From: Stephen Moorby Subject: [PATCH 1/1] net/x25: fix address parsing bug in x25_parse_address_block. Date: Wed, 19 Jun 2013 12:13:28 +0100 Message-ID: <51C19258.9070504@keyparts.co.uk> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: andrew.hendry@gmail.com, davem@davemloft.net, sasha.levin@oracle.com, akpm@linux-foundation.org, paulmck@linux.vnet.ibm.com, jiri@resnulli.us, linux-x25@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org From 01ba835311f6d2e2bbffc74703d704dc07803b53 Mon Sep 17 00:00:00 2001 From: Stephen Moorby Date: Wed, 19 Jun 2013 11:48:53 +0100 Subject: [PATCH 1/1] net/x25: fix address parsing bug in x25_parse_address_block. This problem was discovered when a linux box was incorrectly rejecting calls from some X.25 equipment. The problem was diagnosed to an incorrect address length calculation in 'x25_parse_address_block', the calculation did not account for the address digits being BCD encoded. The correct calculation is already performed on line 155. Patched on linux-next 18-Jun-2013 Tested on 2.6.32-45-generic Signed-off-by: Stephen Moorby --- net/x25/af_x25.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 1d964e2..eb6c1f9 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -98,7 +98,8 @@ int x25_parse_address_block(struct sk_buff *skb, } len = *skb->data; - needed = 1 + (len >> 4) + (len & 0x0f); + /* need 1 for address length + bytes for BCD encoding of 2 addresses */ + needed = 1 + (((len >> 4) + (len & 0x0f) + 1) >> 1); if (!pskb_may_pull(skb, needed)) { /* packet is too short to hold the addresses it claims -- 1.8.1.2