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 EE6FAC433EF for ; Mon, 13 Dec 2021 09:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238263AbhLMJ76 (ORCPT ); Mon, 13 Dec 2021 04:59:58 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:44872 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238947AbhLMJzD (ORCPT ); Mon, 13 Dec 2021 04:55:03 -0500 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 sin.source.kernel.org (Postfix) with ESMTPS id 2B44ACE0B59; Mon, 13 Dec 2021 09:55:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7488C34601; Mon, 13 Dec 2021 09:54:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1639389298; bh=vLfbsrfu1YDuBJg1GcCh3k5NDnw1r47h40rMvlXP/LQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W/9TIugeZYmBhUEUyuh+ViYdppgH941wka5OaDbPRnSQRA9aFG7aWAqaQ5rtBFu8U kxoxKkWcwMNlME0AJySSr7I3GtfKE0WsjuPvJrExgmbXLwNJsD1O/aeDdB9kdN3aeO crQOVSXIYQZSN0GzjW/4aXxEt016kqURpi+H5fF4= 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 5.15 024/171] can: pch_can: pch_can_rx_normal: fix use after free Date: Mon, 13 Dec 2021 10:28:59 +0100 Message-Id: <20211213092945.882966631@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211213092945.091487407@linuxfoundation.org> References: <20211213092945.091487407@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 @@ -692,11 +692,11 @@ 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->len; + netif_receive_skb(skb); pch_fifo_thresh(priv, obj_num); obj_num++;