-stable review patch. If anyone has any objections, please let us know. ------------------ From: Patrick McHardy [NETFILTER]: tcp conntrack: accept SYN|URG as valid Some stacks apparently send packets with SYN|URG set. Linux accepts these packets, so TCP conntrack should to. Pointed out by Martijn Posthuma . Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/ip_conntrack_proto_tcp.c | 4 +++- net/netfilter/nf_conntrack_proto_tcp.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) --- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c +++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c @@ -821,8 +821,10 @@ void ip_conntrack_tcp_update(struct sk_b static const u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG) + 1] = { [TH_SYN] = 1, - [TH_SYN|TH_ACK] = 1, [TH_SYN|TH_PUSH] = 1, + [TH_SYN|TH_URG] = 1, + [TH_SYN|TH_PUSH|TH_URG] = 1, + [TH_SYN|TH_ACK] = 1, [TH_SYN|TH_ACK|TH_PUSH] = 1, [TH_RST] = 1, [TH_RST|TH_ACK] = 1, --- a/net/netfilter/nf_conntrack_proto_tcp.c +++ b/net/netfilter/nf_conntrack_proto_tcp.c @@ -778,8 +778,10 @@ EXPORT_SYMBOL_GPL(nf_conntrack_tcp_updat static u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG) + 1] = { [TH_SYN] = 1, - [TH_SYN|TH_ACK] = 1, [TH_SYN|TH_PUSH] = 1, + [TH_SYN|TH_URG] = 1, + [TH_SYN|TH_PUSH|TH_URG] = 1, + [TH_SYN|TH_ACK] = 1, [TH_SYN|TH_ACK|TH_PUSH] = 1, [TH_RST] = 1, [TH_RST|TH_ACK] = 1, --