linux-kernel - [syzbot] [io-uring?] KCSAN: data-race in io_sq_thread / io_sq_thread

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Message-ID: <00000000000065552a061f8cb396@google.com>
Date: Tue, 13 Aug 2024 01:50:25 -0700
From: syzbot <syzbot+2b946a3fd80caf971b21@...kaller.appspotmail.com>
To: asml.silence@...il.com, axboe@...nel.dk, io-uring@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [io-uring?] KCSAN: data-race in io_sq_thread /
 io_sq_thread_park (9)

Hello,

syzbot found the following issue on:

HEAD commit:    6a0e38264012 Merge tag 'for-6.11-rc2-tag' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1019759d980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cb57e6ebf675f9d2
dashboard link: https://syzkaller.appspot.com/bug?extid=2b946a3fd80caf971b21
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/753a842a966b/disk-6a0e3826.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e12e23519777/vmlinux-6a0e3826.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bce0584a8cb4/bzImage-6a0e3826.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2b946a3fd80caf971b21@...kaller.appspotmail.com

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

write to 0xffff888111459638 of 8 bytes by task 10761 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 0xffff888111459638 of 8 bytes by task 10329 on cpu 0:
 io_sq_thread_park+0x1b/0x80 io_uring/sqpoll.c:47
 io_ring_exit_work+0x197/0x500 io_uring/io_uring.c:2786
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x526/0x700 kernel/workqueue.c:3390
 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: 0xffff8881223d0000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10329 Comm: kworker/u8:8 Not tainted 6.11.0-rc2-syzkaller-00027-g6a0e38264012 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: iou_exit io_ring_exit_work
==================================================================


---
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