From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758364Ab2CMATl (ORCPT ); Mon, 12 Mar 2012 20:19:41 -0400 Received: from mail.windriver.com ([147.11.1.11]:46884 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932308Ab2CMASW (ORCPT ); Mon, 12 Mar 2012 20:18:22 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Vasiliy Kulikov , Patrick McHardy , Paul Gortmaker Subject: [34-longterm 040/196] netfilter: ipt_CLUSTERIP: fix buffer overflow Date: Mon, 12 Mar 2012 20:12:48 -0400 Message-Id: <1331597724-31358-41-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.3 In-Reply-To: <1331597724-31358-1-git-send-email-paul.gortmaker@windriver.com> References: <1331597724-31358-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vasiliy Kulikov ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. ------------------- commit 961ed183a9fd080cf306c659b8736007e44065a5 upstream. 'buffer' string is copied from userspace. It is not checked whether it is zero terminated. This may lead to overflow inside of simple_strtoul(). Changli Gao suggested to copy not more than user supplied 'size' bytes. It was introduced before the git epoch. Files "ipt_CLUSTERIP/*" are root writable only by default, however, on some setups permissions might be relaxed to e.g. network admin user. Signed-off-by: Vasiliy Kulikov Acked-by: Changli Gao Signed-off-by: Patrick McHardy Signed-off-by: Paul Gortmaker --- net/ipv4/netfilter/ipt_CLUSTERIP.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index ab82840..e8bd977 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -663,8 +663,11 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input, char buffer[PROC_WRITELEN+1]; unsigned long nodenum; - if (copy_from_user(buffer, input, PROC_WRITELEN)) + if (size > PROC_WRITELEN) + return -EIO; + if (copy_from_user(buffer, input, size)) return -EFAULT; + buffer[size] = 0; if (*buffer == '+') { nodenum = simple_strtoul(buffer+1, NULL, 10); -- 1.7.9.3