From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: [PATCH 1/1] netfilter: ctnetlink: don't permit ct creation with random tuple Date: Tue, 12 Feb 2013 10:22:38 +0100 Message-ID: <1360660958-29494-1-git-send-email-fw@strlen.de> Cc: Florian Westphal To: netfilter-devel Return-path: Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:38728 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932740Ab3BLJUq (ORCPT ); Tue, 12 Feb 2013 04:20:46 -0500 Sender: netfilter-devel-owner@vger.kernel.org List-ID: 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 --- 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