From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F312C433E4 for ; Tue, 21 Jul 2020 08:01:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48C7C20709 for ; Tue, 21 Jul 2020 08:01:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728642AbgGUIBk (ORCPT ); Tue, 21 Jul 2020 04:01:40 -0400 Received: from mx2.suse.de ([195.135.220.15]:59328 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728077AbgGUIBk (ORCPT ); Tue, 21 Jul 2020 04:01:40 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 31A34AFCD; Tue, 21 Jul 2020 08:01:46 +0000 (UTC) Message-ID: <1595318497.29149.3.camel@suse.de> Subject: Re: System crash/lockup after plugging CDC ACM device From: Oliver Neukum To: David Guillen Fandos , Greg KH Cc: linux-usb@vger.kernel.org Date: Tue, 21 Jul 2020 10:01:37 +0200 In-Reply-To: References: <9778f9b8a8604e2c13979ea6909678c23cd286cb.camel@davidgf.net> <20200715093029.GB2759174@kroah.com> <867592c41350b09a0cb67e9a3924f8a2f758d79a.camel@davidgf.net> <20200715105034.GB2880893@kroah.com> <956ec3169eec6b121339ed6c1aedd0f7ca08db43.camel@davidgf.net> <20200715111210.GA2892661@kroah.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Am Mittwoch, den 15.07.2020, 13:20 +0200 schrieb David Guillen Fandos: > Shouldn't the kernel be resilient to such devices? I've developed quite > a few USB devices in the past and I've never ran into things like this > on Linux Yes. Unfortunately we do not know which module is crashing here. It may be as simple as CDC-ACM retrying without a delay or giving up. Or this is in usbcore. Could you initially try without CDC-ACM, so we can narrow this down? And tehn we can try with dynamic debugging or thought what can be done. And thank you for identifying the root cause for the malfunction. Yet you are clearly right that even such a device should not crash the kernel. Regards Oliver