From fb9c9649a1d0a65a8f94f784aa18252a0dd584c1 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sat, 29 Oct 2016 03:01:50 +0200 Subject: [PATCH] netfilter: connmark: ignore skbs with magic untracked conntrack objects The (percpu) untracked conntrack entries can end up with nonzero connmarks. The 'untracked' conntrack objects are merely a way to distinguish INVALID (i.e. protocol connection tracker says payload doesn't meet some requirements or packet was never seen by the connection tracking code) from packets that are intentionally not tracked (some icmpv6 types such as neigh solicitation, or by using 'iptables -j CT --notrack' option). Untracked conntrack objects are implementation detail, we might as well use invalid magic address instead to tell INVALID and UNTRACKED apart. Check skb->nfct for untracked dummy and behave as if skb->nfct is NULL. Reported-by: XU Tianwen Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_connmark.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c index 69f78e96fdb4..b83e158e116a 100644 --- a/net/netfilter/xt_connmark.c +++ b/net/netfilter/xt_connmark.c @@ -44,7 +44,7 @@ connmark_tg(struct sk_buff *skb, const struct xt_action_param *par) u_int32_t newmark; ct = nf_ct_get(skb, &ctinfo); - if (ct == NULL) + if (ct == NULL || nf_ct_is_untracked(ct)) return XT_CONTINUE; switch (info->mode) { @@ -97,7 +97,7 @@ connmark_mt(const struct sk_buff *skb, struct xt_action_param *par) const struct nf_conn *ct; ct = nf_ct_get(skb, &ctinfo); - if (ct == NULL) + if (ct == NULL || nf_ct_is_untracked(ct)) return false; return ((ct->mark & info->mask) == info->mark) ^ info->invert;