diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index b71c22475c51..3ab6247be585 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -748,6 +748,7 @@ config TCP_SIGPOOL
 config TCP_AO
 	bool "TCP: Authentication Option (RFC5925)"
 	select CRYPTO
+	select CRYPTO_LIB_UTILS
 	select TCP_SIGPOOL
 	depends on 64BIT && IPV6 != m # seq-number extension needs WRITE_ONCE(u64)
 	help
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 4980caddb0fc..a97cdf3e6af4 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -10,6 +10,7 @@
 #define pr_fmt(fmt) "TCP: " fmt
 
 #include <crypto/hash.h>
+#include <crypto/utils.h>
 #include <linux/inetdevice.h>
 #include <linux/tcp.h>
 
@@ -922,7 +923,7 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
 	/* XXX: make it per-AF callback? */
 	tcp_ao_hash_skb(family, hash_buf, key, sk, skb, traffic_key,
 			(phash - (u8 *)th), sne);
-	if (memcmp(phash, hash_buf, maclen)) {
+	if (crypto_memneq(phash, hash_buf, maclen)) {
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
 		atomic64_inc(&info->counters.pkt_bad);
 		atomic64_inc(&key->pkt_bad);