Missing sanity checks for various C library function calls...

[Bill Parker <wp02855 at gmail dot com>]

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++) {

I am attaching the patch file to this email

Bill Parker (wp02855 at gmail dot com)

Attachment: ffi.c.patch
Description: Binary data