KCSAN: data-race in do_timerfd_settime / do_timerfd_settime (4)

Status: auto-obsoleted due to no activity on 2025/04/21 22:26
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+a0e54c9358cb54949bb5@syzkaller.appspotmail.com
First crash: 534d, last: 534d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_timerfd_settime / do_timerfd_settime fs 6 1 1577d 1577d 0/29 auto-closed as invalid on 2022/05/23 15:22
upstream KCSAN: data-race in do_timerfd_settime / do_timerfd_settime (3) fs 6 1 1381d 1381d 0/29 auto-obsoleted due to no activity on 2022/12/05 06:13
upstream KCSAN: data-race in do_timerfd_settime / do_timerfd_settime (2) fs 6 1 1489d 1489d 0/29 auto-closed as invalid on 2022/08/19 07:40

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

write to 0xffff88811560f3d4 of 1 bytes by task 6754 on cpu 0:
 timerfd_setup_cancel fs/timerfd.c:164 [inline]
 do_timerfd_settime+0x94a/0xa30 fs/timerfd.c:478
 __do_sys_timerfd_settime fs/timerfd.c:569 [inline]
 __se_sys_timerfd_settime fs/timerfd.c:560 [inline]
 __x64_sys_timerfd_settime+0xb9/0x140 fs/timerfd.c:560
 x64_sys_call+0x2b76/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:287
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811560f3d4 of 1 bytes by task 6755 on cpu 1:
 timerfd_canceled fs/timerfd.c:151 [inline]
 timerfd_setup fs/timerfd.c:225 [inline]
 do_timerfd_settime+0x867/0xa30 fs/timerfd.c:521
 __do_sys_timerfd_settime fs/timerfd.c:569 [inline]
 __se_sys_timerfd_settime fs/timerfd.c:560 [inline]
 __x64_sys_timerfd_settime+0xb9/0x140 fs/timerfd.c:560
 x64_sys_call+0x2b76/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:287
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6755 Comm: syz.2.994 Tainted: G        W          6.14.0-rc4-syzkaller #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
==================================================================
netlink: 'syz.2.994': attribute type 10 has an invalid length.

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/24 22:25 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in do_timerfd_settime / do_timerfd_settime
* Struck through repros no longer work on HEAD.