From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757456AbcIHMZ5 (ORCPT ); Thu, 8 Sep 2016 08:25:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:50428 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751563AbcIHMZ4 (ORCPT ); Thu, 8 Sep 2016 08:25:56 -0400 Message-ID: <1473337238.32073.2.camel@suse.com> Subject: Re: crash by cdc_acm driver in kernels 4.8-rc1/5 From: Oliver Neukum To: wim@djo.tudelft.nl Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Date: Thu, 08 Sep 2016 14:20:38 +0200 In-Reply-To: <20160908115803.GA28274@djo.tudelft.nl> References: <20160908115803.GA28274@djo.tudelft.nl> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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