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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 AEF11C43331 for ; Mon, 11 Nov 2019 18:36:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81CC6214E0 for ; Mon, 11 Nov 2019 18:36:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573497392; bh=27fDGEpqKQPn9KccCyYX91hENaUtYZICVPP1diLkpYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZcC+x91Wn8D6cSkcEN2wHiOblMZ4n+8UXGldwVuxnIN6GYw16D7EFHj+YYRTjCoLt vBK8lO0DTWYHhgdBnc5Xp4889rVUBlNNiVx+bp27ZJP0eGspy9P+4Fp/MUhTL/1Mat ZTssLjkIuB0P5R51xPXTwpO7cPaOwsxg4xRhce9I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728731AbfKKSgb (ORCPT ); Mon, 11 Nov 2019 13:36:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:54724 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728072AbfKKSg1 (ORCPT ); Mon, 11 Nov 2019 13:36:27 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EFD8521655; Mon, 11 Nov 2019 18:36:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573497386; bh=27fDGEpqKQPn9KccCyYX91hENaUtYZICVPP1diLkpYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZZxd0A7hWD10Fch3dGtQrByZW2D7nbHxjYrFktY8pziDKbAl4pTfzqoxWqOR/GXpg KFHAeGiiMZ1NbiuzhmcA8cyzKghH5lpS2CP0DViw7tkfBa9G1e/AYZJCQb++bu8Xgj yOEY38QIxl2JXvO8qwy8/BKvD812+la+y3oRaeXQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephane Grosjean , Marc Kleine-Budde Subject: [PATCH 4.14 035/105] can: peak_usb: fix a potential out-of-sync while decoding packets Date: Mon, 11 Nov 2019 19:28:05 +0100 Message-Id: <20191111181439.071913273@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191111181421.390326245@linuxfoundation.org> References: <20191111181421.390326245@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephane Grosjean commit de280f403f2996679e2607384980703710576fed upstream. When decoding a buffer received from PCAN-USB, the first timestamp read in a packet is a 16-bit coded time base, and the next ones are an 8-bit offset to this base, regardless of the type of packet read. This patch corrects a potential loss of synchronization by using a timestamp index read from the buffer, rather than an index of received data packets, to determine on the sizeof the timestamp to be read from the packet being decoded. Signed-off-by: Stephane Grosjean Fixes: 46be265d3388 ("can: usb: PEAK-System Technik PCAN-USB specific part") Cc: linux-stable Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/usb/peak_usb/pcan_usb.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- a/drivers/net/can/usb/peak_usb/pcan_usb.c +++ b/drivers/net/can/usb/peak_usb/pcan_usb.c @@ -108,7 +108,7 @@ struct pcan_usb_msg_context { u8 *end; u8 rec_cnt; u8 rec_idx; - u8 rec_data_idx; + u8 rec_ts_idx; struct net_device *netdev; struct pcan_usb *pdev; }; @@ -552,10 +552,15 @@ static int pcan_usb_decode_status(struct mc->ptr += PCAN_USB_CMD_ARGS; if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) { - int err = pcan_usb_decode_ts(mc, !mc->rec_idx); + int err = pcan_usb_decode_ts(mc, !mc->rec_ts_idx); if (err) return err; + + /* Next packet in the buffer will have a timestamp on a single + * byte + */ + mc->rec_ts_idx++; } switch (f) { @@ -638,10 +643,13 @@ static int pcan_usb_decode_data(struct p cf->can_dlc = get_can_dlc(rec_len); - /* first data packet timestamp is a word */ - if (pcan_usb_decode_ts(mc, !mc->rec_data_idx)) + /* Only first packet timestamp is a word */ + if (pcan_usb_decode_ts(mc, !mc->rec_ts_idx)) goto decode_failed; + /* Next packet in the buffer will have a timestamp on a single byte */ + mc->rec_ts_idx++; + /* read data */ memset(cf->data, 0x0, sizeof(cf->data)); if (status_len & PCAN_USB_STATUSLEN_RTR) { @@ -695,7 +703,6 @@ static int pcan_usb_decode_msg(struct pe /* handle normal can frames here */ } else { err = pcan_usb_decode_data(&mc, sl); - mc.rec_data_idx++; } }