From 23aeeec365dcf8bc87fae44c533e50d0bb4f23cc Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=E4rvinen?= Date: Tue, 13 Nov 2007 21:03:13 -0800 Subject: [PATCH] [TCP] FRTO: Plug potential LOST-bit leak MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 . Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index b59da5308ac0..12ae9a68cdaa 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -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 */ -- 2.20.1