Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754498AbcDRChX (ORCPT ); Sun, 17 Apr 2016 22:37:23 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36576 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932174AbcDRChS (ORCPT ); Sun, 17 Apr 2016 22:37:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Willem de Bruijn , "David S. Miller" Subject: [PATCH 4.4 044/137] ax25: add link layer header validation function Date: Mon, 18 Apr 2016 11:28:26 +0900 Message-Id: <20160418022510.147285865@linuxfoundation.org> X-Mailer: git-send-email 2.8.0 In-Reply-To: <20160418022507.236379264@linuxfoundation.org> References: <20160418022507.236379264@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1281 Lines: 49 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Willem de Bruijn [ Upstream commit ea47781c26510e5d97f80f9aceafe9065bd5e3aa ] As variable length protocol, AX25 fails link layer header validation tests based on a minimum length. header_ops.validate allows protocols to validate headers that are shorter than hard_header_len. Implement this callback for AX25. See also http://comments.gmane.org/gmane.linux.network/401064 Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ax25/ax25_ip.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/net/ax25/ax25_ip.c +++ b/net/ax25/ax25_ip.c @@ -228,8 +228,23 @@ netdev_tx_t ax25_ip_xmit(struct sk_buff } #endif +static bool ax25_validate_header(const char *header, unsigned int len) +{ + ax25_digi digi; + + if (!len) + return false; + + if (header[0]) + return true; + + return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL, + NULL); +} + const struct header_ops ax25_header_ops = { .create = ax25_hard_header, + .validate = ax25_validate_header, }; EXPORT_SYMBOL(ax25_header_ops);