[TCP] FRTO: Plug potential LOST-bit leak

It might be possible that, in some extreme scenario that
I just cannot now construct in my mind, end_seq <=
frto_highmark check does not match causing the lost_out
and LOST bits become out-of-sync due to clearing and
recounting in the loop.

This may fix LOST-bit leak reported by Chazarain Guillaume
<guichaz@yahoo.fr>.

Signed-off-by: Ilpo Jrvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ilpo Jrvinen 2007-11-13 21:03:13 -08:00 committed by David S. Miller
parent 746aa32d28
commit 23aeeec365
1 changed files with 3 additions and 1 deletions

View File

@ -1704,6 +1704,8 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
tcp_for_write_queue(skb, sk) {
if (skb == tcp_send_head(sk))
break;
TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
/*
* Count the retransmission made on RTO correctly (only when
* waiting for the first ACK and did not get it)...
@ -1717,7 +1719,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
} else {
if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS)
tp->undo_marker = 0;
TCP_SKB_CB(skb)->sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
}
/* Don't lost mark skbs that were fwd transmitted after RTO */