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=-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,URIBL_BLOCKED,USER_AGENT_GIT 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 DDCD9C48BE6 for ; Wed, 16 Jun 2021 11:02:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5C6C61075 for ; Wed, 16 Jun 2021 11:02:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232306AbhFPLEn (ORCPT ); Wed, 16 Jun 2021 07:04:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232586AbhFPLEO (ORCPT ); Wed, 16 Jun 2021 07:04:14 -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 CB869C06121D for ; Wed, 16 Jun 2021 04:02:02 -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 1ltTJ3-0007ow-6T for linux-can@vger.kernel.org; Wed, 16 Jun 2021 13:02:01 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 66FEB63D2AD for ; Wed, 16 Jun 2021 11:01:58 +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 1394863D292; Wed, 16 Jun 2021 11:01:55 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 688c17f5; Wed, 16 Jun 2021 11:01:54 +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, Norbert Slusarek , linux-stable , Oliver Hartkopp , Marc Kleine-Budde Subject: [net 3/4] can: bcm: fix infoleak in struct bcm_msg_head Date: Wed, 16 Jun 2021 13:01:51 +0200 Message-Id: <20210616110152.2456765-4-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210616110152.2456765-1-mkl@pengutronix.de> References: <20210616110152.2456765-1-mkl@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 From: Norbert Slusarek On 64-bit systems, struct bcm_msg_head has an added padding of 4 bytes between struct members count and ival1. Even though all struct members are initialized, the 4-byte hole will contain data from the kernel stack. This patch zeroes out struct bcm_msg_head before usage, preventing infoleaks to userspace. Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol") Link: https://lore.kernel.org/r/trinity-7c1b2e82-e34f-4885-8060-2cd7a13769ce-1623532166177@3c-app-gmx-bs52 Cc: linux-stable Signed-off-by: Norbert Slusarek Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- net/can/bcm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/can/bcm.c b/net/can/bcm.c index f00176b2a6c3..f3e4d9528fa3 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -406,6 +406,7 @@ static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) if (!op->count && (op->flags & TX_COUNTEVT)) { /* create notification to user */ + memset(&msg_head, 0, sizeof(msg_head)); msg_head.opcode = TX_EXPIRED; msg_head.flags = op->flags; msg_head.count = op->count; @@ -443,6 +444,7 @@ static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data) /* this element is not throttled anymore */ data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV); + memset(&head, 0, sizeof(head)); head.opcode = RX_CHANGED; head.flags = op->flags; head.count = op->count; @@ -564,6 +566,7 @@ static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) } /* create notification to user */ + memset(&msg_head, 0, sizeof(msg_head)); msg_head.opcode = RX_TIMEOUT; msg_head.flags = op->flags; msg_head.count = op->count; -- 2.30.2