The mentioned MIB is currently incremented even when a packet with an old sequence number (i.e. a zero window probe) is received, which is IMHO misleading. Explicitly restrict such MIB increment at the relevant events. Fixes: 6c758062c64d ("tcp: add LINUX_MIB_BEYOND_WINDOW") Acked-by: Eric Dumazet Signed-off-by: Paolo Abeni --- net/ipv4/tcp_input.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 81b6d3770812..71b76e98371a 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5915,7 +5915,11 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb, if (!th->rst) { if (th->syn) goto syn_challenge; - NET_INC_STATS(sock_net(sk), LINUX_MIB_BEYOND_WINDOW); + + if (reason == SKB_DROP_REASON_TCP_INVALID_SEQUENCE || + reason == SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE) + NET_INC_STATS(sock_net(sk), + LINUX_MIB_BEYOND_WINDOW); if (!tcp_oow_rate_limited(sock_net(sk), skb, LINUX_MIB_TCPACKSKIPPEDSEQ, &tp->last_oow_ack_time)) -- 2.50.0