978384 - possible memory leak while realocking extend.c:1364

commit 55605ee3452aef5aabe4ed15a83374a97728e64a
Author: Jan Safranek <jsafranek@users.sourceforge.net>
Date:   Wed Jan 9 09:26:56 2013 +0100

    Fixed memory leak on failed realloc.

diff -up net-snmp-5.7.2/agent/mibgroup/agent/extend.c.orig net-snmp-5.7.2/agent/mibgroup/agent/extend.c
--- net-snmp-5.7.2/agent/mibgroup/agent/extend.c.orig	2013-06-26 15:50:15.000000000 +0200
+++ net-snmp-5.7.2/agent/mibgroup/agent/extend.c	2013-06-26 15:55:09.839899740 +0200
@@ -1457,17 +1457,26 @@ handle_nsExtendOutput2Table(netsnmp_mib_
 char * _get_cmdline(netsnmp_extend *extend)
 {
     size_t          size;
+    char           *args = extend->args;
+    char           *newbuf;
+   
+    if (args == NULL)
+        /* Use empty string for processes without arguments. */
+        args = "";
     
     size = strlen(extend->command) + strlen(extend->args) + 2;
     if (size > cmdlinesize) {
-        cmdlinebuf = realloc(cmdlinebuf, size);
-	if (!cmdlinebuf) {
+        newbuf = realloc(cmdlinebuf, size);
+	if (!newbuf) {
+            free(cmdlinebuf);
+            cmdlinebuf = NULL;
             cmdlinesize = 0;
             return NULL;
-	}
-	cmdlinesize = size;
+        }
+        cmdlinesize = size;
+        cmdlinebuf = newbuf;
     }
-    sprintf(cmdlinebuf, "%s %s", extend->command, extend->args);
+    sprintf(cmdlinebuf, "%s %s", extend->command, args);
     return cmdlinebuf;
 }