diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-12-03 03:41:42 +0400 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2012-10-08 01:41:01 +0400 |
| commit | 642f7c50ec1863ca67367afbe0d95ab0646fa739 (patch) | |
| tree | bbb0242fa13d143abe62171317bb3acb1d53693a | |
| parent | 20b24cf258bdbf1d6f1fc634d24d13c26be14f6f (diff) | |
| download | linux-642f7c50ec1863ca67367afbe0d95ab0646fa739.tar.xz | |
tcp: drop SYN+FIN messages
commit fdf5af0daf8019cec2396cdef8fb042d80fe71fa upstream.
Denys Fedoryshchenko reported that SYN+FIN attacks were bringing his
linux machines to their limits.
Dont call conn_request() if the TCP flags includes SYN flag
Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | net/ipv4/tcp_input.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 4b148e5758c6..db755c416daf 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5634,6 +5634,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, goto discard; if (th->syn) { + if (th->fin) + goto discard; if (icsk->icsk_af_ops->conn_request(sk, skb) < 0) return 1; |