[Python-checkins] r50585 - in python/branches/bcannon-sandboxing: Include/sandbox.h Python/sandbox.c

[brett.cannon]

Author: brett.cannon
Date: Tue Jul 11 20:46:19 2006
New Revision: 50585

Modified:
   python/branches/bcannon-sandboxing/Include/sandbox.h
   python/branches/bcannon-sandboxing/Python/sandbox.c
Log:
Switch to using size_t for memory tracking.  Also watch for integer overflow.


Modified: python/branches/bcannon-sandboxing/Include/sandbox.h
==============================================================================
--- python/branches/bcannon-sandboxing/Include/sandbox.h	(original)
+++ python/branches/bcannon-sandboxing/Include/sandbox.h	Tue Jul 11 20:46:19 2006
@@ -10,8 +10,8 @@
 
 typedef struct _sandbox_state {
     /* The memory cap and current usage. */
-    Py_ssize_t mem_cap;
-    Py_ssize_t mem_usage;
+    size_t mem_cap;
+    size_t mem_usage;
 
 } PySandboxState;
 

Modified: python/branches/bcannon-sandboxing/Python/sandbox.c
==============================================================================
--- python/branches/bcannon-sandboxing/Python/sandbox.c	(original)
+++ python/branches/bcannon-sandboxing/Python/sandbox.c	Tue Jul 11 20:46:19 2006
@@ -31,18 +31,19 @@
     PySandboxState *sandbox_state = _PySandbox_GET();
 
     if (_PySandbox_Check() && _PySandbox_IsMemCapped()) {
+	size_t orig_mem_usage = sandbox_state->mem_usage;
+
 	sandbox_state->mem_usage += allocate;
-	if (sandbox_state->mem_cap < sandbox_state->mem_usage) {
+	/* Watch out for integer overflow. */
+	if ((sandbox_state->mem_cap < sandbox_state->mem_usage) ||
+		(orig_mem_usage > sandbox_state->mem_usage)) {
 	    sandbox_state -= allocate;
 	    PyErr_SetString(PyExc_SandboxError, "memory allocation exceeded");
 	    return 0;
 	}
-	else
-	    return 1;
-	
     }
-    else
-	return 1;
+
+    return 1;
 }
 
 /*