tcp_metrics: fix addr_same() helper

[ Upstream commit e6638094d7 ]

Because v4 and v6 families use separate inetpeer trees (respectively
net->ipv4.peers and net->ipv6.peers), inetpeer_addr_cmp(a, b) assumes
a & b share the same family.

tcp_metrics use a common hash table, where entries can have different
families.

We must therefore make sure to not call inetpeer_addr_cmp()
if the families do not match.

Fixes: d39d14ffa2 ("net: Add helper function to compare inetpeer addresses")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230802131500.1478140-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

net/ipv4/tcp_metrics.c

@@ -78,7 +78,7 @@ static void tcp_metric_set(struct tcp_metrics_block *tm,
 static bool addr_same(const struct inetpeer_addr *a,
 		      const struct inetpeer_addr *b)
 {
-	return inetpeer_addr_cmp(a, b) == 0;
+	return (a->family == b->family) && !inetpeer_addr_cmp(a, b);
 }
 
 struct tcpm_hash_bucket {