Re: general protection fault in io_poll_double_wake

From: Jens Axboe
Date: Sat Aug 15 2020 - 18:02:24 EST


On 8/15/20 10:00 AM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 7fca4dee Merge tag 'powerpc-5.9-2' of git://git.kernel.org..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1264d116900000
> kernel config: https://syzkaller.appspot.com/x/.config?x=21f0d1d2df6d5fc
> dashboard link: https://syzkaller.appspot.com/bug?extid=7f617d4a9369028b8a2c
> compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10f211d2900000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1721b0ce900000
>
> The issue was bisected to:
>
> commit 18bceab101adde8f38de76016bc77f3f25cf22f4
> Author: Jens Axboe <axboe@xxxxxxxxx>
> Date: Fri May 15 17:56:54 2020 +0000
>
> io_uring: allow POLL_ADD with double poll_wait() users

I can reproduce this, I'll fix it up. Thanks!

--
Jens Axboe