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 B41E6C433DF for ; Mon, 24 Aug 2020 17:12:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 94C722074D for ; Mon, 24 Aug 2020 17:12:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598289121; bh=Y+dzBIhGF+kbEmw58dJ4IZaOWYovq8f4Yu+nhkSCnkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KM7ubBo7rJ/8DZ6EoDrSaUsotqi+LtejQgc09L94MetT7WgKHd5PsZJ/9HZi96iPZ iEwYDHKsm6mkjyRO5if/6+1iJY/RIXGvUdIdiDPkB4gY2KM3lkLdZBUoVJiFH4ifdZ nXnZX5UMEKHtkf8GsoAPg9emWFyM+gEcCwwXCY9s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728406AbgHXRLu (ORCPT ); Mon, 24 Aug 2020 13:11:50 -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: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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