From: Ilpo Järvinen Date: Wed, 14 Nov 2007 05:03:13 +0000 (-0800) Subject: [TCP] FRTO: Plug potential LOST-bit leak X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=23aeeec365dcf8bc87fae44c533e50d0bb4f23cc;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git [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 . Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- 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 */