Commit ac74dea8 authored Feb 14, 2019 by Devi Sandeep Endluri V V Committed by Gerrit - the friendly Code Review server Apr 13, 2020

tcp: Reset tcp connections in SYN-SENT state



Userspace sends tcp connection (sock) destroy on network permission
change. Kernel though doesn't send reset for the connections in
SYN-SENT state and these connections continue to remain. Even as
per RFC 793, there is no hard rule to not send RST on ABORT in
this state. Modify tcp_abort and tcp_disconnect behavior to send
RST for connections in syn-sent state to avoid lingering
connections on network switch.

CRs-Fixed: 2396964
Change-Id: If931fb979e519c474697d82d8c9dbaf0edb626e3
Signed-off-by: Devi Sandeep Endluri V V <dendluri@codeaurora.org>

parent 2b71825e

net/ipv4/tcp.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -2510,7 +2510,7 @@ static inline bool tcp_need_reset(int state)
		{
		return (1 << state) &
		(TCPF_ESTABLISHED \| TCPF_CLOSE_WAIT \| TCPF_FIN_WAIT1 \|
		TCPF_FIN_WAIT2 \| TCPF_SYN_RECV);
		TCPF_FIN_WAIT2 \| TCPF_SYN_RECV \| TCPF_SYN_SENT);
		}

		static void tcp_rtx_queue_purge(struct sock *sk)
		@@ -2572,8 +2572,7 @@ int tcp_disconnect(struct sock *sk, int flags)
		*/
		tcp_send_active_reset(sk, gfp_any());
		sk->sk_err = ECONNRESET;
		} else if (old_state == TCP_SYN_SENT)
		sk->sk_err = ECONNRESET;
		}

		tcp_clear_xmit_timers(sk);
		__skb_queue_purge(&sk->sk_receive_queue);