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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 65CBAC433E4 for ; Mon, 24 Aug 2020 17:12:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BC8A2063A for ; Mon, 24 Aug 2020 17:12:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598289136; bh=Y+dzBIhGF+kbEmw58dJ4IZaOWYovq8f4Yu+nhkSCnkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=io2aULTnMDOx57wz7nWqeErfCQ2zS7TG4HOCnJAkavyjzoBgXvlAjhwSFYdGgyHnb OgXVlQZ+AJdpNwZezjYFgHx3qcckDVo/gXY6zL8PAwIpjDobV3XzmJ84n5JYbowR+B /b3JGcH72hRqqU5xB50Uki0E6NPwFbBXb7SZ6V3w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728249AbgHXRLq (ORCPT ); Mon, 24 Aug 2020 13:11:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:40360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728392AbgHXQhy (ORCPT ); Mon, 24 Aug 2020 12:37:54 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 735F022D70; Mon, 24 Aug 2020 16:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598287030; bh=Y+dzBIhGF+kbEmw58dJ4IZaOWYovq8f4Yu+nhkSCnkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ov6q7qK3VBYSw1I08FHAy5RhExDJDcFUz0SVjqJdKN46zKfS0bDZ3pr9iGXX2x/Uz szUYn1aNRK1iVzS4WTsk97pIzopuNOqpUHMOR5Pdh2MjhailubQE+bwyop4CqqoApR 4S/JTsPkA9dH719zfKcFcBYrsvopDntHVuNtYL1s= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oleksij Rempel , Marc Kleine-Budde , Sasha Levin , linux-can@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.7 26/54] can: j1939: transport: j1939_xtp_rx_dat_one(): compare own packets to detect corruptions Date: Mon, 24 Aug 2020 12:36:05 -0400 Message-Id: <20200824163634.606093-26-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200824163634.606093-1-sashal@kernel.org> References: <20200824163634.606093-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-can-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org From: Oleksij Rempel [ Upstream commit e052d0540298bfe0f6cbbecdc7e2ea9b859575b2 ] Since the stack relays on receiving own packets, it was overwriting own transmit buffer from received packets. At least theoretically, the received echo buffer can be corrupt or changed and the session partner can request to resend previous data. In this case we will re-send bad data. With this patch we will stop to overwrite own TX buffer and use it for sanity checking. Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/r/20200807105200.26441-6-o.rempel@pengutronix.de Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- net/can/j1939/transport.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index 9f99af5b0b11e..3e9c377b0dcce 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -1769,7 +1769,20 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session, } tpdat = se_skb->data; - memcpy(&tpdat[offset], &dat[1], nbytes); + if (!session->transmission) { + memcpy(&tpdat[offset], &dat[1], nbytes); + } else { + int err; + + err = memcmp(&tpdat[offset], &dat[1], nbytes); + if (err) + netdev_err_once(priv->ndev, + "%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n", + __func__, session, + nbytes, &dat[1], + nbytes, &tpdat[offset]); + } + if (packet == session->pkt.rx) session->pkt.rx++; -- 2.25.1