Re: PATCH: GlobalAddAtomA check for invalid ptr

[Marcus Meissner]

On Thu, Aug 11, 2005 at 02:52:52PM +0200, Alexandre Julliard wrote:
> Marcus Meissner <[EMAIL PROTECTED]> writes:
> 
> > So ... now we can:
> >
> > - fix this program by contacting the developers etc... which is difficult.
> > - fix WINE by adding a check.
> >
> > I can only fix WINE.
> 
> Yes, but please don't use the IsBad* functions, use a proper exception
> handler.

Next try, is this what you imagined.

I now do a strlen() in GlobalAddAtomA(), however the compiler might optimize it
away in the future (gcc 4.1 doesn't).

Ciao, Marcus

Changelog:
        Catch invalid strings in GlobalAddAtomA() using an
        exception handler.

Index: dlls/kernel/atom.c
===================================================================
RCS file: /home/wine/wine/dlls/kernel/atom.c,v
retrieving revision 1.8
diff -u -r1.8 atom.c
--- dlls/kernel/atom.c  10 May 2005 15:15:50 -0000      1.8
+++ dlls/kernel/atom.c  14 Aug 2005 10:24:46 -0000
@@ -38,6 +38,8 @@
 #include "winbase.h"
 #include "winerror.h"
 
+#include "wine/exception.h"
+#include "excpt.h"
 #include "wine/server.h"
 #include "wine/unicode.h"
 #include "kernel_private.h"
@@ -48,6 +50,14 @@
 
 #define MAX_ATOM_LEN 255
 
+/* filter for page-fault exceptions */
+static WINE_EXCEPTION_FILTER(page_fault)
+{
+    if (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION)
+        return EXCEPTION_EXECUTE_HANDLER;
+    return EXCEPTION_CONTINUE_SEARCH;
+}
+
 static struct atom_table* get_local_table(DWORD entries)
 {
     static struct atom_table*   local_table;
@@ -183,6 +193,20 @@
  */
 ATOM WINAPI GlobalAddAtomA( LPCSTR str /* [in] String to add */ )
 {
+    if (HIWORD(str)) {
+       __TRY {
+               char *s = (char*)str;
+               while (*s) s++;
+               /* FIXME: Should make sure the compiler does
+                * not throw away the above.
+                */
+       }
+       __EXCEPT(page_fault) {
+           SetLastError( ERROR_INVALID_PARAMETER );
+           return 0;
+       }
+       __ENDTRY
+    }
     return ATOM_AddAtomA( str, NULL );
 }