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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 429BCC48BC2 for ; Mon, 21 Jun 2021 16:19:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 303DC61206 for ; Mon, 21 Jun 2021 16:19:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231552AbhFUQWK (ORCPT ); Mon, 21 Jun 2021 12:22:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:41976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231483AbhFUQVB (ORCPT ); Mon, 21 Jun 2021 12:21:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B7A4D6115B; Mon, 21 Jun 2021 16:18:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1624292326; bh=1x1hRAZ6Pi+CYrRjBq9UTSxGmEdKMGhQ4ei0K8P946A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XGMFpOSRv8TH8lu+ICCeoK2f4x8Gl9MRMUo+MjeEJr5NBPcaWFesFNSz2X8meXiq9 +bDR2EjrtI2nNxw43Z5++0F4O6D3LM68jHVvgNJb3rE6r8+ZEX/GfvwJ87d0xrH+es 81eQVpCD5R9Gz4p8pYX0g88SwIKWzUrPbPm0tLuk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Norbert Slusarek , Oliver Hartkopp , Marc Kleine-Budde Subject: [PATCH 5.4 50/90] can: bcm: fix infoleak in struct bcm_msg_head Date: Mon, 21 Jun 2021 18:15:25 +0200 Message-Id: <20210621154905.834965762@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210621154904.159672728@linuxfoundation.org> References: <20210621154904.159672728@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Norbert Slusarek commit 5e87ddbe3942e27e939bdc02deb8579b0cbd8ecc upstream. 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 Signed-off-by: Greg Kroah-Hartman --- net/can/bcm.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -404,6 +404,7 @@ static enum hrtimer_restart bcm_tx_timeo 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; @@ -441,6 +442,7 @@ static void bcm_rx_changed(struct bcm_op /* 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; @@ -562,6 +564,7 @@ static enum hrtimer_restart bcm_rx_timeo } /* 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;