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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 D0567C2D0E4 for ; Thu, 12 Nov 2020 19:23:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8684721D7F for ; Thu, 12 Nov 2020 19:23:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726743AbgKLTXD (ORCPT ); Thu, 12 Nov 2020 14:23:03 -0500 Received: from netrider.rowland.org ([192.131.102.5]:33539 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726697AbgKLTXD (ORCPT ); Thu, 12 Nov 2020 14:23:03 -0500 Received: (qmail 287939 invoked by uid 1000); 12 Nov 2020 14:23:02 -0500 Date: Thu, 12 Nov 2020 14:23:02 -0500 From: Alan Stern To: John Boero Cc: Greg Kroah-Hartman , Felipe Balbi , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: core: Null deref in kernel with USB webcams. Message-ID: <20201112192302.GA287229@rowland.harvard.edu> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 12, 2020 at 05:13:30PM +0000, John Boero wrote: > Sorry header was generated by git email and I should have > paid closer attention to it before sending. > Long time listener, first time caller. > > Yes the patch is backwards sorry. Testing alt proposal from > stern@rowland.harvard.edu. It may be a buggy driver > but it would be nice if a buggy driver couldn't bring down > the entire usb core. lsusb hangs until reboot or reset of usb. > > It seems to behave fine on first use. Run Zoom or cheese > works fine first time. Subsequent runs, no device found > and usb is crashed with trace in dmesg. The whole point of asking you to try out that change was to see the trace in dmesg. What does it say? Alan Stern