[New-bugs-announce] [issue23878] Missing sanity checks for various C library function calls...

[Bill Parker]

New submission from Bill Parker:

Hello All,

   In reviewing code for Python-3.4.3 in directory
'Modules/_ctypes/libffi/src/arm', file 'ffi.c', I found a pair
of calls to calloc() which do not test for a return value
of NULL, indicating failure.  The patch file below corrects
this issue:

--- ffi.c.orig  2015-04-04 15:43:19.662709073 -0700
+++ ffi.c       2015-04-04 15:51:27.142665269 -0700
@@ -629,12 +629,21 @@
 
     /* We have valid trampoline and config pages */
     table = calloc (1, sizeof(ffi_trampoline_table));
+    if (table == NULL) { /* oops, calloc() failed, now what??? */
+      fprintf(stderr, "vm calloc() failure: %d at %s:%d\n", kt, __FILE__, __LINE__);
+      return NULL; /* go home??? */
+    }
     table->free_count = FFI_TRAMPOLINE_COUNT;
     table->config_page = config_page;
     table->trampoline_page = trampoline_page;
 
     /* Create and initialize the free list */
     table->free_list_pool = calloc(FFI_TRAMPOLINE_COUNT, sizeof(ffi_trampoline_table_entry));
+    if (table->free_list_pool == NULL) { /* oops, calloc() failed, now what */
+      fprintf(stderr, "vm calloc() failure: %d at %s:%d\n", kt, __FILE__, __LINE__);
+      free(table);  /* free table (from previos calloc() call) */
+      return NULL;  /* go home??? *
+    }
 
     uint16_t i;
     for (i = 0; i < table->free_count; i++) {

In directory 'Modules', file 'getpath.c', I found a call to fseek()
which is not checked for a return value < 0, indicating failure.  The
patch file below corrects this issue:

--- getpath.c.orig      2015-04-04 16:07:25.540472702 -0700
+++ getpath.c   2015-04-04 16:09:30.988416490 -0700
@@ -265,7 +265,9 @@
     int result = 0; /* meaning not found */
     char buffer[MAXPATHLEN*2+1];  /* allow extra for key, '=', etc. */
 
-    fseek(env_file, 0, SEEK_SET);
+    if (fseek(env_file, 0, SEEK_SET) < 0)
+        return result;
+   
     while (!feof(env_file)) {
         char * p = fgets(buffer, MAXPATHLEN*2, env_file);
         wchar_t tmpbuffer[MAXPATHLEN*2+1];
		 		
I am attaching the patch file(s) to this bug report...

Bill Parker (wp02855 at gmail dot com)

----------
components: Interpreter Core
files: getpath.c.patch
keywords: patch
messages: 240160
nosy: dogbert2
priority: normal
severity: normal
status: open
title: Missing sanity checks for various C library function calls...
type: behavior
versions: Python 3.4
Added file: http://bugs.python.org/file38848/getpath.c.patch

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue23878>
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