From patchwork Sat Jun 19 22:01:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 464229 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 A3AABC49EA5 for ; Sat, 19 Jun 2021 22:01:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C8AE601FC for ; Sat, 19 Jun 2021 22:01:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230316AbhFSWDr (ORCPT ); Sat, 19 Jun 2021 18:03:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230175AbhFSWDj (ORCPT ); Sat, 19 Jun 2021 18:03:39 -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 B0A56C061756 for ; Sat, 19 Jun 2021 15:01:27 -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 1luj1q-0005YE-5N for netdev@vger.kernel.org; Sun, 20 Jun 2021 00:01:26 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 6210063F817 for ; Sat, 19 Jun 2021 22:01:23 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (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) by bjornoya.blackshift.org (Postfix) with ESMTPS id AAC6663F7EA; Sat, 19 Jun 2021 22:01:19 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 1f9ffb67; Sat, 19 Jun 2021 22:01:18 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Pavel Skripkin , linux-stable , Marc Kleine-Budde Subject: [net 5/5] net: can: ems_usb: fix use-after-free in ems_usb_disconnect() Date: Sun, 20 Jun 2021 00:01:15 +0200 Message-Id: <20210619220115.2830761-6-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210619220115.2830761-1-mkl@pengutronix.de> References: <20210619220115.2830761-1-mkl@pengutronix.de> MIME-Version: 1.0 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: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Pavel Skripkin In ems_usb_disconnect() dev pointer, which is netdev private data, is used after free_candev() call: | if (dev) { | unregister_netdev(dev->netdev); | free_candev(dev->netdev); | | unlink_all_urbs(dev); | | usb_free_urb(dev->intr_urb); | | kfree(dev->intr_in_buffer); | kfree(dev->tx_msg_buffer); | } Fix it by simply moving free_candev() at the end of the block. Fail log: | BUG: KASAN: use-after-free in ems_usb_disconnect | Read of size 8 at addr ffff88804e041008 by task kworker/1:2/2895 | | 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/can/usb/ems_usb.c:1058) Fixes: 702171adeed3 ("ems_usb: Added support for EMS CPC-USB/ARM7 CAN/USB interface") Link: https://lore.kernel.org/r/20210617185130.5834-1-paskripkin@gmail.com Cc: linux-stable Signed-off-by: Pavel Skripkin Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/ems_usb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c index 5af69787d9d5..0a37af4a3fa4 100644 --- a/drivers/net/can/usb/ems_usb.c +++ b/drivers/net/can/usb/ems_usb.c @@ -1053,7 +1053,6 @@ static void ems_usb_disconnect(struct usb_interface *intf) if (dev) { unregister_netdev(dev->netdev); - free_candev(dev->netdev); unlink_all_urbs(dev); @@ -1061,6 +1060,8 @@ static void ems_usb_disconnect(struct usb_interface *intf) kfree(dev->intr_in_buffer); kfree(dev->tx_msg_buffer); + + free_candev(dev->netdev); } }