Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 11/23] tcp: drop SYN+FIN messages | Date | Tue, 17 Jul 2012 17:12:04 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <eric.dumazet@gmail.com>
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>
--- net/ipv4/tcp_input.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5761,6 +5761,8 @@ int tcp_rcv_state_process(struct sock *s goto discard; if (th->syn) { + if (th->fin) + goto discard; if (icsk->icsk_af_ops->conn_request(sk, skb) < 0) return 1;
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