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=-13.1 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,URIBL_BLOCKED,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 7977EC433E8 for ; Tue, 14 Jul 2020 14:39:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C9FC2256D for ; Tue, 14 Jul 2020 14:39:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594737590; bh=qCrRnVRA5KhdFuJB9e1HF7uBLgDqdl/68XqOah8yMvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nWarpYfeGFFggjItOfSjhO1NnprNvMSpo/YiBuIg1w4T6fuSjv56CFpD7fMUi9dfs dGuNcrI+ZWuXVyq7cOMSEcaa0tQQfdkbSdGU+MTHjAIzp9fn2Vb5s+qLzZcNh8yw8R Y7myOnb0ye7OfQCdyf2sa03bIFFvGXuT7ZOt/eLs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729139AbgGNOjt (ORCPT ); Tue, 14 Jul 2020 10:39:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:55260 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729124AbgGNOjs (ORCPT ); Tue, 14 Jul 2020 10:39:48 -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 CF6282256C; Tue, 14 Jul 2020 14:39:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594737587; bh=qCrRnVRA5KhdFuJB9e1HF7uBLgDqdl/68XqOah8yMvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nImYRFra2KUDxgxxdd8bgF3XmKo1tU6uCZJiwg80xgRJq3kM6JEvCq2T3mUzHNDFi zKC9d34uHCmsl3UynqAYPFVS/p9OHqjrTKmjjv5+v4yR4I9AE4tvj8Veu7uIFRkk6O fm4Q3HpDbmh2sgBdoHjAx+LxYqS9PC9OB/I0uoRU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xie He , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 08/13] drivers/net/wan/lapbether: Fixed the value of hard_header_len Date: Tue, 14 Jul 2020 10:39:32 -0400 Message-Id: <20200714143937.4035685-8-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200714143937.4035685-1-sashal@kernel.org> References: <20200714143937.4035685-1-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: Xie He [ Upstream commit 9dc829a135fb5927f1519de11286e2bbb79f5b66 ] When this driver transmits data, first this driver will remove a pseudo header of 1 byte, then the lapb module will prepend the LAPB header of 2 or 3 bytes, then this driver will prepend a length field of 2 bytes, then the underlying Ethernet device will prepend its own header. So, the header length required should be: -1 + 3 + 2 + "the header length needed by the underlying device". This patch fixes kernel panic when this driver is used with AF_PACKET SOCK_DGRAM sockets. Signed-off-by: Xie He Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/wan/lapbether.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c index 0e3f8ed84660e..ac34257e9f203 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -308,7 +308,6 @@ static void lapbeth_setup(struct net_device *dev) dev->netdev_ops = &lapbeth_netdev_ops; dev->needs_free_netdev = true; dev->type = ARPHRD_X25; - dev->hard_header_len = 3; dev->mtu = 1000; dev->addr_len = 0; } @@ -329,6 +328,14 @@ static int lapbeth_new_device(struct net_device *dev) if (!ndev) goto out; + /* When transmitting data: + * first this driver removes a pseudo header of 1 byte, + * then the lapb module prepends an LAPB header of at most 3 bytes, + * then this driver prepends a length field of 2 bytes, + * then the underlying Ethernet device prepends its own header. + */ + ndev->hard_header_len = -1 + 3 + 2 + dev->hard_header_len; + lapbeth = netdev_priv(ndev); lapbeth->axdev = ndev; -- 2.25.1