Protect GlobalHandle() against bad parameters.

oldstable
Lawson Whitney 2000-10-02 22:27:37 +00:00 committed by Alexandre Julliard
parent df12a0d654
commit 969515d07d
1 changed files with 52 additions and 23 deletions

View File

@ -13,6 +13,7 @@
#include <string.h>
#include "wine/winbase16.h"
#include "wine/exception.h"
#include "global.h"
#include "heap.h"
#include "toolhelp.h"
@ -54,6 +55,21 @@ static int globalArenaSize = 0;
#define VALID_HANDLE(handle) (((handle)>>__AHSHIFT)<globalArenaSize)
#define GET_ARENA_PTR(handle) (pGlobalArena + ((handle) >> __AHSHIFT))
/* filter for page-fault exceptions */
/* It is possible for a bogus global pointer to cause a */
/* page zero reference, so I include EXCEPTION_PRIV_INSTRUCTION too. */
static WINE_EXCEPTION_FILTER(page_fault)
{
switch (GetExceptionCode()) {
case (EXCEPTION_ACCESS_VIOLATION):
case (EXCEPTION_PRIV_INSTRUCTION):
return EXCEPTION_EXECUTE_HANDLER;
default:
return EXCEPTION_CONTINUE_SEARCH;
}
}
/***********************************************************************
* GLOBAL_GetArena
*
@ -1151,34 +1167,47 @@ HGLOBAL WINAPI GlobalHandle(
if (!pmem)
{
SetLastError( ERROR_INVALID_PARAMETER );
return 0;
SetLastError( ERROR_INVALID_PARAMETER );
return 0;
}
/* note that if pmem is a pointer to a a block allocated by */
/* GlobalAlloc with GMEM_MOVEABLE then magic test in HeapValidate */
/* will fail. */
if (ISPOINTER(pmem)) {
heap = GLOBAL_GetHeap( (HGLOBAL)pmem );
if (HeapValidate( heap, 0, pmem ))
return (HGLOBAL)pmem; /* valid fixed block */
handle = POINTER_TO_HANDLE(pmem);
} else
handle = (HGLOBAL)pmem;
__TRY
{
handle = 0;
/* Now test handle either passed in or retrieved from pointer */
heap = GLOBAL_GetHeap( handle );
maybe_intern = HANDLE_TO_INTERN( handle );
if (maybe_intern->Magic == MAGIC_GLOBAL_USED) {
test = maybe_intern->Pointer;
if (HeapValidate( heap, 0, ((HGLOBAL *)test)-1 ) &&
/* obj(-handle) valid arena? */
HeapValidate( heap, 0, maybe_intern )) /* intern valid arena? */
return handle; /* valid moveable block */
/* note that if pmem is a pointer to a a block allocated by */
/* GlobalAlloc with GMEM_MOVEABLE then magic test in HeapValidate */
/* will fail. */
if (ISPOINTER(pmem)) {
heap = GLOBAL_GetHeap( (HGLOBAL)pmem );
if (HeapValidate( heap, 0, pmem )) {
handle = (HGLOBAL)pmem; /* valid fixed block */
break;
}
handle = POINTER_TO_HANDLE(pmem);
} else
handle = (HGLOBAL)pmem;
/* Now test handle either passed in or retrieved from pointer */
heap = GLOBAL_GetHeap( handle );
maybe_intern = HANDLE_TO_INTERN( handle );
if (maybe_intern->Magic == MAGIC_GLOBAL_USED) {
test = maybe_intern->Pointer;
if (HeapValidate( heap, 0, ((HGLOBAL *)test)-1 ) && /* obj(-handle) valid arena? */
HeapValidate( heap, 0, maybe_intern )) /* intern valid arena? */
break; /* valid moveable block */
}
handle = 0;
SetLastError( ERROR_INVALID_HANDLE );
}
__EXCEPT(page_fault)
{
SetLastError( ERROR_INVALID_HANDLE );
return 0;
}
__ENDTRY
SetLastError( ERROR_INVALID_HANDLE );
return 0;
return handle;
}