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 903EEC0650F for ; Mon, 5 Aug 2019 09:59:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DC31217D9 for ; Mon, 5 Aug 2019 09:59:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728215AbfHEJ7T (ORCPT ); Mon, 5 Aug 2019 05:59:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:57052 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727259AbfHEJ7S (ORCPT ); Mon, 5 Aug 2019 05:59:18 -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 3CB1FB624; Mon, 5 Aug 2019 09:59:17 +0000 (UTC) Message-ID: <1564998287.4248.5.camel@suse.com> Subject: Re: KASAN: use-after-free Read in usb_free_coherent From: Oliver Neukum To: Suzuki K Poulose , dtor@chromium.org, andreyknvl@google.com, syzkaller-bugs@googlegroups.com, robh@kernel.org, srinivas.kandagatla@linaro.org, gregkh@linuxfoundation.org, mans@mansr.com, mathias.payer@nebelwelt.net, stern@rowland.harvard.edu, syzbot+d1fedb1c1fdb07fca507@syzkaller.appspotmail.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Date: Mon, 05 Aug 2019 11:44:47 +0200 In-Reply-To: <8d2b9cb5-d32c-e24c-c973-a3a11a436dc6@arm.com> References: <0000000000003f86d8058f0bd671@google.com> <8d2b9cb5-d32c-e24c-c973-a3a11a436dc6@arm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Donnerstag, den 01.08.2019, 11:52 +0100 schrieb Suzuki K Poulose: > > Looks like the yurex_delete() drops the ref count on the dev->udev > way early in the function and then later tries to see if there > are any other buffers associated with it worth releasing. So, > I am guessing moving the usb_put_dev(), after we have finished > all that might solve the issue ? Hi, the fix looks good to me. Regards Oliver