[PATCH 2/5] Correctly free config file names

[przanoni at gmail.com]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

We call xf86penConfigDirFiles twice, so we overwrite the configDirPath
variable, losing the pointer. If we move the pointer management to the
upper layer (the function callers), they will be able to call these
functions as many times as they want, but they'll have to free those
returned values.

4,097 bytes in 1 blocks are definitely lost in loss record 625 of 632
   at 0x4C2779D: malloc (in vgpreload_memcheck-amd64-linux.so)
   by 0x4D7899: DoSubstitution (scan.c:615)
   by 0x4D87B0: OpenConfigDir (scan.c:845)
   by 0x4D8A2D: xf86openConfigDirFiles (scan.c:955)
   by 0x49031F: xf86HandleConfigFile (xf86Config.c:2327)
   by 0x49A9BF: InitOutput (xf86Init.c:365)
   by 0x425A7A: main (main.c:204)

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 hw/xfree86/common/xf86Config.c |    6 +++++-
 hw/xfree86/parser/scan.c       |   22 ++++++++--------------
 hw/xfree86/parser/xf86Parser.h |    8 ++++----
 3 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/hw/xfree86/common/xf86Config.c b/hw/xfree86/common/xf86Config.c
index cb4be42..5ab3e67 100644
--- a/hw/xfree86/common/xf86Config.c
+++ b/hw/xfree86/common/xf86Config.c
@@ -2301,7 +2301,7 @@ checkInput(serverLayoutPtr layout, Bool implicit_layout) {
 ConfigStatus
 xf86HandleConfigFile(Bool autoconfig)
 {
-    const char *filename, *dirname, *sysdirname;
+    char *filename, *dirname, *sysdirname;
     char *filesearch, *dirsearch;
     MessageType filefrom = X_DEFAULT;
     MessageType dirfrom = X_DEFAULT;
@@ -2353,6 +2353,10 @@ xf86HandleConfigFile(Bool autoconfig)
 	    return CONFIG_NOFILE;
     }
 
+    free(filename);
+    free(dirname);
+    free(sysdirname);
+
     if ((xf86configptr = xf86readConfigFile ()) == NULL) {
 	xf86Msg(X_ERROR, "Problem parsing the config file\n");
 	return CONFIG_PARSE_ERROR;
diff --git a/hw/xfree86/parser/scan.c b/hw/xfree86/parser/scan.c
index 99b3257..668237b 100644
--- a/hw/xfree86/parser/scan.c
+++ b/hw/xfree86/parser/scan.c
@@ -101,8 +101,6 @@ static int builtinIndex = 0;
 static int configPos = 0;		/* current readers position */
 static int configLineNo = 0;	/* linenumber */
 static char *configBuf, *configRBuf;	/* buffer for lines */
-static char *configPath;		/* path to config file */
-static char *configDirPath;		/* path to config dir */
 static char *configSection = NULL;	/* name of current section being parsed */
 static int numFiles = 0;		/* number of config files */
 static int curFileIndex = 0;		/* index of current config file */
@@ -892,7 +890,8 @@ xf86initConfigFiles(void)
  * of the located files.
  *
  * The return value is a pointer to the actual name of the file that was
- * opened.  When no file is found, the return value is NULL.
+ * opened.  When no file is found, the return value is NULL. The caller should
+ * free() the returned value.
  *
  * The escape sequences allowed in the search path are defined above.
  *
@@ -914,7 +913,7 @@ xf86initConfigFiles(void)
 							"%P/lib/X11/%X"
 #endif
 
-const char *
+char *
 xf86openConfigFile(const char *path, const char *cmdline, const char *projroot)
 {
 	if (!path || !path[0])
@@ -923,8 +922,7 @@ xf86openConfigFile(const char *path, const char *cmdline, const char *projroot)
 		projroot = PROJECTROOT;
 
 	/* Search for a config file */
-	configPath = OpenConfigFile(path, cmdline, projroot, XCONFIGFILE);
-	return configPath;
+	return OpenConfigFile(path, cmdline, projroot, XCONFIGFILE);
 }
 
 /*
@@ -937,12 +935,13 @@ xf86openConfigFile(const char *path, const char *cmdline, const char *projroot)
  * fails if it is not found.
  *
  * The return value is a pointer to the actual name of the direcoty that was
- * opened.  When no directory is found, the return value is NULL.
+ * opened.  When no directory is found, the return value is NULL. The caller
+ * should free() the returned value.
  *
  * The escape sequences allowed in the search path are defined above.
  *
  */
-const char *
+char *
 xf86openConfigDirFiles(const char *path, const char *cmdline,
 		       const char *projroot)
 {
@@ -952,8 +951,7 @@ xf86openConfigDirFiles(const char *path, const char *cmdline,
 		projroot = PROJECTROOT;
 
 	/* Search for the multiconf directory */
-	configDirPath = OpenConfigDir(path, cmdline, projroot, XCONFIGDIR);
-	return configDirPath;
+	return OpenConfigDir(path, cmdline, projroot, XCONFIGDIR);
 }
 
 void
@@ -961,10 +959,6 @@ xf86closeConfigFile (void)
 {
 	int i;
 
-	free (configPath);
-	configPath = NULL;
-	free (configDirPath);
-	configDirPath = NULL;
 	free (configRBuf);
 	configRBuf = NULL;
 	free (configBuf);
diff --git a/hw/xfree86/parser/xf86Parser.h b/hw/xfree86/parser/xf86Parser.h
index a8785c5..c31fdc4 100644
--- a/hw/xfree86/parser/xf86Parser.h
+++ b/hw/xfree86/parser/xf86Parser.h
@@ -487,10 +487,10 @@ xf86ConfigSymTabRec, *xf86ConfigSymTabPtr;
  * prototypes for public functions
  */
 extern void xf86initConfigFiles(void);
-extern const char *xf86openConfigFile(const char *path, const char *cmdline,
-				      const char *projroot);
-extern const char *xf86openConfigDirFiles(const char *path, const char *cmdline,
-					  const char *projroot);
+extern char *xf86openConfigFile(const char *path, const char *cmdline,
+				const char *projroot);
+extern char *xf86openConfigDirFiles(const char *path, const char *cmdline,
+				    const char *projroot);
 extern void xf86setBuiltinConfig(const char *config[]);
 extern XF86ConfigPtr xf86readConfigFile(void);
 extern void xf86closeConfigFile(void);
-- 
1.7.7