diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 3474514adc..32994f11a9 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -196,6 +196,7 @@ WalReceiverMain(void)
 	bool		first_stream;
 	WalRcvData *walrcv = WalRcv;
 	TimestampTz last_recv_timestamp;
+	TimestampTz current_timestamp;
 	bool		ping_sent;
 	char	   *err;
 
@@ -205,6 +206,12 @@ WalReceiverMain(void)
 	 */
 	Assert(walrcv != NULL);
 
+	/*
+	 * Acquire timestamp before acquiring the WAL receiver spin lock.
+	 * External calls should not happen in such sections.
+	 */
+	current_timestamp = GetCurrentTimestamp();
+
 	/*
 	 * Mark walreceiver as running in shared memory.
 	 *
@@ -234,6 +241,7 @@ WalReceiverMain(void)
 		case WALRCV_STREAMING:
 		case WALRCV_RESTARTING:
 		default:
+			SpinLockRelease(&walrcv->mutex);
 			/* Shouldn't happen */
 			elog(PANIC, "walreceiver still running according to shared memory state");
 	}
@@ -249,7 +257,7 @@ WalReceiverMain(void)
 	startpointTLI = walrcv->receiveStartTLI;
 
 	/* Initialise to a sanish value */
-	walrcv->lastMsgSendTime = walrcv->lastMsgReceiptTime = walrcv->latestWalEndTime = GetCurrentTimestamp();
+	walrcv->lastMsgSendTime = walrcv->lastMsgReceiptTime = walrcv->latestWalEndTime = current_timestamp;
 
 	SpinLockRelease(&walrcv->mutex);
 
@@ -308,13 +316,13 @@ WalReceiverMain(void)
 	SpinLockAcquire(&walrcv->mutex);
 	memset(walrcv->conninfo, 0, MAXCONNINFO);
 	if (tmp_conninfo)
-	{
 		strlcpy((char *) walrcv->conninfo, tmp_conninfo, MAXCONNINFO);
-		pfree(tmp_conninfo);
-	}
 	walrcv->ready_to_display = true;
 	SpinLockRelease(&walrcv->mutex);
 
+	if (tmp_conninfo)
+		pfree(tmp_conninfo);
+
 	first_stream = true;
 	for (;;)
 	{
@@ -1393,6 +1401,9 @@ pg_stat_get_wal_receiver(PG_FUNCTION_ARGS)
 	char	   *slotname;
 	char	   *conninfo;
 
+	slotname = (char *) palloc(NAMEDATALEN);
+	conninfo = (char *) palloc(MAXCONNINFO);
+
 	/* Take a lock to ensure value consistency */
 	SpinLockAcquire(&WalRcv->mutex);
 	pid = (int) WalRcv->pid;
@@ -1406,8 +1417,8 @@ pg_stat_get_wal_receiver(PG_FUNCTION_ARGS)
 	last_receipt_time = WalRcv->lastMsgReceiptTime;
 	latest_end_lsn = WalRcv->latestWalEnd;
 	latest_end_time = WalRcv->latestWalEndTime;
-	slotname = pstrdup(WalRcv->slotname);
-	conninfo = pstrdup(WalRcv->conninfo);
+	memcpy(slotname, WalRcv->slotname, NAMEDATALEN);
+	memcpy(conninfo, WalRcv->conninfo, MAXCONNINFO);
 	SpinLockRelease(&WalRcv->mutex);
 
 	/*