From: Vasiliy Kulikov Date: Sun, 20 Mar 2011 14:42:52 +0000 (+0100) Subject: netfilter: ipt_CLUSTERIP: fix buffer overflow X-Git-Tag: v2.6.39-rc5~40^2^2~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=961ed183a9fd080cf306c659b8736007e44065a5;p=platform%2Fupstream%2Fkernel-adaptation-pc.git netfilter: ipt_CLUSTERIP: fix buffer overflow '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 --- diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index 403ca57..d609ac3 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -664,8 +664,11 @@ 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);