Fix memory and file descriptor leaks in pg_receivexlog/pg_basebackup

When the internal loop mode was added, freeing memory and closing
filedescriptors before returning became important, and a few cases
in the code missed that.

Fujii Masao

Author: mhagander

src/bin/pg_basebackup/receivelog.c

@@ -38,6 +38,10 @@
 #define STREAMING_HEADER_SIZE (1+sizeof(WalDataMessageHeader))
 #define STREAMING_KEEPALIVE_SIZE (1+sizeof(PrimaryKeepaliveMessage))
 
+/* fd for currently open WAL file */
+static int		walfile = -1;
+
+
 /*
  * Open a new WAL file in the specified directory. Store the name
  * (not including the full directory) in namebuf. Assumes there is
@@ -96,6 +100,7 @@ open_walfile(XLogRecPtr startpoint, uint32 timeline, char *basedir, char *namebu
 		{
 			fprintf(stderr, _("%s: could not pad WAL segment %s: %s\n"),
 					progname, fn, strerror(errno));
+			free(zerobuf);
 			close(f);
 			unlink(fn);
 			return -1;
@@ -120,7 +125,7 @@ open_walfile(XLogRecPtr startpoint, uint32 timeline, char *basedir, char *namebu
  * completed writing the whole segment.
  */
 static bool
-close_walfile(int walfile, char *basedir, char *walname, bool segment_complete)
+close_walfile(char *basedir, char *walname, bool segment_complete)
 {
 	off_t		currpos = lseek(walfile, 0, SEEK_CUR);
 
@@ -142,8 +147,10 @@ close_walfile(int walfile, char *basedir, char *walname, bool segment_complete)
 	{
 		fprintf(stderr, _("%s: could not close file %s: %s\n"),
 				progname, walname, strerror(errno));
+		walfile = -1;
 		return false;
 	}
+	walfile = -1;
 
 	/*
 	 * Rename the .partial file only if we've completed writing the whole
@@ -270,7 +277,6 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 	char		current_walfile_name[MAXPGPATH];
 	PGresult   *res;
 	char	   *copybuf = NULL;
-	int			walfile = -1;
 	int64		last_status = -1;
 	XLogRecPtr	blockpos = InvalidXLogRecPtr;
 
@@ -315,6 +321,7 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 	{
 		fprintf(stderr, _("%s: could not start replication: %s\n"),
 				progname, PQresultErrorMessage(res));
+		PQclear(res);
 		return false;
 	}
 	PQclear(res);
@@ -341,9 +348,9 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 		 */
 		if (stream_stop && stream_stop(blockpos, timeline, false))
 		{
-			if (walfile != -1)
+			if (walfile != -1 && !close_walfile(basedir, current_walfile_name, rename_partial))
 				/* Potential error message is written by close_walfile */
-				return close_walfile(walfile, basedir, current_walfile_name, rename_partial);
+				goto error;
 			return true;
 		}
 
@@ -370,7 +377,7 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 			{
 				fprintf(stderr, _("%s: could not send feedback packet: %s"),
 						progname, PQerrorMessage(conn));
-				return false;
+				goto error;
 			}
 
 			last_status = now;
@@ -421,14 +428,14 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 			{
 				fprintf(stderr, _("%s: select() failed: %s\n"),
 						progname, strerror(errno));
-				return false;
+				goto error;
 			}
 			/* Else there is actually data on the socket */
 			if (PQconsumeInput(conn) == 0)
 			{
 				fprintf(stderr, _("%s: could not receive data from WAL stream: %s\n"),
 						progname, PQerrorMessage(conn));
-				return false;
+				goto error;
 			}
 			continue;
 		}
@@ -439,7 +446,7 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 		{
 			fprintf(stderr, _("%s: could not read copy data: %s\n"),
 					progname, PQerrorMessage(conn));
-			return false;
+			goto error;
 		}
 		if (copybuf[0] == 'k')
 		{
@@ -451,21 +458,21 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 			{
 				fprintf(stderr, _("%s: keepalive message is incorrect size: %d\n"),
 						progname, r);
-				return false;
+				goto error;
 			}
 			continue;
 		}
 		else if (copybuf[0] != 'w')
 		{
 			fprintf(stderr, _("%s: unrecognized streaming header: \"%c\"\n"),
 					progname, copybuf[0]);
-			return false;
+			goto error;
 		}
 		if (r < STREAMING_HEADER_SIZE + 1)
 		{
 			fprintf(stderr, _("%s: streaming header too small: %d\n"),
 					progname, r);
-			return false;
+			goto error;
 		}
 
 		/* Extract WAL location for this block */
@@ -483,7 +490,7 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 			{
 				fprintf(stderr, _("%s: received xlog record for offset %u with no file open\n"),
 						progname, xlogoff);
-				return false;
+				goto error;
 			}
 		}
 		else
@@ -494,7 +501,7 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 			{
 				fprintf(stderr, _("%s: got WAL data offset %08x, expected %08x\n"),
 						progname, xlogoff, (int) lseek(walfile, 0, SEEK_CUR));
-				return false;
+				goto error;
 			}
 		}
 
@@ -520,7 +527,7 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 									   basedir, current_walfile_name);
 				if (walfile == -1)
 					/* Error logged by open_walfile */
-					return false;
+					goto error;
 			}
 
 			if (write(walfile,
@@ -532,7 +539,7 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 						bytes_to_write,
 						current_walfile_name,
 						strerror(errno));
-				return false;
+				goto error;
 			}
 
 			/* Write was successful, advance our position */
@@ -544,11 +551,10 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 			/* Did we reach the end of a WAL segment? */
 			if (blockpos % XLOG_SEG_SIZE == 0)
 			{
-				if (!close_walfile(walfile, basedir, current_walfile_name, false))
+				if (!close_walfile(basedir, current_walfile_name, false))
 					/* Error message written in close_walfile() */
-					return false;
+					goto error;
 
-				walfile = -1;
 				xlogoff = 0;
 
 				if (stream_stop != NULL)
@@ -577,8 +583,22 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
 	{
 		fprintf(stderr, _("%s: unexpected termination of replication stream: %s\n"),
 				progname, PQresultErrorMessage(res));
-		return false;
+		goto error;
 	}
 	PQclear(res);
+
+	if (copybuf != NULL)
+		PQfreemem(copybuf);
+	if (walfile != -1 && close(walfile) != 0)
+		fprintf(stderr, _("%s: could not close file %s: %s\n"),
+				progname, current_walfile_name, strerror(errno));
 	return true;
+
+error:
+	if (copybuf != NULL)
+		PQfreemem(copybuf);
+	if (walfile != -1 && close(walfile) != 0)
+		fprintf(stderr, _("%s: could not close file %s: %s\n"),
+				progname, current_walfile_name, strerror(errno));
+	return false;
 }

src/bin/pg_basebackup/streamutil.c

@@ -143,6 +143,17 @@ GetConnection(void)
 
 		tmpconn = PQconnectdbParams(keywords, values, true);
 
+		/*
+		 * If there is too little memory even to allocate the PGconn object
+		 * and PQconnectdbParams returns NULL, we call exit(1) directly.
+		 */
+		if (!tmpconn)
+		{
+			fprintf(stderr, _("%s: could not connect to server\n"),
+					progname);
+			exit(1);
+		}
+
 		if (PQstatus(tmpconn) == CONNECTION_BAD &&
 			PQconnectionNeedsPassword(tmpconn) &&
 			dbgetpassword != -1)
@@ -154,8 +165,11 @@ GetConnection(void)
 
 		if (PQstatus(tmpconn) != CONNECTION_OK)
 		{
-			fprintf(stderr, _("%s: could not connect to server: %s"),
+			fprintf(stderr, _("%s: could not connect to server: %s\n"),
 					progname, PQerrorMessage(tmpconn));
+			PQfinish(tmpconn);
+			free(values);
+			free(keywords);
 			return NULL;
 		}