[PATCH 3.16.y-ckt 052/126] netfilter: ipset: small potential read beyond the end of buffer

[Luis Henriques]

3.16.7-ckt5 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter at oracle.com>

commit 2196937e12b1b4ba139806d132647e1651d655df upstream.

We could be reading 8 bytes into a 4 byte buffer here.  It seems
harmless but adding a check is the right thing to do and it silences a
static checker warning.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Acked-by: Jozsef Kadlecsik <kadlec at blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/netfilter/ipset/ip_set_core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 6582dce828b5..6850c3c4d6d3 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1838,6 +1838,12 @@ ip_set_sockfn_get(struct sock *sk, int optval, void __user *user, int *len)
 	if (*op < IP_SET_OP_VERSION) {
 		/* Check the version at the beginning of operations */
 		struct ip_set_req_version *req_version = data;
+
+		if (*len < sizeof(struct ip_set_req_version)) {
+			ret = -EINVAL;
+			goto done;
+		}
+
 		if (req_version->version != IPSET_PROTOCOL) {
 			ret = -EPROTO;
 			goto done;
-- 
2.1.4