nft_socket lacks .validate hooks to restrict its use to the prerouting
and input chains.
Adding such restriction now may break existing setups, also, if skb
has a socket attached to it, nft_socket will work fine.
Therefore, check if the incoming interface is available and NFT_BREAK
in case neither skb->sk nor input device are set.
Reported-by: Topi Miettinen <toiwoton@xxxxxxxxx>
Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
net/netfilter/nft_socket.c | 41 +++++++++++++++++++++++++-------------
1 file changed, 27 insertions(+), 14 deletions(-)
diff --git a/net/netfilter/nft_socket.c b/net/netfilter/nft_socket.c
index 6d9e8e0a3a7d..cbd1e4523ace 100644
--- a/net/netfilter/nft_socket.c
+++ b/net/netfilter/nft_socket.c
@@ -54,6 +54,32 @@ nft_sock_get_eval_cgroupv2(u32 *dest, struct sock *sk, const struct nft_pktinfo
}
#endif
+static struct sock *nft_socket_do_lookup(const struct nft_pktinfo *pkt)
+{
+ const struct net_device *indev = nft_in(pkt);
+ const struct sk_buff *skb = pkt->skb;
+ struct sock *sk = NULL;
+
+ if (!indev)
+ return NULL;
+
+ switch(nft_pf(pkt)) {
+ case NFPROTO_IPV4:
+ sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev);
+ break;
+#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
+ case NFPROTO_IPV6:
+ sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev);
+ break;
+#endif
+ default:
+ WARN_ON_ONCE(1);
+ break;
+ }
+
+ return sk;
+}
+
static void nft_socket_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
@@ -67,20 +93,7 @@ static void nft_socket_eval(const struct nft_expr *expr,
sk = NULL;
if (!sk)
- switch(nft_pf(pkt)) {
- case NFPROTO_IPV4:
- sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt));
- break;
-#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
- case NFPROTO_IPV6:
- sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt));
- break;
-#endif
- default:
- WARN_ON_ONCE(1);
- regs->verdict.code = NFT_BREAK;
- return;
- }
+ sk = nft_socket_do_lookup(pkt);
if (!sk) {
regs->verdict.code = NFT_BREAK;
--
2.35.1
