From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasiliy Kulikov Subject: [PATCH] ipv4: netfilter: ipt_CLUSTERIP: fix buffer overflow Date: Thu, 10 Mar 2011 21:12:19 +0300 Message-ID: <1299780740-32652-1-git-send-email-segoon@openwall.com> Cc: security@kernel.org, Patrick McHardy , "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org To: linux-kernel@vger.kernel.org Return-path: Sender: netfilter-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org buffer string is copied from userspace. It is not checked whether it is zero terminated. This may lead to overflow inside of simple_strtoul(). 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 --- Compile tested. net/ipv4/netfilter/ipt_CLUSTERIP.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index 403ca57..7aabf9a 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -666,6 +666,7 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input, if (copy_from_user(buffer, input, PROC_WRITELEN)) return -EFAULT; + buffer[sizeof(buffer)-1] = 0; if (*buffer == '+') { nodenum = simple_strtoul(buffer+1, NULL, 10); -- 1.7.0.4