Re: general protection fault in usb_set_interface

[Andrey Konovalov]

On Wed, Sep 18, 2019 at 8:57 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, 17 Sep 2019, syzbot wrote:
>
> > Hello,
> >
> > syzbot has tested the proposed patch but the reproducer still triggered
> > crash:
> > WARNING in sysfs_remove_group
> >
> > ------------[ cut here ]------------
> > sysfs group 'power' not found for kobject 'radio0'
>
> Andrey:
>
> Is there any way to tell syzbot to run the reproducer but with only one
> device instance (that is, only one dummy-hcd bus)?
>
> Or can you a new, modified reproducer that will do this?

AFAIU there two bugs here and you've fixed the first one, but the
second one gets triggered.

I think the second one got reported separately here:

https://syzkaller.appspot.com/bug?extid=5b9bba68c833c84a1135

That one has a reproducer with a single dummy-hcd, so you can try
running your debugging patch against that report.

I'll see if I can run it manually in the meantime.