Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E56FAC433F5 for ; Mon, 13 Dec 2021 09:51:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234376AbhLMJvK (ORCPT ); Mon, 13 Dec 2021 04:51:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236167AbhLMJqG (ORCPT ); Mon, 13 Dec 2021 04:46:06 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B54B8C034020; Mon, 13 Dec 2021 01:41:19 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 80C04B80E1D; Mon, 13 Dec 2021 09:41:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B20F3C00446; Mon, 13 Dec 2021 09:41:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1639388477; bh=s8nLoGznIFyd8c0YEG546o/L3Eon+bmNWSRQt8mlErs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y0PczTIPBhtSVmaev85OOWKVLe9Ndwv8nL2/SyjzbwouHtEUM2BtSVzKav4PkJbvs KjKaHYiBKfLw0haBUk0YQjgfE3XUy29dUV9PT/yjTaD8DmpYJrUW0EH1P8rWeRQxbH Es5VvwQCxfhjwZWTJb7drQHVXfaMxQ6UTATGT/Q8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vincent Mailhol , Marc Kleine-Budde Subject: [PATCH 4.19 30/74] can: pch_can: pch_can_rx_normal: fix use after free Date: Mon, 13 Dec 2021 10:30:01 +0100 Message-Id: <20211213092931.817161270@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211213092930.763200615@linuxfoundation.org> References: <20211213092930.763200615@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: Vincent Mailhol commit 94cddf1e9227a171b27292509d59691819c458db upstream. After calling netif_receive_skb(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is dereferenced just after the call netif_receive_skb(skb). Reordering the lines solves the issue. Fixes: b21d18b51b31 ("can: Topcliff: Add PCH_CAN driver.") Link: https://lore.kernel.org/all/20211123111654.621610-1-mailhol.vincent@wanadoo.fr Cc: stable@vger.kernel.org Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/pch_can.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/can/pch_can.c +++ b/drivers/net/can/pch_can.c @@ -703,11 +703,11 @@ static int pch_can_rx_normal(struct net_ cf->data[i + 1] = data_reg >> 8; } - netif_receive_skb(skb); rcv_pkts++; stats->rx_packets++; quota--; stats->rx_bytes += cf->can_dlc; + netif_receive_skb(skb); pch_fifo_thresh(priv, obj_num); obj_num++;