syzbot


KCSAN: data-race in dont_mount / step_into

Status: moderation: reported on 2022/05/07 00:44
Reported-by: syzbot+7ab22e852c066cf2af27@syzkaller.appspotmail.com
First crash: 174d, last: 13h28m

Sample crash report:
==================================================================
BUG: KCSAN: data-race in dont_mount / step_into

read-write to 0xffff8881353149c0 of 4 bytes by task 24825 on cpu 0:
 dont_mount+0x27/0x40 include/linux/dcache.h:350
 vfs_unlink+0x27e/0x3e0 fs/namei.c:4231
 do_unlinkat+0x258/0x510 fs/namei.c:4297
 __do_sys_unlink fs/namei.c:4345 [inline]
 __se_sys_unlink fs/namei.c:4343 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4343
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881353149c0 of 4 bytes by task 1436 on cpu 1:
 __follow_mount_rcu fs/namei.c:1480 [inline]
 handle_mounts fs/namei.c:1531 [inline]
 step_into+0xdc/0x7d0 fs/namei.c:1831
 walk_component+0x164/0x230 fs/namei.c:1999
 lookup_last fs/namei.c:2450 [inline]
 path_lookupat+0x11d/0x2b0 fs/namei.c:2474
 filename_lookup+0x133/0x310 fs/namei.c:2503
 user_path_at_empty+0x3e/0x110 fs/namei.c:2876
 do_readlinkat+0x98/0x210 fs/stat.c:456
 __do_sys_readlink fs/stat.c:489 [inline]
 __se_sys_readlink fs/stat.c:486 [inline]
 __x64_sys_readlink+0x43/0x50 fs/stat.c:486
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00600008 -> 0x00008008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1436 Comm: udevd Not tainted 6.0.0-rc7-syzkaller-00042-g46452d3786a8-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
==================================================================

Crashes (278):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/09/28 02:51 upstream 46452d3786a8 75c78242 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/26 08:35 upstream f76349cf4145 d59ba983 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/25 23:55 upstream 5e049663f678 0042f2b4 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/25 04:21 upstream 1a61b828566f 0042f2b4 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/23 14:39 upstream bf682942cd26 0042f2b4 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/22 15:47 upstream dc164f4fb00a 0042f2b4 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/22 12:48 upstream dc164f4fb00a 60af5050 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/21 10:38 upstream 60891ec99e14 380f82fb .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/20 19:07 upstream 60891ec99e14 c4b8ccfd .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/20 16:59 upstream 521a547ced64 c4b8ccfd .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/19 12:36 upstream 521a547ced64 dd9a85ff .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/19 07:32 upstream 521a547ced64 dd9a85ff .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/18 18:04 upstream 38eddeedbbea dd9a85ff .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/17 06:10 upstream a335366bad13 dd9a85ff .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/14 09:55 upstream 3245cb65fd91 b884348d .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/13 13:51 upstream d1221cea11fc a08652b0 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/13 08:14 upstream e839a756012b a08652b0 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/12 16:50 upstream 80e78fcce86d f371ed7e .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/12 09:57 upstream 80e78fcce86d 356d8217 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/10 20:29 upstream b96fbd602d35 356d8217 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/09 23:34 upstream ce888220d5c7 356d8217 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/09 12:50 upstream 9b4509495418 90058bdc .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/09 10:36 upstream 506357871c18 90058bdc .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/09 02:38 upstream 506357871c18 f3027468 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/08 13:09 upstream 26b1224903b3 f3027468 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/07 11:48 upstream 0066f1b0e275 c5b7bc57 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/06 23:38 upstream d2ec799d1c1b 5fc30c37 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/06 10:49 upstream 53e99dcff61e 65aea2b9 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/06 01:57 upstream 53e99dcff61e 9dcd38fc .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/04 07:22 upstream 7726d4c3e60b 28811d0a .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/03 18:34 upstream 42cf58c272ee 28811d0a .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/03 14:25 upstream d895ec7938c4 28811d0a .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/02 19:20 upstream 0b3acd1cc022 25194605 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/02 15:48 upstream 42e66b1cc3a0 25194605 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/02 03:27 upstream 42e66b1cc3a0 a805568e .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/01 17:24 upstream 2880e1a175b9 86c46e46 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/01 14:14 upstream c5e4d5e99162 86c46e46 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/09/01 02:37 upstream c5e4d5e99162 b01ec571 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/31 10:44 upstream dcf8e5633e2e 51e54e30 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/30 05:28 upstream dcf8e5633e2e 4a380809 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/29 15:50 upstream b90cb1053190 d7593c58 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/28 21:05 upstream 8379c0b31fbc 07177916 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/26 13:55 upstream 4c612826bec1 e5a303f1 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/23 22:00 upstream df0219d11b6f cea8b0f7 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/23 02:09 upstream 072e51356cd5 26a13b38 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/22 10:27 upstream 1c23f9e627a7 26a13b38 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/21 08:16 upstream 15b3f48a4339 26a13b38 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/19 23:23 upstream 50cd95ac4654 26a13b38 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/08/19 10:43 upstream 4c2d0b039c5c 26a13b38 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/05/06 23:52 upstream 64267926e01b e60b1103 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/05/06 21:37 upstream 64267926e01b e60b1103 .config log report info KCSAN: data-race in dont_mount / step_into
ci2-upstream-kcsan-gce 2022/04/07 05:11 upstream 3e732ebf7316 53c67432 .config log report info KCSAN: data-race in dont_mount / step_into
* Struck through repros no longer work on HEAD.