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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 53CE4C49EA4 for ; Fri, 18 Jun 2021 07:17:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 29A41613B4 for ; Fri, 18 Jun 2021 07:17:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233086AbhFRHTi (ORCPT ); Fri, 18 Jun 2021 03:19:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233083AbhFRHTg (ORCPT ); Fri, 18 Jun 2021 03:19:36 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC39FC061574 for ; Fri, 18 Jun 2021 00:17:27 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lu8km-0003gp-5p; Fri, 18 Jun 2021 09:17:24 +0200 Received: from pengutronix.de (unknown [IPv6:2a03:f580:87bc:d400:e7d0:b47e:7728:2b24]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id A8CA463EA3C; Fri, 18 Jun 2021 07:04:52 +0000 (UTC) Date: Fri, 18 Jun 2021 09:04:52 +0200 From: Marc Kleine-Budde To: Pavel Skripkin Cc: wg@grandegger.com, davem@davemloft.net, linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH] net: can: fix use-after-free in ems_usb_disconnect Message-ID: <20210618070452.cjt7f5hzlfikztwz@pengutronix.de> References: <20210617185130.5834-1-paskripkin@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="6tq7svrpdp6b2uth" Content-Disposition: inline In-Reply-To: <20210617185130.5834-1-paskripkin@gmail.com> X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org --6tq7svrpdp6b2uth Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 17.06.2021 21:51:30, Pavel Skripkin wrote: > In ems_usb_disconnect() dev pointer, which is > netdev private data, is used after free_candev() call: >=20 > if (dev) { > unregister_netdev(dev->netdev); > free_candev(dev->netdev); >=20 > unlink_all_urbs(dev); >=20 > usb_free_urb(dev->intr_urb); >=20 > kfree(dev->intr_in_buffer); > kfree(dev->tx_msg_buffer); > } >=20 > Fix it by simply moving free_candev() at the end of > the block. >=20 > Fail log: > BUG: KASAN: use-after-free in ems_usb_disconnect > Read of size 8 at addr ffff88804e041008 by task kworker/1:2/2895 >=20 > CPU: 1 PID: 2895 Comm: kworker/1:2 Not tainted 5.13.0-rc5+ #164 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0= -g155821a-rebuilt.opensuse.4 > Workqueue: usb_hub_wq hub_event > Call Trace: > dump_stack (lib/dump_stack.c:122) > print_address_description.constprop.0.cold (mm/kasan/report.c:234) > kasan_report.cold (mm/kasan/report.c:420 mm/kasan/report.c:436) > ems_usb_disconnect (drivers/net/can/usb/ems_usb.c:683 drivers/net/ca= n/usb/ems_usb.c:1058) >=20 > Fixes: 702171adeed3 ("ems_usb: Added support for EMS CPC-USB/ARM7 CAN/USB= interface") > Signed-off-by: Pavel Skripkin Applied to linux-can/testing and added stable on Cc. Thanks, Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | --6tq7svrpdp6b2uth Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEK3kIWJt9yTYMP3ehqclaivrt76kFAmDMRZEACgkQqclaivrt 76mnqgf/aSKQviylfEMXNmblnBD4eGq3CMjiugvH+K4jof1OJ72ztvdUzP2DAfd/ 9CA0EE0UWEVpqhcUteGMMgM7F0+AqJF4PvgqiR5YT2qqnWg40xDcC2+NtdRYNBqt fQt+mzbXNj5J39v8l8FJGPo5Ip7E561khpGG9jA5BFgIT70jegTdNPho+uUV+CKV 1co2LUuDCPtnN/GZHOI3bLflWqr2p1V60RimGZK9QbOLYuf5ZynHkB4+GrwVO+MV Sryao3eO/JR06Ty6vo4RVh0SqWOFx549SGsl+O9pn7W5U4Sw+5eklu5UVW6OyL52 pWNIVhvfae9qHdITE3ZftnG0OPd1gQ== =n50B -----END PGP SIGNATURE----- --6tq7svrpdp6b2uth--