netfilter: nft_osf: restrict it to ipv4

This expression only supports for ipv4, restrict it.

Fixes: b96af92d6eaf ("netfilter: nf_tables: implement Passive OS fingerprint module in nft_osf")
Acked-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c
index 18003433476cdaf37fe293bc265c67da3dbf6fd4..c02d5cb52143bcfa350388bd7325da7da9db57ba 100644 (file)
--- a/net/netfilter/nft_osf.c
+++ b/net/netfilter/nft_osf.c
@@ -28,6 +28,11 @@ static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs,
        struct nf_osf_data data;
        struct tcphdr _tcph;
 
+       if (nft_pf(pkt) != NFPROTO_IPV4) {
+               regs->verdict.code = NFT_BREAK;
+               return;
+       }
+
        if (pkt->tprot != IPPROTO_TCP) {
                regs->verdict.code = NFT_BREAK;
                return;
@@ -114,7 +119,6 @@ static int nft_osf_validate(const struct nft_ctx *ctx,
 
        switch (ctx->family) {
        case NFPROTO_IPV4:
-       case NFPROTO_IPV6:
        case NFPROTO_INET:
                hooks = (1 << NF_INET_LOCAL_IN) |
                        (1 << NF_INET_PRE_ROUTING) |