From: Florian Westphal <fw@strlen.de>
To: netfilter-devel <netfilter-devel@vger.kernel.org>
Cc: Florian Westphal <fw@strlen.de>
Subject: [PATCH 1/1] netfilter: ctnetlink: don't permit ct creation with random tuple
Date: Tue, 12 Feb 2013 10:22:38 +0100 [thread overview]
Message-ID: <1360660958-29494-1-git-send-email-fw@strlen.de> (raw)
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>
---
net/netfilter/nf_conntrack_netlink.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 7bbfb3d..e592281 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1596,6 +1596,9 @@ 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))
--
1.7.8.6
next reply other threads:[~2013-02-12 9:20 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-12 9:22 Florian Westphal [this message]
2013-02-12 12:24 ` [PATCH 1/1] netfilter: ctnetlink: don't permit ct creation with random tuple Pablo Neira Ayuso
2013-02-12 12:43 ` Florian Westphal
2013-02-12 13:10 ` Pablo Neira Ayuso
2013-02-12 22:35 ` Pablo Neira Ayuso
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