diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c
index 4c86fb6087..3a78d2043e 100644
--- a/src/backend/libpq/hba.c
+++ b/src/backend/libpq/hba.c
@@ -1188,8 +1188,11 @@ parse_hba_line(TokenizedLine *tok_line, int elevel)
 
 			ret = pg_getaddrinfo_all(str, NULL, &hints, &gai_result);
 			if (ret == 0 && gai_result)
+			{
 				memcpy(&parsedline->addr, gai_result->ai_addr,
 					   gai_result->ai_addrlen);
+				parsedline->addrlen = gai_result->ai_addrlen;
+			}
 			else if (ret == EAI_NONAME)
 				parsedline->hostname = str;
 			else
@@ -1238,6 +1241,7 @@ parse_hba_line(TokenizedLine *tok_line, int elevel)
 										token->string);
 					return NULL;
 				}
+				parsedline->masklen = parsedline->addrlen;
 				pfree(str);
 			}
 			else if (!parsedline->hostname)
@@ -1288,6 +1292,7 @@ parse_hba_line(TokenizedLine *tok_line, int elevel)
 
 				memcpy(&parsedline->mask, gai_result->ai_addr,
 					   gai_result->ai_addrlen);
+				parsedline->masklen = gai_result->ai_addrlen;
 				pg_freeaddrinfo_all(hints.ai_family, gai_result);
 
 				if (parsedline->addr.ss_family != parsedline->mask.ss_family)
@@ -2538,20 +2543,26 @@ fill_hba_line(Tuplestorestate *tuple_store, TupleDesc tupdesc,
 				}
 				else
 				{
-					if (pg_getnameinfo_all(&hba->addr, sizeof(hba->addr),
-										   buffer, sizeof(buffer),
-										   NULL, 0,
-										   NI_NUMERICHOST) == 0)
+					/*
+					 * Note: if pg_getnameinfo_all fails, it'll set buffer to
+					 * "???", which we want to return.
+					 */
+					if (hba->addrlen > 0)
 					{
-						clean_ipv6_addr(hba->addr.ss_family, buffer);
+						if (pg_getnameinfo_all(&hba->addr, hba->addrlen,
+											   buffer, sizeof(buffer),
+											   NULL, 0,
+											   NI_NUMERICHOST) == 0)
+							clean_ipv6_addr(hba->addr.ss_family, buffer);
 						addrstr = pstrdup(buffer);
 					}
-					if (pg_getnameinfo_all(&hba->mask, sizeof(hba->mask),
-										   buffer, sizeof(buffer),
-										   NULL, 0,
-										   NI_NUMERICHOST) == 0)
+					if (hba->masklen > 0)
 					{
-						clean_ipv6_addr(hba->mask.ss_family, buffer);
+						if (pg_getnameinfo_all(&hba->mask, hba->masklen,
+											   buffer, sizeof(buffer),
+											   NULL, 0,
+											   NI_NUMERICHOST) == 0)
+							clean_ipv6_addr(hba->mask.ss_family, buffer);
 						maskstr = pstrdup(buffer);
 					}
 				}
diff --git a/src/include/libpq/hba.h b/src/include/libpq/hba.h
index d638479d88..8f09b5638f 100644
--- a/src/include/libpq/hba.h
+++ b/src/include/libpq/hba.h
@@ -42,6 +42,10 @@ typedef enum UserAuth
 #define USER_AUTH_LAST uaPeer	/* Must be last value of this enum */
 } UserAuth;
 
+/*
+ * Data structures representing pg_hba.conf entries
+ */
+
 typedef enum IPCompareMethod
 {
 	ipCmpMask,
@@ -75,11 +79,12 @@ typedef struct HbaLine
 	List	   *databases;
 	List	   *roles;
 	struct sockaddr_storage addr;
+	int			addrlen;		/* zero if we don't have a valid addr */
 	struct sockaddr_storage mask;
+	int			masklen;		/* zero if we don't have a valid mask */
 	IPCompareMethod ip_cmp_method;
 	char	   *hostname;
 	UserAuth	auth_method;
-
 	char	   *usermap;
 	char	   *pamservice;
 	bool		pam_use_hostname;