Re: general protection fault in io_poll_double_wake

[Jens Axboe]

On 8/15/20 11:16 AM, Jens Axboe wrote:
> 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!

This should fix it: