xfree86: parser: check for alloc failure and possible NULL pointers

Adding paranoid extra checks against allocation failure and NULL pointers.
Even though might not be actually hit in practise, it's still better to
be cautious, just in case. And reducing analyzer noise this way.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

hw/xfree86/parser/Files.c

@@ -55,6 +55,8 @@
 #include <xorg-config.h>
 #endif
 
+#include <assert.h>
+
 #include <X11/Xos.h>
 #include "xf86Parser.h"
 #include "xf86tokens.h"
@@ -109,9 +111,9 @@ xf86parseFilesSection(void)
                 }
             }
             ptr->file_fontpath = realloc(ptr->file_fontpath, i);
+            assert(ptr->file_fontpath);
             if (j)
                 strcat(ptr->file_fontpath, ",");
-
             strcat(ptr->file_fontpath, str);
             free(xf86_lex_val.str);
             break;
@@ -121,7 +123,8 @@ xf86parseFilesSection(void)
             l = FALSE;
             str = xf86_lex_val.str;
             if (ptr->file_modulepath == NULL) {
-                ptr->file_modulepath = malloc(1);
+                ptr->file_modulepath = calloc(1, 1);
+                assert(ptr->file_modulepath);
                 ptr->file_modulepath[0] = '\0';
                 k = strlen(str) + 1;
             }
@@ -134,6 +137,7 @@ xf86parseFilesSection(void)
                 }
             }
             ptr->file_modulepath = realloc(ptr->file_modulepath, k);
+            assert(ptr->file_modulepath);
             if (l)
                 strcat(ptr->file_modulepath, ",");
 

hw/xfree86/parser/Flags.c

@@ -55,6 +55,8 @@
 #include <xorg-config.h>
 #endif
 
+#include <assert.h>
+
 #include "xf86Parser.h"
 #include "xf86tokens.h"
 #include "Configint.h"
@@ -200,6 +202,7 @@ addNewOption2(XF86OptionPtr head, char *name, char *_val, int used)
     }
     else
         new = calloc(1, sizeof(*new));
+    assert(new);
     new->opt_name = name;
     new->opt_val = _val;
     new->opt_used = used;
@@ -437,6 +440,7 @@ xf86parseOption(XF86OptionPtr head)
     name = xf86_lex_val.str;
     if ((token = xf86getSubToken(&comment)) == STRING) {
         option = xf86newOption(name, xf86_lex_val.str);
+        assert(option);
         option->opt_comment = comment;
         if ((token = xf86getToken(NULL)) == COMMENT) {
             option->opt_comment = xf86addComment(option->opt_comment, xf86_lex_val.str);
@@ -448,6 +452,7 @@ xf86parseOption(XF86OptionPtr head)
     }
     else {
         option = xf86newOption(name, NULL);
+        assert(option);
         option->opt_comment = comment;
         if (token == COMMENT) {
             option->opt_comment = xf86addComment(option->opt_comment, xf86_lex_val.str);

hw/xfree86/parser/Layout.c

@@ -450,9 +450,9 @@ xf86layoutAddInputDevices(XF86ConfigPtr config, XF86ConfLayoutPtr layout)
             }
 
             if (!iref) {
-                XF86ConfInputrefPtr iptr;
+                XF86ConfInputrefPtr iptr = calloc(1, sizeof(XF86ConfInputrefRec));
-
+                if (!iptr)
-                iptr = calloc(1, sizeof(XF86ConfInputrefRec));
+                    return -1;
                 iptr->iref_inputdev_str = input->inp_identifier;
                 layout->lay_input_lst = (XF86ConfInputrefPtr)
                     xf86addListItem((glp) layout->lay_input_lst, (glp) iptr);

hw/xfree86/parser/Module.c

@@ -56,6 +56,8 @@
 #include <xorg-config.h>
 #endif
 
+#include <assert.h>
+
 #include "xf86Parser.h"
 #include "xf86tokens.h"
 #include "Configint.h"
@@ -228,6 +230,7 @@ xf86addNewLoadDirective(XF86LoadPtr head, const char *name, int type,
     int token;
 
     new = calloc(1, sizeof(XF86LoadRec));
+    assert(new);
     new->load_name = name;
     new->load_type = type;
     new->load_opt = opts;

hw/xfree86/parser/OutputClass.c

@@ -58,9 +58,12 @@ xf86freeOutputClassList(XF86ConfOutputClassPtr ptr)
 
         xorg_list_for_each_entry_safe(group, next, &ptr->match_driver, entry) {
             xorg_list_del(&group->entry);
-            for (list = group->values; *list; list++)
+            for (list = group->values; *list; list++) {
                 free(*list);
+                *list = NULL;
+            }
             free(group);
+            group = NULL;
         }
 
         xf86optionListFree(ptr->option_lst);

hw/xfree86/parser/scan.c

@@ -569,7 +569,6 @@ static char *
 DoSubstitution(const char *template, const char *cmdline, const char *projroot,
                int *cmdlineUsed, int *envUsed, const char *XConfigFile)
 {
-    char *result;
     int i, l;
     static const char *env = NULL;
     static char *hostname = NULL;
@@ -582,7 +581,10 @@ DoSubstitution(const char *template, const char *cmdline, const char *projroot,
     if (envUsed)
         *envUsed = 0;
 
-    result = malloc(PATH_MAX + 1);
+    char *result = calloc(1, PATH_MAX + 1);
+    if (!result)
+        return NULL;
+
     l = 0;
     for (i = 0; template[i]; i++) {
         if (template[i] != '%') {