[ 23/73] netfilter: ctnetlink: dont permit ct creation with random tuple

[Greg Kroah-Hartman]

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

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

From: Florian Westphal <fw@xxxxxxxxx>

commit 442fad9423b78319e0019a7f5047eddf3317afbc upstream.

Userspace can cause kernel panic by not specifying orig/reply
tuple: kernel will create a tuple with random stack values.

Problem is that tuple.dst.dir will be random, too, which
causes nf_ct_tuplehash_to_ctrack() to return garbage.

Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/netfilter/nf_conntrack_netlink.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1705,6 +1705,9 @@ ctnetlink_new_conntrack(struct sock *ctn
 		if (nlh->nlmsg_flags & NLM_F_CREATE) {
 			enum ip_conntrack_events events;
 
+			if (!cda[CTA_TUPLE_ORIG] || !cda[CTA_TUPLE_REPLY])
+				return -EINVAL;
+
 			ct = ctnetlink_create_conntrack(net, zone, cda, &otuple,
 							&rtuple, u3);
 			if (IS_ERR(ct))


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