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Subject: Re: general protection fault in io_poll_double_wake
To:     syzbot <syzbot+7f617d4a9369028b8a2c@syzkaller.appspotmail.com>,
        io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        viro@zeniv.linux.org.uk
References: <00000000000018f60505aced798e@google.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <fb1fe8ff-5c79-a020-f6ea-a28f974bde6b@kernel.dk>
Date:   Sat, 15 Aug 2020 11:16:17 -0700
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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@kernel.dk>
> 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