Re: crash by cdc_acm driver in kernels 4.8-rc1/5

From: Oliver Neukum
Date: Thu Sep 08 2016 - 08:26:00 EST


On Thu, 2016-09-08 at 13:58 +0200, Wim Osterholt wrote:
> L.S.
>
> up to vanilla kernel 4.7.3 I've seen no problems.
> On two different dekstops running vanilla kernel-4.8 I can force a
> crash by
> inserting an USB-modem that requires module cdc_acm.ko .
> (Strangely enough that doesn't happen on my laptop.)
>
> The moment that cdc_acm loads (manually or automatically - the
> hardware needs
> to be present) a kernel oops occurs.
> The system remains responsive for a while, but a reboot is necessairy.
> If you try a neat shutdown, the system will hang forever after
> 'remounting fs
> read-only'. You'll need a power-down.
>
> The oops tells things that I didn't all write down, but it says
> null pointer dereference at 00000246

That is the important part. I am sorry, but without the oops
nobody can help you. Please capture it

dmesg > /root/oops.txt

and report it.

Regards
Oliver