This is because only when in_sack is equal to false
the pkt_len can be greater than or equal to skb->len,
so checking the in_sack firstly will make the logic
more clear.

Signed-off-by: Xin Guo <guoxin0309@gmail.com>
---
 net/ipv4/tcp_input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 71b76e98371a..293fb2cc8969 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1375,7 +1375,7 @@ static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
 			pkt_len = new_len;
 		}
 
-		if (pkt_len >= skb->len && !in_sack)
+		if (!in_sack && pkt_len >= skb->len)
 			return 0;
 
 		err = tcp_fragment(sk, TCP_FRAG_IN_RTX_QUEUE, skb,
-- 
2.43.0