 1874d 0/24 closed as dup on 2017/12/31 08:11
BUG: unable to handle kernel paging request in security_compute_sid C 1 1875d 1871d 0/24 closed as dup on 2017/12/22 22:14
BUG: unable to handle kernel NULL pointer dereference in sidtab_search_core C 1 1878d 1873d 0/24 closed as dup on 2017/12/22 17:05
KASAN: use-after-free Read in crypto_aead_free_instance C 5 1869d 1873d 0/24 closed as dup on 2017/12/20 22:37
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in __list_del_entry_valid (3) C 15 1784d 1797d 24/24 closed as dup on 2018/03/22 15:31
upstream KASAN: use-after-free Read in __list_del_entry_valid (4) C done 16 1090d 1777d 17/24 fixed on 2020/05/10 10:41

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0x11d/0x150 lib/list_debug.c:42
Read of size 8 at addr ffff8801c525d208 by task syzkaller184222/6821

CPU: 1 PID: 6821 Comm: syzkaller184222 Not tainted 4.15.0-rc3+ #222
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 __list_del_entry_valid+0x11d/0x150 lib/list_debug.c:42
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 crypto_larval_kill+0x79/0x2e0 crypto/api.c:164
 crypto_alg_mod_lookup+0x178/0x1b0 crypto/api.c:283
 crypto_find_alg crypto/api.c:501 [inline]
 crypto_alloc_tfm+0xf3/0x2f0 crypto/api.c:534
 crypto_alloc_aead+0x2c/0x40 crypto/aead.c:342
 aead_bind+0x70/0x140 crypto/algif_aead.c:482
 alg_bind+0x1ab/0x440 crypto/af_alg.c:179
 SYSC_bind+0x1b4/0x3f0 net/socket.c:1454
 SyS_bind+0x24/0x30 net/socket.c:1440
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4406f9
RSP: 002b:00007ffe05f4b6d8 EFLAGS: 00000203 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004406f9
RDX: 0000000000000058 RSI: 0000000020269000 RDI: 0000000000000003
RBP: 0000000000007a10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000000000
R13: 0000000000401c30 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 6821:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610
 kmalloc include/linux/slab.h:499 [inline]
 kzalloc include/linux/slab.h:688 [inline]
 crypto_larval_alloc+0x51/0x1e0 crypto/api.c:114
 crypto_larval_add crypto/api.c:136 [inline]
 crypto_larval_lookup.part.8+0x194/0x400 crypto/api.c:232
 crypto_larval_lookup crypto/api.c:212 [inline]
 crypto_alg_mod_lookup+0x77/0x1b0 crypto/api.c:271
 crypto_find_alg crypto/api.c:501 [inline]
 crypto_alloc_tfm+0xf3/0x2f0 crypto/api.c:534
 crypto_alloc_aead+0x2c/0x40 crypto/aead.c:342
 aead_bind+0x70/0x140 crypto/algif_aead.c:482
 alg_bind+0x1ab/0x440 crypto/af_alg.c:179
 SYSC_bind+0x1b4/0x3f0 net/socket.c:1454
 SyS_bind+0x24/0x30 net/socket.c:1440
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 3209:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3488 [inline]
 kfree+0xca/0x250 mm/slab.c:3803
 crypto_larval_destroy+0x110/0x150 crypto/api.c:107
 crypto_alg_put crypto/internal.h:116 [inline]
 crypto_larval_kill+0x1e8/0x2e0 crypto/api.c:167
 crypto_wait_for_test+0x87/0xb0 crypto/algapi.c:351
 crypto_register_instance+0x2bf/0x430 crypto/algapi.c:558
 aead_register_instance+0x161/0x1c0 crypto/aead.c:421
 pcrypt_create_aead crypto/pcrypt.c:322 [inline]
 pcrypt_create+0x542/0x6c0 crypto/pcrypt.c:346
 cryptomgr_probe+0x74/0x240 crypto/algboss.c:75
 kthread+0x37a/0x440 kernel/kthread.c:238
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441

The buggy address belongs to the object at ffff8801c525d200
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 8 bytes inside of
 1024-byte region [ffff8801c525d200, ffff8801c525d600)
The buggy address belongs to the page:
page:00000000d279a1bb count:1 mapcount:0 mapping:00000000a05ea903 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801c525c000 0000000000000000 0000000100000007
raw: ffffea00071858a0 ffffea0007124420 ffff8801db000ac0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c525d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801c525d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801c525d200: fb fb fb fb 00 00 00 00 00 00 00 00 00 00 00 00
                      ^
 ffff8801c525d280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c525d300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (11):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-upstream-kasan-gce 2017/12/15 23:04 upstream 032b4cc8ff84 ac20b98c .config console log report syz C
ci-upstream-kasan-gce 2017/12/15 07:11 upstream d455df0bcc00 ac20b98c .config console log report syz C
ci-upstream-kasan-gce 2017/12/13 21:29 upstream d39a01eff9af 06ea774d .config console log report syz C
ci-upstream-net-kasan-gce 2017/12/17 00:02 net-next 28dc4c8f4557 b6f0c91b .config console log report syz C
ci-upstream-net-kasan-gce 2017/12/15 22:53 net-next 3b07d7884ca2 ac20b98c .config console log report syz C
ci-upstream-net-kasan-gce 2017/12/15 07:03 net-next 5c13e07580c8 ac20b98c .config console log report syz C
ci-upstream-net-kasan-gce 2017/12/13 21:16 net-next f93ea3bf151d 06ea774d .config console log report syz C
ci-upstream-mmots-kasan-gce 2017/12/20 00:12 mmots 82bcf1def3b5 af9163c7 .config console log report syz C
ci-upstream-mmots-kasan-gce 2017/12/19 18:35 mmots 82bcf1def3b5 af9163c7 .config console log report syz C
ci-upstream-mmots-kasan-gce 2017/12/18 11:48 mmots 82bcf1def3b5 d5beb42a .config console log report syz C
ci-upstream-mmots-kasan-gce 2017/12/17 10:30 mmots 82bcf1def3b5 b6f0c91b .config console log report syz C
* Struck through repros no longer work on HEAD.