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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 341BFC282DD for ; Thu, 9 Jan 2020 16:46:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1244C2064C for ; Thu, 9 Jan 2020 16:46:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387813AbgAIQqJ (ORCPT ); Thu, 9 Jan 2020 11:46:09 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:36172 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1731399AbgAIQqI (ORCPT ); Thu, 9 Jan 2020 11:46:08 -0500 Received: (qmail 2234 invoked by uid 2102); 9 Jan 2020 11:46:07 -0500 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 9 Jan 2020 11:46:07 -0500 Date: Thu, 9 Jan 2020 11:46:07 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: syzbot cc: andreyknvl@google.com, , , , , , Subject: Re: WARNING in usbhid_raw_request/usb_submit_urb (2) In-Reply-To: <0000000000001b53f8059ba5431a@google.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 8 Jan 2020, syzbot wrote: > Hello, > > syzbot has tested the proposed patch and the reproducer did not trigger > crash: > > Reported-and-tested-by: > syzbot+10e5f68920f13587ab12@syzkaller.appspotmail.com > > Tested on: > > commit: ecdf2214 usb: gadget: add raw-gadget interface > git tree: https://github.com/google/kasan.git > kernel config: https://syzkaller.appspot.com/x/.config?x=b06a019075333661 > dashboard link: https://syzkaller.appspot.com/bug?extid=10e5f68920f13587ab12 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > patch: https://syzkaller.appspot.com/x/patch.diff?x=1583963ee00000 > > Note: testing is done by a robot and is best-effort only. I'm at a loss for a way to track this down any farther. The difference between this patch and the previous was very small and almost entirely confined to actions that take place _after_ the bug condition has been detected. If this is indeed caused by a race, it would be nice to know that the two racing threads are doing. One of them we can see in the log output (it's calling usb_control_msg) but the other is a mystery. Alan Stern