From: Pablo Neira Ayuso pablo@netfilter.org
commit 962e5a40358787105f126ab1dc01604da3d169e9 upstream.
Break rule evaluation on malformed TCP options.
Fixes: 99d1712bc41c ("netfilter: exthdr: tcp option set support") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nft_exthdr.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -236,7 +236,7 @@ static void nft_exthdr_tcp_set_eval(cons
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(cons 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(cons
return; } + return; +err: + regs->verdict.code = NFT_BREAK; }
static void nft_exthdr_sctp_eval(const struct nft_expr *expr,