syzbot


KCSAN: data-race in aio_read_events / iocb_put (13)

Status: moderation: reported on 2026/01/20 09:17
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+afa258ce86594613760c@syzkaller.appspotmail.com
First crash: 51d, last: 27d
✨ AI Jobs (3)
ID Workflow Result Correct Bug Created Started Finished Revision Error
3aa556b6-49a5-4b1f-863d-9f9da84fb384 repro KCSAN: data-race in aio_read_events / iocb_put (13) 2026/03/07 01:31 2026/03/07 01:31 2026/03/07 01:38 31e9c887f7dc24e04b3ca70d0d54fc34141844b0
be481e9c-9cf6-4c85-b258-d9a4710a79e1 assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in aio_read_events / iocb_put (13) 2026/02/24 18:29 2026/02/24 18:29 2026/02/24 18:32 305c0ec5cd886e2d13738e28e1b2df9b0ec20fc9
7af834cc-253b-47cb-b720-3378f3674ca3 assessment-kcsan 🏃 KCSAN: data-race in aio_read_events / iocb_put (13) 2026/01/22 18:07 2026/01/22 18:07 82c9c083a75aa76345d19c3fc2c0dea5dee268df+
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in aio_read_events / iocb_put (12) fs 6 1 242d 242d 0/29 auto-obsoleted due to no activity on 2025/09/06 20:42
upstream KCSAN: data-race in aio_read_events / iocb_put (11) fs 6 1 668d 668d 0/29 auto-obsoleted due to no activity on 2024/06/16 22:57
upstream KCSAN: data-race in aio_read_events / iocb_put (7) fs 6 1 999d 999d 0/29 auto-obsoleted due to no activity on 2023/07/22 02:26
upstream KCSAN: data-race in aio_read_events / iocb_put (5) fs 6 1 1415d 1415d 0/29 auto-closed as invalid on 2022/06/01 10:01
upstream KCSAN: data-race in aio_read_events / iocb_put (10) fs 6 1 741d 741d 0/29 auto-obsoleted due to no activity on 2024/04/05 02:13
upstream KCSAN: data-race in aio_read_events / iocb_put (9) fs 6 2 823d 822d 0/29 auto-obsoleted due to no activity on 2024/01/14 07:58
upstream KCSAN: data-race in aio_read_events / iocb_put (6) fs 6 1 1204d 1204d 0/29 auto-obsoleted due to no activity on 2023/01/02 10:55
upstream KCSAN: data-race in aio_read_events / iocb_put (2) fs 6 1 1717d 1717d 0/29 auto-closed as invalid on 2021/08/02 19:13
upstream KCSAN: data-race in aio_read_events / iocb_put (3) fs 6 2 1623d 1629d 0/29 auto-closed as invalid on 2021/11/04 18:41
upstream KCSAN: data-race in aio_read_events / iocb_put (4) fs 6 1 1454d 1454d 0/29 auto-closed as invalid on 2022/04/23 01:57
upstream KCSAN: data-race in aio_read_events / iocb_put fs 6 2 1756d 1780d 0/29 auto-closed as invalid on 2021/06/24 15:51
upstream KCSAN: data-race in aio_read_events / iocb_put (8) fs 6 1 907d 907d 0/29 auto-obsoleted due to no activity on 2023/10/21 20:27

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

write to 0xffff88813ae2800c of 4 bytes by task 10185 on cpu 1:
 aio_complete fs/aio.c:1162 [inline]
 iocb_put+0x18c/0x680 fs/aio.c:1209
 io_submit_one+0xbcb/0x1350 fs/aio.c:2056
 __do_sys_io_submit fs/aio.c:2112 [inline]
 __se_sys_io_submit+0xfb/0x280 fs/aio.c:2082
 __x64_sys_io_submit+0x43/0x50 fs/aio.c:2082
 x64_sys_call+0x19d5/0x3020 arch/x86/include/generated/asm/syscalls_64.h:210
 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 0xffff88813ae2800c of 4 bytes by task 10186 on cpu 0:
 aio_read_events_ring fs/aio.c:1238 [inline]
 aio_read_events+0xb2/0x400 fs/aio.c:1298
 read_events fs/aio.c:1334 [inline]
 do_io_getevents+0x11b/0x450 fs/aio.c:2230
 __do_sys_io_getevents fs/aio.c:2263 [inline]
 __se_sys_io_getevents fs/aio.c:2251 [inline]
 __x64_sys_io_getevents+0xca/0x190 fs/aio.c:2251
 x64_sys_call+0x2cfe/0x3020 arch/x86/include/generated/asm/syscalls_64.h:209
 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: 0x00000003 -> 0x00000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10186 Comm: syz.7.1697 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/12 14:44 upstream c22e26bd0906 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in aio_read_events / iocb_put
2026/01/20 09:17 upstream 24d479d26b25 572effc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in aio_read_events / iocb_put
* Struck through repros no longer work on HEAD.