[PATCH net 03/11] netfilter: nft_osf: restrict it to ipv4

Pablo Neira Ayuso
2026-04-16T13:15:06Z

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>
---
net/netfilter/nft_osf.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c
index 1c0b493ef0a9..bdc2f6c90e2f 100644
--- 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) |
--
2.47.3