diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3166dc1..60c3845 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1576,6 +1576,7 @@ struct tcp_md5sig_key {
 	u8			keylen;
 	u8			family; /* AF_INET or AF_INET6 */
 	u8			prefixlen;
+	u8			flags;
 	union tcp_md5_addr	addr;
 	int			l3index; /* set if key added with L3 scope */
 	u8			key[TCP_MD5SIG_MAXKEYLEN];
@@ -1621,10 +1622,10 @@ struct tcp_md5sig_pool {
 int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
 			const struct sock *sk, const struct sk_buff *skb);
 int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
-		   int family, u8 prefixlen, int l3index,
+		   int family, u8 prefixlen, int l3index, u8 flags,
 		   const u8 *newkey, u8 newkeylen, gfp_t gfp);
 int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr,
-		   int family, u8 prefixlen, int l3index);
+		   int family, u8 prefixlen, int l3index, u8 flags);
 struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
 					 const struct sock *addr_sk);
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f64b6c8..5b8ce65 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1073,7 +1073,7 @@ struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index,
 				 lockdep_sock_is_held(sk)) {
 		if (key->family != family)
 			continue;
-		if (key->l3index && key->l3index != l3index)
+		if (key->flags & TCP_MD5SIG_FLAG_IFINDEX && key->l3index != l3index)
 			continue;
 		if (family == AF_INET) {
 			mask = inet_make_mask(key->prefixlen);
@@ -1098,7 +1098,7 @@ EXPORT_SYMBOL(__tcp_md5_do_lookup);
 static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk,
 						      const union tcp_md5_addr *addr,
 						      int family, u8 prefixlen,
-						      int l3index)
+						      int l3index, u8 flags)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_key *key;
@@ -1118,6 +1118,8 @@ static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk,
 				 lockdep_sock_is_held(sk)) {
 		if (key->family != family)
 			continue;
+		if ((key->flags & TCP_MD5SIG_FLAG_IFINDEX) != (flags & TCP_MD5SIG_FLAG_IFINDEX))
+			continue;
 		if (key->l3index != l3index)
 			continue;
 		if (!memcmp(&key->addr, addr, size) &&
@@ -1142,7 +1144,7 @@ EXPORT_SYMBOL(tcp_v4_md5_lookup);
 
 /* This can be called on a newly created socket, from other files */
 int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
-		   int family, u8 prefixlen, int l3index,
+		   int family, u8 prefixlen, int l3index, u8 flags,
 		   const u8 *newkey, u8 newkeylen, gfp_t gfp)
 {
 	/* Add Key to the list */
@@ -1150,7 +1152,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_info *md5sig;
 
-	key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index);
+	key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags);
 	if (key) {
 		/* Pre-existing entry - just update that one.
 		 * Note that the key might be used concurrently.
@@ -1195,6 +1197,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 	key->family = family;
 	key->prefixlen = prefixlen;
 	key->l3index = l3index;
+	key->flags = flags;
 	memcpy(&key->addr, addr,
 	       (family == AF_INET6) ? sizeof(struct in6_addr) :
 				      sizeof(struct in_addr));
@@ -1204,11 +1207,11 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 EXPORT_SYMBOL(tcp_md5_do_add);
 
 int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family,
-		   u8 prefixlen, int l3index)
+		   u8 prefixlen, int l3index, u8 flags)
 {
 	struct tcp_md5sig_key *key;
 
-	key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index);
+	key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags);
 	if (!key)
 		return -ENOENT;
 	hlist_del_rcu(&key->node);
@@ -1242,6 +1245,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
 	const union tcp_md5_addr *addr;
 	u8 prefixlen = 32;
 	int l3index = 0;
+	u8 flags;
 
 	if (optlen < sizeof(cmd))
 		return -EINVAL;
@@ -1252,6 +1256,8 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
 	if (sin->sin_family != AF_INET)
 		return -EINVAL;
 
+	flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
+
 	if (optname == TCP_MD5SIG_EXT &&
 	    cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
 		prefixlen = cmd.tcpm_prefixlen;
@@ -1259,7 +1265,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
 			return -EINVAL;
 	}
 
-	if (optname == TCP_MD5SIG_EXT &&
+	if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
 	    cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
 		struct net_device *dev;
 
@@ -1280,12 +1286,12 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
 	addr = (union tcp_md5_addr *)&sin->sin_addr.s_addr;
 
 	if (!cmd.tcpm_keylen)
-		return tcp_md5_do_del(sk, addr, AF_INET, prefixlen, l3index);
+		return tcp_md5_do_del(sk, addr, AF_INET, prefixlen, l3index, flags);
 
 	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 		return -EINVAL;
 
-	return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index,
+	return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags,
 			      cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 }
 
@@ -1609,7 +1615,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 		 * memory, then we end up not copying the key
 		 * across. Shucks.
 		 */
-		tcp_md5_do_add(newsk, addr, AF_INET, 32, l3index,
+		tcp_md5_do_add(newsk, addr, AF_INET, 32, l3index, key->flags,
 			       key->key, key->keylen, GFP_ATOMIC);
 		sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
 	}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 0ce52d4..b03dd02 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -599,6 +599,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 	int l3index = 0;
 	u8 prefixlen;
+	u8 flags;
 
 	if (optlen < sizeof(cmd))
 		return -EINVAL;
@@ -609,6 +610,8 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
 	if (sin6->sin6_family != AF_INET6)
 		return -EINVAL;
 
+	flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
+
 	if (optname == TCP_MD5SIG_EXT &&
 	    cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
 		prefixlen = cmd.tcpm_prefixlen;
@@ -619,7 +622,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
 		prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
 	}
 
-	if (optname == TCP_MD5SIG_EXT &&
+	if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
 	    cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
 		struct net_device *dev;
 
@@ -640,9 +643,9 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
 		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 			return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 					      AF_INET, prefixlen,
-					      l3index);
+					      l3index, flags);
 		return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
-				      AF_INET6, prefixlen, l3index);
+				      AF_INET6, prefixlen, l3index, flags);
 	}
 
 	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
@@ -650,12 +653,12 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
 
 	if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 		return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
-				      AF_INET, prefixlen, l3index,
+				      AF_INET, prefixlen, l3index, flags,
 				      cmd.tcpm_key, cmd.tcpm_keylen,
 				      GFP_KERNEL);
 
 	return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
-			      AF_INET6, prefixlen, l3index,
+			      AF_INET6, prefixlen, l3index, flags,
 			      cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 }
 
@@ -1404,7 +1407,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
 		 * across. Shucks.
 		 */
 		tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
-			       AF_INET6, 128, l3index, key->key, key->keylen,
+			       AF_INET6, 128, l3index, key->flags, key->key, key->keylen,
 			       sk_gfp_mask(sk, GFP_ATOMIC));
 	}
 #endif