From: Pablo Neira Ayuso pablo@netfilter.org
stable inclusion from linux-4.19.198 commit 3225cd78880a15928f8930e3de698a6edca63f42
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[ 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 pablo@netfilter.org Reported-by: kernel test robot lkp@intel.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- 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) {