syzbot


KCSAN: data-race in generic_fillattr / setattr_copy (6)

Status: moderation: reported on 2026/02/24 05:16
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+eff3c7ecf7813729d2f6@syzkaller.appspotmail.com
First crash: 5d15h, last: 5d15h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
e09f3068-1a72-4ab9-9f4b-ee5798b535de assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in generic_fillattr / setattr_copy (6) 2026/02/24 05:15 2026/02/24 05:15 2026/02/24 05:20 305c0ec5cd886e2d13738e28e1b2df9b0ec20fc9
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in generic_fillattr / setattr_copy (4) fs 6 1 229d 229d 0/29 auto-obsoleted due to no activity on 2025/09/09 10:55
upstream KCSAN: data-race in generic_fillattr / setattr_copy (3) fs 6 2 384d 388d 0/29 auto-obsoleted due to no activity on 2025/04/07 04:31
upstream KCSAN: data-race in generic_fillattr / setattr_copy (2) fs 6 1 458d 458d 0/29 auto-obsoleted due to no activity on 2025/01/23 14:54
upstream KCSAN: data-race in generic_fillattr / setattr_copy fs 6 1 767d 767d 0/29 auto-obsoleted due to no activity on 2024/02/28 21:09
upstream KCSAN: data-race in generic_fillattr / setattr_copy (5) fs 6 2 68d 88d 0/29 auto-obsoleted due to no activity on 2026/02/17 14:54

Sample crash report:
==================================================================
BUG: KCSAN: data-race in generic_fillattr / setattr_copy

write to 0xffff88811746154c of 4 bytes by task 3609 on cpu 1:
 inode_set_mtime_to_ts include/linux/fs.h:1659 [inline]
 setattr_copy+0x2de/0x4a0 fs/attr.c:363
 shmem_setattr+0x5be/0x7c0 mm/shmem.c:1385
 notify_change+0x872/0x8f0 fs/attr.c:556
 vfs_utimes+0x2fc/0x440 fs/utimes.c:67
 do_utimes_path fs/utimes.c:99 [inline]
 do_utimes+0x14d/0x210 fs/utimes.c:139
 __do_sys_utimensat fs/utimes.c:158 [inline]
 __se_sys_utimensat fs/utimes.c:142 [inline]
 __x64_sys_utimensat+0xc4/0x190 fs/utimes.c:142
 x64_sys_call+0x2bca/0x3020 arch/x86/include/generated/asm/syscalls_64.h:281
 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 0xffff88811746154c of 4 bytes by task 3306 on cpu 0:
 inode_get_mtime_nsec include/linux/fs.h:1645 [inline]
 inode_get_mtime include/linux/fs.h:1651 [inline]
 generic_fillattr+0x20e/0x340 fs/stat.c:102
 shmem_getattr+0x181/0x200 mm/shmem.c:1302
 vfs_getattr_nosec+0x146/0x1e0 fs/stat.c:213
 vfs_getattr+0x48/0x60 fs/stat.c:262
 vfs_statx_path+0x28/0x140 fs/stat.c:299
 vfs_statx+0xc4/0x170 fs/stat.c:356
 vfs_fstatat+0x118/0x170 fs/stat.c:373
 __do_sys_newfstatat fs/stat.c:538 [inline]
 __se_sys_newfstatat+0x55/0x3e0 fs/stat.c:532
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:532
 x64_sys_call+0x2c64/0x3020 arch/x86/include/generated/asm/syscalls_64.h:263
 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: 0x1e2411f4 -> 0x1fedd575

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3306 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/24 05:15 upstream 7dff99b35460 41d2fa6a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in generic_fillattr / setattr_copy
* Struck through repros no longer work on HEAD.