[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 <posthuma@sangine.com>.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 2 deletions

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index 170d625fad67..0a72eab14620 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -812,8 +812,10 @@ void ip_conntrack_tcp_update(struct sk_buff *skb,
 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,
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 3b9ad7f6eb5d..153d6619993a 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -769,8 +769,10 @@ EXPORT_SYMBOL_GPL(nf_conntrack_tcp_update);
 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,