Re: WARNING in request_end

From: Miklos Szeredi
Date: Mon Sep 24 2018 - 10:45:03 EST


On Mon, Sep 24, 2018 at 2:29 PM, syzbot
<syzbot+ef054c4d3f64cd7f7cec@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 6bf4ca7fbc85 Linux 4.19-rc5
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=159149c6400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=22a62640793a83c9
> dashboard link: https://syzkaller.appspot.com/bug?extid=ef054c4d3f64cd7f7cec
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+ef054c4d3f64cd7f7cec@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> WARNING: CPU: 0 PID: 9445 at fs/fuse/dev.c:390 request_end+0x82e/0xaa0

And there we have the bug likely caused by the set_bit(FR_SENT, ...)
not being inside the fpq->lock-ed region.

So that needs to be fixed anyway, apparently.

Thanks,
Miklos