[moderation] [io-uring?] KCSAN: data-race in io_sq_thread / io_uring_try_cancel_requests (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: de0a9f448633 Merge tag 'riscv-for-linus-6.10-rc6' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12044699980000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e87b541dc1fc960
dashboard link: https://syzkaller.appspot.com/bug?extid=6880371d15aebe0565d8
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/151385872b8c/disk-de0a9f44.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/43c635e97c12/vmlinux-de0a9f44.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4de143542d3a/bzImage-de0a9f44.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+688037...@syzkaller.appspotmail.com

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

write to 0xffff888110de4278 of 8 bytes by task 31731 on cpu 1:
io_sq_thread+0xdab/0xff0 io_uring/sqpoll.c:383
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 0xffff888110de4278 of 8 bytes by task 28 on cpu 0:
io_uring_try_cancel_requests+0x1c3/0x370 io_uring/io_uring.c:3016
io_ring_exit_work+0x148/0x500 io_uring/io_uring.c:2817
process_one_work kernel/workqueue.c:3248 [inline]
process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3329
worker_thread+0x526/0x720 kernel/workqueue.c:3409
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: 0xffff888108cd0000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 28 Comm: kworker/u8:1 Not tainted 6.10.0-rc5-syzkaller-00253-gde0a9f448633 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: iou_exit io_ring_exit_work
==================================================================


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