syzbot


KCSAN: data-race in atime_needs_update / inode_set_ctime_current

Status: moderation: reported on 2023/12/09 00:00
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+55e393c8d287963ea4b1@syzkaller.appspotmail.com
First crash: 898d, last: 3d10h

Sample crash report:
==================================================================
BUG: KCSAN: data-race in atime_needs_update / inode_set_ctime_current

write to 0xffff88811bdaa0e0 of 8 bytes by task 4553 on cpu 1:
 inode_set_ctime_current+0x592/0x810 fs/inode.c:2865
 __simple_unlink fs/libfs.c:793 [inline]
 simple_unlink+0x2d/0x80 fs/libfs.c:808
 shmem_unlink+0x12d/0x140 mm/shmem.c:4020
 vfs_unlink+0x1c7/0x490 fs/namei.c:5470
 filename_unlinkat+0x1e2/0x410 fs/namei.c:5540
 __do_sys_unlink fs/namei.c:5575 [inline]
 __se_sys_unlink+0x2b/0xe0 fs/namei.c:5572
 __x64_sys_unlink+0x1f/0x30 fs/namei.c:5572
 x64_sys_call+0x2eb6/0x3020 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811bdaa0e0 of 8 bytes by task 2998 on cpu 0:
 inode_get_ctime_sec include/linux/fs.h:1684 [inline]
 inode_get_ctime include/linux/fs.h:1694 [inline]
 relatime_need_update fs/inode.c:2071 [inline]
 atime_needs_update+0x2ef/0x3e0 fs/inode.c:2229
 touch_atime+0x4a/0x330 fs/inode.c:2244
 do_readlinkat+0x137/0x2f0 fs/stat.c:582
 __do_sys_readlink fs/stat.c:605 [inline]
 __se_sys_readlink fs/stat.c:602 [inline]
 __x64_sys_readlink+0x47/0x60 fs/stat.c:602
 x64_sys_call+0x2b51/0x3020 arch/x86/include/generated/asm/syscalls_64.h:90
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000698c5bbe -> 0x00000000698c5bc1

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2998 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
==================================================================

Crashes (467):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/11 10:37 upstream dc855b77719f 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/02/04 14:50 upstream 5fd0a1df5d05 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/02/02 10:32 upstream 18f7fcd5e69a 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/30 20:57 upstream 4d310797262f ae7dc18c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/28 11:04 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/28 02:25 upstream 1f97d9dcf536 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/25 23:56 upstream 023777797472 55756628 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/25 18:20 upstream d91a46d6805a 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/24 15:03 upstream 62085877ae65 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/21 21:29 upstream cf38b2340c0e 8fc37797 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/18 23:26 upstream e84d960149e7 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/13 23:50 upstream b54345928fa1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/12 14:06 upstream 0f61b1860cc3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/09 03:24 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2026/01/04 17:25 upstream 54e82e93ca93 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/12/22 01:48 upstream 765b233a9b94 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/12/19 14:47 upstream dd9b004b7ff3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/12/11 10:10 upstream d358e5254674 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/12/07 00:58 upstream cc3ee4ba57b7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/12/02 23:55 upstream 4a26e7032d7d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/11/26 23:37 upstream 4941a17751c9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/11/01 21:11 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/10/10 19:24 upstream 917167ed1211 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/09/02 15:34 upstream b320789d6883 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/08/26 16:35 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/08/09 09:59 upstream 2988dfed8a5d 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/08/07 17:22 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/07/18 23:02 upstream d786aba32000 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/07/16 22:01 upstream 155a3c003e55 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/07/09 09:01 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/06/29 15:45 upstream dfba48a70cb6 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/06/21 08:51 upstream 11313e2f7812 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/06/19 18:42 upstream 24770983ccfe ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/06/09 23:10 upstream 19272b37aa4f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/05/27 01:18 upstream 0ff41df1cb26 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/05/06 03:25 upstream 01f95500a162 ae98e6b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/25 16:33 upstream 02ddfb981de8 e3715315 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/23 02:55 upstream bc3372351d0c 53a8b9bd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/22 03:38 upstream a33b5a08cbbd 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/15 23:34 upstream 1a1d569a75f3 a95239b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/14 06:14 upstream 8ffd015db85f 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/14 01:42 upstream 5aaaedb0cb54 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/12 13:12 upstream 3bde70a2c827 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/12 01:14 upstream e618ee89561b 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/08 20:26 upstream bec7dcbc242c a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/04/05 06:06 upstream a52a3c18cdf3 c53ea9c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/03/31 06:35 upstream aa918db707fb d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/03/30 06:59 upstream 7f2ff7b62617 d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2025/03/26 08:17 upstream 2df0c02dab82 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2023/12/08 14:09 upstream 5e3f5b81de80 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
2023/11/20 12:30 upstream 98b1cc82c4af cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in atime_needs_update / inode_set_ctime_current
* Struck through repros no longer work on HEAD.