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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 27B29C54FCB for ; Thu, 23 Apr 2020 23:07:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B9BC20780 for ; Thu, 23 Apr 2020 23:07:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728907AbgDWXHf (ORCPT ); Thu, 23 Apr 2020 19:07:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51126 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728681AbgDWXHC (ORCPT ); Thu, 23 Apr 2020 19:07:02 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jRkvl-0004yI-T7; Fri, 24 Apr 2020 00:06:54 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jRkvk-00E748-IY; Fri, 24 Apr 2020 00:06:52 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , linux-can@vger.kernel.org, security@kernel.org, "Kees Cook" , davem@davemloft.net, netdev@vger.kernel.org, wg@grandegger.com, "Richard Palethorpe" , mkl@pengutronix.de Date: Fri, 24 Apr 2020 00:07:52 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 245/245] slcan: Don't transmit uninitialized stack data in padding In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.83-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Richard Palethorpe commit b9258a2cece4ec1f020715fe3554bc2e360f6264 upstream. struct can_frame contains some padding which is not explicitly zeroed in slc_bump. This uninitialized data will then be transmitted if the stack initialization hardening feature is not enabled (CONFIG_INIT_STACK_ALL). This commit just zeroes the whole struct including the padding. Signed-off-by: Richard Palethorpe Fixes: a1044e36e457 ("can: add slcan driver for serial/USB-serial CAN adapters") Reviewed-by: Kees Cook Cc: linux-can@vger.kernel.org Cc: netdev@vger.kernel.org Cc: security@kernel.org Cc: wg@grandegger.com Cc: mkl@pengutronix.de Cc: davem@davemloft.net Acked-by: Marc Kleine-Budde Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/net/can/slcan.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -150,7 +150,7 @@ static void slc_bump(struct slcan *sl) u32 tmpid; char *cmd = sl->rbuff; - cf.can_id = 0; + memset(&cf, 0, sizeof(cf)); switch (*cmd) { case 'r': @@ -189,8 +189,6 @@ static void slc_bump(struct slcan *sl) else return; - *(u64 *) (&cf.data) = 0; /* clear payload */ - /* RTR frames may have a dlc > 0 but they never have any data bytes */ if (!(cf.can_id & CAN_RTR_FLAG)) { for (i = 0; i < cf.can_dlc; i++) {