From 34588b4c046c34773e5a1a962da7b78b05c4d1bd Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Mon, 30 Apr 2007 00:57:33 -0700 Subject: [PATCH] [TCP]: Catch skb with S+L bugs earlier MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit SACKED_ACKED and LOST are mutually exclusive with SACK, thus having their sum larger than packets_out is bug with SACK. Eventually these bugs trigger traps in the tcp_clean_rtx_queue with SACK but it's much more informative to do this here. Non-SACK TCP, however, could get more than packets_out duplicate ACKs which each increment sacked_out, so it makes sense to do this kind of limitting for non-SACK TCP but not for SACK enabled one. Perhaps the author had the opposite in mind but did the logic accidently wrong way around? Anyway, the sacked_out incrementer code for non-SACK already deals this issue before calling sync_left_out so this trapping can be done unconditionally. Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- include/net/tcp.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index a385797f160a..c6ecd455edab 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -736,9 +736,7 @@ static inline __u32 tcp_current_ssthresh(const struct sock *sk) static inline void tcp_sync_left_out(struct tcp_sock *tp) { - if (tp->rx_opt.sack_ok && - (tp->sacked_out >= tp->packets_out - tp->lost_out)) - tp->sacked_out = tp->packets_out - tp->lost_out; + BUG_ON(tp->sacked_out + tp->lost_out > tp->packets_out); tp->left_out = tp->sacked_out + tp->lost_out; } -- 2.20.1