Re: KASAN: use-after-free Read in si470x_int_in_callback (2)

From: Oliver Neukum
Date: Fri Nov 22 2019 - 14:17:22 EST


Am Freitag, den 22.11.2019, 10:35 -0500 schrieb Alan Stern:
> On Fri, 22 Nov 2019, syzbot wrote:
>
> > Hello,
> >
> > syzbot has tested the proposed patch but the reproducer still triggered
> > crash:
> > INFO: rcu detected stall in dummy_timer
> >
> > radio-si470x 1-1:0.0: non-zero urb status (-71)
> > radio-si470x 4-1:0.0: non-zero urb status (-71)
> > radio-si470x 3-1:0.0: non-zero urb status (-71)
>
> Oliver:
>
> The reason for this stall is because the driver goes into a tight
> resubmit loop when the interrupt URB completes with an unrecognized
> error status. Instead, the driver should log an error message and
> avoid resubmitting. Error recovery can be done at a higher level.
>
> In other words, change the
>
> goto resubmit; /* Maybe we can recover. */
>
> line in the completion handler into a return.

I thought so, too. That is why I poisoned the URB. Am I dense?

Regards
Oliver