summary refs log tree commit diff
path: root/net/ipv4/tcp_input.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 036f85738141..1db663983587 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5964,7 +5964,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 
 	req = tp->fastopen_rsk;
 	if (req != NULL) {
-		BUG_ON(sk->sk_state != TCP_SYN_RECV &&
+		WARN_ON_ONCE(sk->sk_state != TCP_SYN_RECV &&
 		    sk->sk_state != TCP_FIN_WAIT1);
 
 		if (tcp_check_req(sk, skb, req, NULL, true) == NULL)
@@ -6053,7 +6053,15 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 			 * ACK we have received, this would have acknowledged
 			 * our SYNACK so stop the SYNACK timer.
 			 */
-			if (acceptable && req != NULL) {
+			if (req != NULL) {
+				/* Return RST if ack_seq is invalid.
+				 * Note that RFC793 only says to generate a
+				 * DUPACK for it but for TCP Fast Open it seems
+				 * better to treat this case like TCP_SYN_RECV
+				 * above.
+				 */
+				if (!acceptable)
+					return 1;
 				/* We no longer need the request sock. */
 				reqsk_fastopen_remove(sk, req, false);
 				tcp_rearm_rto(sk);