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=-13.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D84DCC352A3 for ; Mon, 10 Feb 2020 14:18:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACE7820714 for ; Mon, 10 Feb 2020 14:18:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="DrXdjuDH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728308AbgBJOSa (ORCPT ); Mon, 10 Feb 2020 09:18:30 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:33398 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727434AbgBJOS3 (ORCPT ); Mon, 10 Feb 2020 09:18:29 -0500 Received: from pendragon.ideasonboard.com (236.249-200-80.adsl-static.isp.belgacom.be [80.200.249.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 19225808; Mon, 10 Feb 2020 15:18:27 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1581344307; bh=H4Lfal80navRWE85ASZ6DxsNe+fUpwm6ausCv/QBWPw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DrXdjuDHMXMJxWcqrJ7jjPNiBDU5qKbGqE9149OTyA5Tr3w3ON3+26zIMDdLiNmZT HmS1bPC5tnrbvs06RvXTMGbX8dqeGLUYGZfVFQ2vGTwAEtd/gKCaTHV0p2YqXqiLtc w6bRmLmy2WyhoYt2LV9OTckoezYPOjuMqKHnJDYQ= Date: Mon, 10 Feb 2020 16:18:12 +0200 From: Laurent Pinchart To: Oliver Neukum Cc: syzbot , andreyknvl@google.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-usb@vger.kernel.org, mchehab@kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: KASAN: use-after-free Read in uvc_probe Message-ID: <20200210141812.GB4727@pendragon.ideasonboard.com> References: <000000000000780999059c048dfc@google.com> <1581344006.26936.7.camel@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1581344006.26936.7.camel@suse.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Oliver, Thank you for the patch. On Mon, Feb 10, 2020 at 03:13:26PM +0100, Oliver Neukum wrote: > Am Montag, den 13.01.2020, 04:24 -0800 schrieb syzbot: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: ae179410 usb: gadget: add raw-gadget interface > > git tree: https://github.com/google/kasan.git usb-fuzzer > > console output: https://syzkaller.appspot.com/x/log.txt?x=132223fee00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=ad1d751a3a72ae57 > > dashboard link: https://syzkaller.appspot.com/bug?extid=9a48339b077c5a80b869 > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16857325e00000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=142e069ee00000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+9a48339b077c5a80b869@syzkaller.appspotmail.com > > > > usb 1-1: New USB device found, idVendor=0bd3, idProduct=0555, > > bcdDevice=69.6a > > usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 > > usb 1-1: config 0 descriptor?? > > usb 1-1: string descriptor 0 read error: -71 > > uvcvideo: Found UVC 0.00 device (0bd3:0555) > > ================================================================== > > BUG: KASAN: use-after-free in uvc_register_terms > > drivers/media/usb/uvc/uvc_driver.c:2038 [inline] > > BUG: KASAN: use-after-free in uvc_register_chains > > drivers/media/usb/uvc/uvc_driver.c:2070 [inline] > > BUG: KASAN: use-after-free in uvc_probe.cold+0x2193/0x29de > > drivers/media/usb/uvc/uvc_driver.c:2201 > > Read of size 2 at addr ffff8881d4f1bc2e by task kworker/1:2/94 > > #syz test: https://github.com/google/kasan.git ae179410 > > From db844641a5e30f3cfc0ce9cde156b3cc356b6c0c Mon Sep 17 00:00:00 2001 > From: Oliver Neukum > Date: Mon, 10 Feb 2020 15:10:36 +0100 > Subject: [PATCH] UVC: deal with unnamed streams > > The pointer can be NULL > > Signed-off-by: Oliver Neukum > --- > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > index 99883550375e..26558a89f2fe 100644 > --- a/drivers/media/usb/uvc/uvc_driver.c > +++ b/drivers/media/usb/uvc/uvc_driver.c > @@ -2069,7 +2069,8 @@ static int uvc_register_terms(struct uvc_device *dev, > stream = uvc_stream_by_id(dev, term->id); > if (stream == NULL) { > uvc_printk(KERN_INFO, "No streaming interface found " > - "for terminal %u.", term->id); > + "for terminal %u.", > + term->id ? term->id : "(Unnamed)"); Have you tried compiling this ? > continue; > } > -- Regards, Laurent Pinchart