From 3225cd78880a15928f8930e3de698a6edca63f42 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 10 Jun 2021 20:20:31 +0200 Subject: [PATCH] netfilter: nft_osf: check for TCP packet before further processing [ Upstream commit 8f518d43f89ae00b9cf5460e10b91694944ca1a8 ] The osf expression only supports for TCP packets, add a upfront sanity check to skip packet parsing if this is not a TCP packet. Fixes: b96af92d6eaf ("netfilter: nf_tables: implement Passive OS fingerprint module in nft_osf") Signed-off-by: Pablo Neira Ayuso Reported-by: kernel test robot Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nft_osf.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c index a003533ff4d93..e259454b6a643 100644 --- a/net/netfilter/nft_osf.c +++ b/net/netfilter/nft_osf.c @@ -22,6 +22,11 @@ static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs, struct tcphdr _tcph; const char *os_name; + if (pkt->tprot != IPPROTO_TCP) { + regs->verdict.code = NFT_BREAK; + return; + } + tcp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(struct tcphdr), &_tcph); if (!tcp) { -- 2.47.2