From 10670abe111568c7f662981df79ebe4de23ce658 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 30 Nov 2021 11:34:04 +0100 Subject: [PATCH] netfilter: nft_exthdr: break evaluation if setting TCP option fails [ Upstream commit 962e5a40358787105f126ab1dc01604da3d169e9 ] Break rule evaluation on malformed TCP options. Fixes: 99d1712bc41c ("netfilter: exthdr: tcp option set support") Signed-off-by: Pablo Neira Ayuso Stable-dep-of: 28427f368f0e ("netfilter: nft_exthdr: Fix non-linear header modification") Signed-off-by: Sasha Levin --- net/netfilter/nft_exthdr.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index 73f82483f242..10a510fef75c 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -236,7 +236,7 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr, tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len); if (!tcph) - return; + goto err; opt = (u8 *)tcph; for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) { @@ -251,16 +251,16 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr, continue; if (i + optl > tcphdr_len || priv->len + priv->offset > optl) - return; + goto err; if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + i + priv->len)) - return; + goto err; tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len); if (!tcph) - return; + goto err; offset = i + priv->offset; @@ -303,6 +303,9 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr, return; } + return; +err: + regs->verdict.code = NFT_BREAK; } static void nft_exthdr_sctp_eval(const struct nft_expr *expr,