netfilter: nft_socket: make cgroup match work in input too

cgroupv2 helper function ignores the already-looked up sk
and uses skb->sk instead.

Just pass sk from the calling function instead; this will
make cgroup matching work for udp and tcp in input even when
edemux did not set skb->sk already.

Fixes: e0bb96db ("netfilter: nft_socket: add support for cgroupsv2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Topi Miettinen <toiwoton@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_socket.c

@@ -37,12 +37,11 @@ static void nft_socket_wildcard(const struct nft_pktinfo *pkt,
 
 #ifdef CONFIG_SOCK_CGROUP_DATA
 static noinline bool
-nft_sock_get_eval_cgroupv2(u32 *dest, const struct nft_pktinfo *pkt, u32 level)
+nft_sock_get_eval_cgroupv2(u32 *dest, struct sock *sk, const struct nft_pktinfo *pkt, u32 level)
 {
-	struct sock *sk = skb_to_full_sk(pkt->skb);
 	struct cgroup *cgrp;
 
-	if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk)))
+	if (!sk_fullsock(sk))
 		return false;
 
 	cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
@@ -109,7 +108,7 @@ static void nft_socket_eval(const struct nft_expr *expr,
 		break;
 #ifdef CONFIG_SOCK_CGROUP_DATA
 	case NFT_SOCKET_CGROUPV2:
-		if (!nft_sock_get_eval_cgroupv2(dest, pkt, priv->level)) {
+		if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) {
 			regs->verdict.code = NFT_BREAK;
 			return;
 		}