From patchwork Tue Feb 12 09:22:38 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [1/1] netfilter: ctnetlink: don't permit ct creation with random tuple Date: Mon, 11 Feb 2013 23:22:38 -0000 From: Florian Westphal X-Patchwork-Id: 219751 Message-Id: <1360660958-29494-1-git-send-email-fw@strlen.de> To: netfilter-devel Cc: Florian Westphal 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))