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=-2.3 required=3.0 tests=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 1406EC433FF for ; Tue, 13 Aug 2019 08:15:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E577C206C1 for ; Tue, 13 Aug 2019 08:15:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727720AbfHMIO7 (ORCPT ); Tue, 13 Aug 2019 04:14:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:42204 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725981AbfHMIO7 (ORCPT ); Tue, 13 Aug 2019 04:14:59 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 5AA8AAC10; Tue, 13 Aug 2019 08:14:57 +0000 (UTC) Message-ID: <1565684094.7043.3.camel@suse.com> Subject: Re: WARNING in usbhid_raw_request/usb_submit_urb From: Oliver Neukum To: Hillf Danton , syzbot Cc: gustavo@embeddedor.com, Jiri Slaby , andreyknvl@google.com, syzkaller-bugs@googlegroups.com, gregkh@linuxfoundation.org, stern@rowland.harvard.edu, Jiri Kosina , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Date: Tue, 13 Aug 2019 10:14:54 +0200 In-Reply-To: <20190813042649.888-1-hdanton@sina.com> References: <20190813042649.888-1-hdanton@sina.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 Dienstag, den 13.08.2019, 12:26 +0800 schrieb Hillf Danton: > [respin with the mess in Cc list cleaned up] > Followup of commit e3e14de50dff ("HID: fix start/stop cycle in usbhid driver") > > --- a/drivers/hid/usbhid/hid-core.c > +++ b/drivers/hid/usbhid/hid-core.c > @@ -1214,6 +1214,8 @@ static void usbhid_stop(struct hid_devic > > hid->claimed = 0; > > + if (!usbhid->urbin) /* freeing buffers only once */ > + return; > usb_free_urb(usbhid->urbin); > usb_free_urb(usbhid->urbctrl); > usb_free_urb(usbhid->urbout); This looks rather suspicious. Why is stop() called multiple times? Do we have a refcounting issue? If not, what controls locking? Regards Oliver