connector: use nlmsg_len() to check message length

The current code tests the length of the whole netlink message to be
at least as long to fit a cn_msg. This is wrong as nlmsg_len includes
the length of the netlink message header. Use nlmsg_len() instead to
fix this "off-by-NLMSG_HDRLEN" size check.

Cc: stable@vger.kernel.org  # v2.6.14+
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mathias Krause 2013-09-30 22:03:07 +02:00 committed by David S. Miller
parent e727ca82e0
commit 162b2bedc0
1 changed files with 4 additions and 3 deletions

View File

@ -157,17 +157,18 @@ static int cn_call_callback(struct sk_buff *skb)
static void cn_rx_skb(struct sk_buff *__skb)
{
struct nlmsghdr *nlh;
int err;
struct sk_buff *skb;
int len, err;
skb = skb_get(__skb);
if (skb->len >= NLMSG_HDRLEN) {
nlh = nlmsg_hdr(skb);
len = nlmsg_len(nlh);
if (nlh->nlmsg_len < sizeof(struct cn_msg) ||
if (len < (int)sizeof(struct cn_msg) ||
skb->len < nlh->nlmsg_len ||
nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
len > CONNECTOR_MAX_MSG_SIZE) {
kfree_skb(skb);
return;
}