On 2/9/21 7:57 PM, Pavel Begunkov wrote: > On 10/02/2021 00:54, syzbot wrote: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: dd86e7fa Merge tag 'pci-v5.11-fixes-2' of git://git.kernel.. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=13e43f90d00000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=e83e68d0a6aba5f6 >> dashboard link: https://syzkaller.appspot.com/bug?extid=695b03d82fa8e4901b06 >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1490f0d4d00000 >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17aedf1cd00000 >> >> IMPORTANT: if you fix the issue, please add the following tag to the commit: >> Reported-by: syzbot+695b03d82fa8e4901b06@xxxxxxxxxxxxxxxxxxxxxxxxx > > It looks like SQPOLL. I wonder if that's due to parked SQPOLL task that > won't be able to do task_work run, and so reap poll-cancelled requests > killed by io_put_deferred(). > > I'll test it out tomorrow. It is indeed SQPOLL. From a quick look, it's doing a POLL_ADD on the ring fd itself. -- Jens Axboe