1 files changed, 5 insertions, 0 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 870f53afd363..c6109895bb5e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -998,6 +998,11 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
                 tp->recv_sack_cache[i].start_seq = start_seq;
                 tp->recv_sack_cache[i].end_seq = end_seq;
         }
+        /* Clear the rest of the cache sack blocks so they won't match mistakenly. */
+        for (; i < ARRAY_SIZE(tp->recv_sack_cache); i++) {
+                tp->recv_sack_cache[i].start_seq = 0;
+                tp->recv_sack_cache[i].end_seq = 0;
+        }
 
         first_sack_index = 0;
         if (flag)