Re: [syzbot] general protection fault in gadget_setup

[Dmitry Vyukov]

On Tue, Apr 13, 2021 at 6:57 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Apr 13, 2021 at 06:47:47PM +0200, Dmitry Vyukov wrote:
> > On Tue, Apr 13, 2021 at 6:13 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> > > Hopefully this patch will make the race a lot more likely to occur.  Is
> > > there any way to tell syzkaller to test it, despite the fact that
> > > syzkaller doesn't think it has a reproducer for this issue?
> >
> > If there is no reproducer the only way syzbot can test it is if it's
> > in linux-next under CONFIG_DEBUG_AID_FOR_SYZBOT:
> > http://bit.do/syzbot#no-custom-patches
>
> There _is_ a theoretical reproducer: the test that provoked syzkaller's
> original bug report.  But syzkaller doesn't realize that it is (or may
> be) a reproducer.
>
> It ought to be possible to ask syzkaller to run a particular test that
> it has done before, with a patch applied -- and without having to add
> anything to linux-next.

Yes, this is possible:
http://bit.do/syzbot#syzkaller-reproducers

The log of tests executed before the crash is available under the
"console output" link:
console output: https://syzkaller.appspot.com/x/log.txt?x=124adbf6d00000
And this log can be replayed using syz-execprog utility.