[moderation] [io-uring?] KCSAN: data-race in io_sq_thread / io_sq_thread_stop

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bcde95ce32b6 Merge tag 'devicetree-fixes-for-6.13-1' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17c60adf980000
kernel config: https://syzkaller.appspot.com/x/.config?x=67aa69407438e9cf
dashboard link: https://syzkaller.appspot.com/bug?extid=5988142e8a69a67b1418
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [asml.s...@gmail.com ax...@kernel.dk io-u...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/858451b6ea4a/disk-bcde95ce.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/57191e69157f/vmlinux-bcde95ce.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c0d44f42d735/bzImage-bcde95ce.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+598814...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in io_sq_thread / io_sq_thread_stop

write to 0xffff888102ce0878 of 8 bytes by task 7248 on cpu 1:
io_sq_thread+0xe68/0x10b0 io_uring/sqpoll.c:378
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff888102ce0878 of 8 bytes by task 1128 on cpu 0:
io_sq_thread_stop+0x1d/0xd0 io_uring/sqpoll.c:60
io_put_sq_data io_uring/sqpoll.c:76 [inline]
io_sq_thread_finish+0x252/0x2d0 io_uring/sqpoll.c:101
io_ring_ctx_free+0x1a/0x710 io_uring/io_uring.c:2727
io_ring_exit_work+0x4d5/0x500 io_uring/io_uring.c:2968
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0xffff888102f06300 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 1128 Comm: kworker/u8:12 Not tainted 6.13.0-rc3-syzkaller-00301-gbcde95ce32b6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: iou_exit io_ring_exit_work
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.