[PATCH 6.1 582/609] netfilter: bridge: release template ct on non-IP path

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zhiling Zou <[email protected]>

commit d45cc8020d7c0a9f01dee42ff5c40bc14c9af72f upstream.

A bridge nftables ct zone set rule can attach a conntrack template to
an skb before nf_ct_bridge_pre() sees it. For non-IPv4 and non-IPv6
EtherTypes, nf_ct_bridge_pre() currently overwrites skb->_nfct with
IP_CT_UNTRACKED without releasing the existing template reference.

That makes the per-cpu template, and any temporary templates allocated
for concurrent use, unreachable and leaks memory until the host runs out
of slab.

Reset the skb conntrack state before marking the frame untracked so the
existing template reference is dropped on the non-IP path.

Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system")
Cc: [email protected]
Reported-by: Vega <[email protected]>
Signed-off-by: Zhiling Zou <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 net/bridge/netfilter/nf_conntrack_bridge.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/bridge/netfilter/nf_conntrack_bridge.c
+++ b/net/bridge/netfilter/nf_conntrack_bridge.c
@@ -281,6 +281,7 @@ static unsigned int nf_ct_bridge_pre(voi
 		ret = nf_ct_br_defrag6(skb, &bridge_state);
 		break;
 	default:
+		nf_reset_ct(skb);
 		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
 		return NF_ACCEPT;
 	}