3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yuchung Cheng <ycheng@xxxxxxxxxx> [ Upstream commit 031afe4990a7c9dbff41a3a742c44d3e740ea0a1 ] On receiving an ACK that covers the loss probe sequence, TLP immediately sets the congestion state to Open, even though some packets are not recovered and retransmisssion are on the way. The later ACks may trigger a WARN_ON check in step D of tcp_fastretrans_alert(), e.g., https://bugzilla.redhat.com/show_bug.cgi?id=989251 The fix is to follow the similar procedure in recovery by calling tcp_try_keep_open(). The sender switches to Open state if no packets are retransmissted. Otherwise it goes to Disorder and let subsequent ACKs move the state to Recovery or Open. Reported-By: Michael Sterrett <michael@xxxxxxxxxxxxx> Tested-By: Dormando <dormando@xxxxxxxxx> Signed-off-by: Yuchung Cheng <ycheng@xxxxxxxxxx> Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3284,7 +3284,7 @@ static void tcp_process_tlp_ack(struct s tcp_init_cwnd_reduction(sk, true); tcp_set_ca_state(sk, TCP_CA_CWR); tcp_end_cwnd_reduction(sk); - tcp_set_ca_state(sk, TCP_CA_Open); + tcp_try_keep_open(sk); NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSSPROBERECOVERY); } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html