From: Florian Westphal Date: Mon, 11 Feb 2013 23:22:38 +0000 (+0000) Subject: netfilter: ctnetlink: don't permit ct creation with random tuple X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=442fad9423b78319e0019a7f5047eddf3317afbc;p=linux-beck.git netfilter: ctnetlink: don't permit ct creation with random tuple 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 Signed-off-by: Pablo Neira Ayuso --- diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 627b0e50b238..a081915e0531 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1705,6 +1705,9 @@ 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))