[syzbot] WARNING in io_req_complete_failed

[syzbot] WARNING in io_req_complete_failed

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    c35bd4e42885 Add linux-next specific files for 20221124
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=130f4e73880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=11e19c740a0b2926
dashboard link: https://syzkaller.appspot.com/bug?extid=bc54516b728ef2a08d76
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10082015880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11107a05880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/968fee464d14/disk-c35bd4e4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4f46fe801b5b/vmlinux-c35bd4e4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c2cdf8fb264e/bzImage-c35bd4e4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bc54516b728ef2a08d76@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 151 at io_uring/io_uring.c:872 io_req_complete_failed+0x223/0x280 io_uring/io_uring.c:872
Modules linked in:
CPU: 0 PID: 151 Comm: kworker/0:2 Not tainted 6.1.0-rc6-next-20221124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: events io_fallback_req_func
RIP: 0010:io_req_complete_failed+0x223/0x280 io_uring/io_uring.c:872
Code: 58 be ff ff ff ff 48 8d b8 a8 00 00 00 e8 a5 24 03 06 31 ff 89 c3 89 c6 e8 3a 43 7d fd 85 db 0f 85 66 fe ff ff e8 7d 46 7d fd <0f> 0b e9 5a fe ff ff e8 91 66 cb fd e9 06 fe ff ff e8 67 67 cb fd
RSP: 0018:ffffc90002e9fc28 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801a690000 RSI: ffffffff84038513 RDI: 0000000000000005
RBP: ffff88807e9aa3c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 1ffffffff21621e8 R12: 0000000000000016
R13: 00000000ffffff83 R14: dffffc0000000000 R15: ffffffffffffff78
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe6e758a01d CR3: 000000000c48e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 io_apoll_task_func+0x14d/0x170 io_uring/poll.c:319
 io_fallback_req_func+0xfd/0x1b2 io_uring/io_uring.c:250
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>


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Re: [syzbot] WARNING in io_req_complete_failed

[Jens Axboe]

#syz fix: io_uring: always lock in io_apoll_task_func

-- 
Jens Axboe