[ 101/136 ] netfilter: ctnetlink: dont permit ct creation with random tuple

Steven Rostedt
2013-05-18T03:11:37Z

[-- Attachment #1: 0101-netfilter-ctnetlink-don-t-permit-ct-creation-with-ra.patch --]
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3.6.11.4 stable review patch.
If anyone has any objections, please let me know.

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

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 442fad9423b78319e0019a7f5047eddf3317afbc ]

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@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
net/netfilter/nf_conntrack_netlink.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 9807f32..0f15779 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1579,6 +1579,9 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
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))
--
1.7.10.4