libpq was not consistently checking for memory allocation failures. This

patch adds missing checks to the call sites of malloc(), strdup(),
PQmakeEmptyPGresult(), pqResultAlloc(), and pqResultStrdup(), and updates
the documentation. Per original report from Volkan Yazici about
PQmakeEmptyPGresult() not checking for malloc() failure.

1 files changed, 41 insertions, 16 deletions

diff --git a/src/interfaces/libpq/fe-protocol2.c b/src/interfaces/libpq/fe-protocol2.c
index 2501ef4a603..b5753dba445 100644
--- a/src/interfaces/libpq/fe-protocol2.c
+++ b/src/interfaces/libpq/fe-protocol2.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-protocol2.c,v 1.17 2005/05/11 01:26:02 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-protocol2.c,v 1.18 2005/06/12 00:00:21 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -438,8 +438,12 @@ pqParseInput2(PGconn *conn)
 					if (pqGets(&conn->workBuffer, conn))
 						return;
 					if (conn->result == NULL)
+					{
 						conn->result = PQmakeEmptyPGresult(conn,
 													   PGRES_COMMAND_OK);
+						if (!conn->result)
+							return;
+					}
 					strncpy(conn->result->cmdStatus, conn->workBuffer.data,
 							CMDSTATUS_LEN);
 					checkXactStatus(conn, conn->workBuffer.data);
@@ -572,19 +576,18 @@ pqParseInput2(PGconn *conn)
 static int
 getRowDescriptions(PGconn *conn)
 {
-	PGresult   *result;
+	PGresult   *result = NULL;
 	int			nfields;
 	int			i;
 
 	result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
+	if (!result)
+		goto failure;
 
 	/* parseInput already read the 'T' label. */
 	/* the next two bytes are the number of fields	*/
 	if (pqGetInt(&(result->numAttributes), 2, conn))
-	{
-		PQclear(result);
-		return EOF;
-	}
+		goto failure;
 	nfields = result->numAttributes;
 
 	/* allocate space for the attribute descriptors */
@@ -592,6 +595,8 @@ getRowDescriptions(PGconn *conn)
 	{
 		result->attDescs = (PGresAttDesc *)
 			pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE);
+		if (!result->attDescs)
+			goto failure;
 		MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc));
 	}
 
@@ -606,10 +611,7 @@ getRowDescriptions(PGconn *conn)
 			pqGetInt(&typid, 4, conn) ||
 			pqGetInt(&typlen, 2, conn) ||
 			pqGetInt(&atttypmod, 4, conn))
-		{
-			PQclear(result);
-			return EOF;
-		}
+			goto failure;
 
 		/*
 		 * Since pqGetInt treats 2-byte integers as unsigned, we need to
@@ -619,6 +621,8 @@ getRowDescriptions(PGconn *conn)
 
 		result->attDescs[i].name = pqResultStrdup(result,
 												  conn->workBuffer.data);
+		if (!result->attDescs[i].name)
+			goto failure;
 		result->attDescs[i].tableid = 0;
 		result->attDescs[i].columnid = 0;
 		result->attDescs[i].format = 0;
@@ -630,6 +634,11 @@ getRowDescriptions(PGconn *conn)
 	/* Success! */
 	conn->result = result;
 	return 0;
+
+failure:
+	if (result)
+		PQclear(result);
+	return EOF;
 }
 
 /*
@@ -685,7 +694,11 @@ getAnotherTuple(PGconn *conn, bool binary)
 	nbytes = (nfields + BITS_PER_BYTE - 1) / BITS_PER_BYTE;
 	/* malloc() only for unusually large field counts... */
 	if (nbytes > sizeof(std_bitmap))
+	{
 		bitmap = (char *) malloc(nbytes);
+		if (!bitmap)
+			goto outOfMemory;
+	}
 
 	if (pqGetnchar(bitmap, nbytes, conn))
 		goto EOFexit;
@@ -758,13 +771,18 @@ outOfMemory:
 	pqClearAsyncResult(conn);
 	printfPQExpBuffer(&conn->errorMessage,
 					  libpq_gettext("out of memory for query result\n"));
+
+	/*
+	 * XXX: if PQmakeEmptyPGresult() fails, there's probably not much
+	 * we can do to recover...
+	 */
 	conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
 	conn->asyncStatus = PGASYNC_READY;
 	/* Discard the failed message --- good idea? */
 	conn->inStart = conn->inEnd;
 
 EOFexit:
-	if (bitmap != std_bitmap)
+	if (bitmap != NULL && bitmap != std_bitmap)
 		free(bitmap);
 	return EOF;
 }
@@ -780,7 +798,7 @@ EOFexit:
 static int
 pqGetErrorNotice2(PGconn *conn, bool isError)
 {
-	PGresult   *res;
+	PGresult   *res = NULL;
 	PQExpBufferData workBuf;
 	char	   *startp;
 	char	   *splitp;
@@ -792,10 +810,7 @@ pqGetErrorNotice2(PGconn *conn, bool isError)
 	 */
 	initPQExpBuffer(&workBuf);
 	if (pqGets(&workBuf, conn))
-	{
-		termPQExpBuffer(&workBuf);
-		return EOF;
-	}
+		goto failure;
 
 	/*
 	 * Make a PGresult to hold the message.  We temporarily lie about the
@@ -803,8 +818,12 @@ pqGetErrorNotice2(PGconn *conn, bool isError)
 	 * conn->errorMessage.
 	 */
 	res = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY);
+	if (!res)
+		goto failure;
 	res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR;
 	res->errMsg = pqResultStrdup(res, workBuf.data);
+	if (!res->errMsg)
+		goto failure;
 
 	/*
 	 * Break the message into fields.  We can't do very much here, but we
@@ -869,6 +888,12 @@ pqGetErrorNotice2(PGconn *conn, bool isError)
 
 	termPQExpBuffer(&workBuf);
 	return 0;
+
+failure:
+	if (res)
+		PQclear(res);
+	termPQExpBuffer(&workBuf);
+	return EOF;
 }
 
 /*