ntdll: Catch page fault in RtlWow64EnableFsRedirectionEx.

dlls/ntdll/directory.c

@@ -106,6 +106,7 @@
 #include "wine/list.h"
 #include "wine/library.h"
 #include "wine/debug.h"
+#include "wine/exception.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(file);
 
@@ -2996,9 +2997,17 @@ NTSTATUS WINAPI RtlWow64EnableFsRedirection( BOOLEAN enable )
 NTSTATUS WINAPI RtlWow64EnableFsRedirectionEx( ULONG disable, ULONG *old_value )
 {
     if (!is_wow64) return STATUS_NOT_IMPLEMENTED;
-    if (((ULONG_PTR)old_value >> 16) == 0) return STATUS_ACCESS_VIOLATION;
 
-    *old_value = !ntdll_get_thread_data()->wow64_redir;
+    __TRY
+    {
+        *old_value = !ntdll_get_thread_data()->wow64_redir;
+    }
+    __EXCEPT_PAGE_FAULT
+    {
+        return STATUS_ACCESS_VIOLATION;
+    }
+    __ENDTRY
+
     ntdll_get_thread_data()->wow64_redir = !disable;
     return STATUS_SUCCESS;
 }

dlls/ntdll/tests/directory.c

@@ -861,6 +861,8 @@ static void test_redirection(void)
     ok( status == STATUS_ACCESS_VIOLATION, "RtlWow64EnableFsRedirectionEx failed with status %x\n", status );
     status = pRtlWow64EnableFsRedirectionEx( TRUE, (void*)1 );
     ok( status == STATUS_ACCESS_VIOLATION, "RtlWow64EnableFsRedirectionEx failed with status %x\n", status );
+    status = pRtlWow64EnableFsRedirectionEx( TRUE, (void*)0xDEADBEEF );
+    ok( status == STATUS_ACCESS_VIOLATION, "RtlWow64EnableFsRedirectionEx failed with status %x\n", status );
 
     status = pRtlWow64EnableFsRedirection( FALSE );
     ok( !status, "RtlWow64EnableFsRedirectionEx failed status %x\n", status );