Re: Oops in 4.6-rc2: NULL pointer dereference in cdc-acm

From: Greg KH
Date: Thu Apr 07 2016 - 10:47:13 EST


On Thu, Apr 07, 2016 at 08:59:38AM +0200, Oliver Neukum wrote:
> On Wed, 2016-04-06 at 22:48 +0200, Gabriele Mazzotta wrote:
> > Hi,
> >
> > I'm getting a kernel oops when I plug some smartphone via USB to my
> > laptop, which is currently running the v4.6-rc2.
> >
> > The problem seems to be caused by a81cf9799ad7 ("cdc-acm: implement
> > put_char() and flush_chars()").
> >
> > A simple NULL pointer check prevents the crash, but since I have no
> > use of cdc-acm and I didn't read the code, I don't know if some other
> > changes are required.
> >
> > Here below you can find the change I did to prevent the crash and
> > the dmesg showing the problem.
>
> Hi,
>
> thank you for reporting this. You are the second one to report it.
> I send a fix upstream last week.
> Greg, can we merge this for the next rc? People are hitting this
> bug.

Yes, will be sent this week, sorry for the delay.

greg k-h