[syzbot] upstream test error: WARNING in __do_kernel_fault

[Will Deacon]

On Fri, Sep 17, 2021 at 10:20:40AM +0200, Dmitry Vyukov wrote:
> On Mon, 6 Sept 2021 at 11:55, syzbot
> <syzbot+e6bda7e03e329ed0b1db at syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    f1583cb1be35 Merge tag 'linux-kselftest-next-5.15-rc1' of ..
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=17756315300000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=5fe535c85e8d7384
> > dashboard link: https://syzkaller.appspot.com/bug?extid=e6bda7e03e329ed0b1db
> > compiler:       aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
> > userspace arch: arm64
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+e6bda7e03e329ed0b1db at syzkaller.appspotmail.com
> 
> +Will, you added this WARNING in 42f91093b04333.
> This now crashes periodically on syzbot.

I'm still inclined to chalk this one down to a QEMU bug. We're not seeing it
anywhere else, and last time you looked at it I seem to remember that it
depended upon QEMU configuration [1].

Will

[1] https://lore.kernel.org/all/CAAeHK+wDz8aSLyjq1b=q3+HG9aJXxwYR6+gN_fTttMN5osM5gg@mail.gmail.com/