syzbot


KCSAN: data-race in fill_mg_cmtime / shmem_unlink

Status: moderation: reported on 2024/11/19 16:50
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+981e2f2af3b7fc150759@syzkaller.appspotmail.com
First crash: 351d, last: 22h01m

Sample crash report:
==================================================================
BUG: KCSAN: data-race in fill_mg_cmtime / shmem_unlink

write to 0xffff8881033b382c of 4 bytes by task 3308 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1839 [inline]
 shmem_unlink+0x13c/0x170 mm/shmem.c:3974
 shmem_rename2+0x1a1/0x290 mm/shmem.c:4063
 vfs_rename+0x7e8/0xa30 fs/namei.c:5216
 do_renameat2+0x52a/0x9e0 fs/namei.c:5364
 __do_sys_rename fs/namei.c:5411 [inline]
 __se_sys_rename fs/namei.c:5409 [inline]
 __x64_sys_rename+0x58/0x70 fs/namei.c:5409
 x64_sys_call+0x1f9/0x3000 arch/x86/include/generated/asm/syscalls_64.h:83
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881033b382c of 4 bytes by task 4576 on cpu 1:
 inode_get_mtime_nsec include/linux/fs.h:1825 [inline]
 inode_get_mtime include/linux/fs.h:1831 [inline]
 fill_mg_cmtime+0x5b/0x260 fs/stat.c:55
 generic_fillattr+0x24a/0x340 fs/stat.c:99
 shmem_getattr+0x181/0x200 mm/shmem.c:1257
 vfs_getattr_nosec+0x146/0x1e0 fs/stat.c:213
 vfs_getattr fs/stat.c:262 [inline]
 vfs_statx_path fs/stat.c:299 [inline]
 vfs_statx+0x113/0x390 fs/stat.c:356
 vfs_fstatat+0x115/0x170 fs/stat.c:375
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat+0x55/0x260 fs/stat.c:536
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:536
 x64_sys_call+0x135a/0x3000 arch/x86/include/generated/asm/syscalls_64.h:263
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x330cb9d1 -> 0x333e0dda

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4576 Comm: udevd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================

Crashes (106):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/05 08:58 upstream 17d85f33a83b a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/11/03 02:07 upstream 6146a0f1dfae 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/31 07:38 upstream d127176862a9 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/25 20:16 upstream 566771afc7a8 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/22 23:18 upstream dd72c8fcf6d3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/20 15:30 upstream 211ddde0823f d422939c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/14 12:03 upstream 3a8660878839 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/13 05:50 upstream 3a8660878839 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/12 19:51 upstream 8765f467912f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/08 18:07 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/08 07:52 upstream 971199ad2a0f 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/03 02:43 upstream e406d57be7bd 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/10/01 07:45 upstream 50c19e20ed2e 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/27 16:01 upstream fec734e8d564 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/25 22:29 upstream 4ff71af020ae 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/25 09:17 upstream bf40f4b87761 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/17 19:13 upstream d4b779985a6c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/16 11:04 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/15 16:44 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/12 17:57 upstream 320475fbd590 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/09 19:44 upstream 9dd1835ecda5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/05 03:59 upstream 08b06c30a445 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/09/04 03:29 upstream b9a10f876409 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/08/27 18:03 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/08/24 20:06 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/08/22 03:29 upstream 3957a5720157 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/08/18 11:19 upstream c17b750b3ad9 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/08/10 09:13 upstream 2b38afce25c4 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/08/03 21:43 upstream 352af6a011d5 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/08/01 11:30 upstream f2d282e1dfb3 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/30 17:42 upstream 4b290aae788e f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/28 13:58 upstream 038d61fd6422 6654ea9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/27 06:01 upstream 302f88ff3584 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/23 17:00 upstream 01a412d06bc5 e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/22 22:41 upstream 89be9a83ccf1 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/20 14:49 upstream f4a40a4282f4 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/18 20:05 upstream d786aba32000 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/16 07:51 upstream 155a3c003e55 124ec9cc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/07/14 23:17 upstream 347e9f5043c8 d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/27 02:54 upstream f02769e7f272 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/26 01:49 upstream 92ca6c498a5e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/24 17:37 upstream 78f4e737a53e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/20 18:27 upstream 75f5f23f8787 804b3919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/17 02:22 upstream 9afe652958c3 cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/15 20:29 upstream 08215f5486ec 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/15 12:31 upstream 8c6bc74c7f89 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2025/06/14 09:34 upstream 02adc1490e6d 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
2024/11/19 16:49 upstream 158f238aa69d 7d02db5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_unlink
* Struck through repros no longer work on HEAD.