This is a note to let you know that I've just added the patch titled

    tcp: detect SYN/data drop when F-RTO is disabled

to the 3.7-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tcp-detect-syn-data-drop-when-f-rto-is-disabled.patch
and it can be found in the queue-3.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From a8963d813f812a9c13baed12ec4c06a1c3443e7c Mon Sep 17 00:00:00 2001
From: Yuchung Cheng <[email protected]>
Date: Thu, 31 Jan 2013 11:16:46 -0800
Subject: tcp: detect SYN/data drop when F-RTO is disabled


From: Yuchung Cheng <[email protected]>

[ Upstream commit 66555e92fb7a619188c02cceae4bbc414f15f96d ]

On receiving the SYN-ACK, Fast Open checks icsk_retransmit for SYN
retransmission to detect SYN/data drops. But if F-RTO is disabled,
icsk_retransmit is reset at step D of tcp_fastretrans_alert() (
under tcp_ack()) before tcp_rcv_fastopen_synack(). The fix is to use
total_retrans instead which accounts for SYN retransmission regardless
the use of F-RTO.

Signed-off-by: Yuchung Cheng <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 net/ipv4/tcp_input.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5639,8 +5639,7 @@ static bool tcp_rcv_fastopen_synack(stru
         * the remote receives only the retransmitted (regular) SYNs: either
         * the original SYN-data or the corresponding SYN-ACK is lost.
         */
-       syn_drop = (cookie->len <= 0 && data &&
-                   inet_csk(sk)->icsk_retransmits);
+       syn_drop = (cookie->len <= 0 && data && tp->total_retrans);
 
        tcp_fastopen_cache_set(sk, mss, cookie, syn_drop);
 


Patches currently in stable-queue which might be from [email protected] are

queue-3.7/tcp-frto-should-not-set-snd_cwnd-to-0.patch
queue-3.7/tcp-fix-a-panic-on-up-machines-in-reqsk_fastopen_remove.patch
queue-3.7/tcp-detect-syn-data-drop-when-f-rto-is-disabled.patch
queue-3.7/tcp-fix-an-infinite-loop-in-tcp_slow_start.patch
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