[PATCH 2/2] kernelbase: Limit the maximum path length for filesystem.

[yaoyongjie]

From: yaoyongjie

In CopyFileEx, and DeleteFile functions, by default, the file name
and path are limited to MAX_PATH characters. To extend this limit
to 32,767 wide characters, need prepend "\\?\" to the path.

If alloc is FALSE, file_name_AtoW will uses the TEB static buffer,
but the buffer size is only MAX_PATH charactors. If DeleteFileA
is to support long paths prefixed with "\\?\", alloc must be set to TRUE.
---
 dlls/kernelbase/file.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/dlls/kernelbase/file.c b/dlls/kernelbase/file.c
index f0dedfe3b14..1b254187601 100644
--- a/dlls/kernelbase/file.c
+++ b/dlls/kernelbase/file.c
@@ -512,6 +512,18 @@ static BOOL copy_file( const WCHAR *source, const WCHAR *dest, COPYFILE2_EXTENDE
         SetLastError( ERROR_INVALID_PARAMETER );
         return FALSE;
     }
+
+    if (wcsncmp(dest, L"\\?\", 4) && wcslen(dest) >= MAX_PATH )
+    {
+        SetLastError( ERROR_PATH_NOT_FOUND );
+        return FALSE;
+    }
+    if (wcsncmp(dest, L"\\?\", 4) && wcslen(dest) >= MAX_PATH )
+    {
+        SetLastError( ERROR_PATH_NOT_FOUND );
+        return FALSE;
+    }
+
     if (!(buffer = HeapAlloc( GetProcessHeap(), 0, buffer_size )))
     {
         SetLastError( ERROR_NOT_ENOUGH_MEMORY );
@@ -991,9 +1003,12 @@ BOOLEAN WINAPI /* DECLSPEC_HOTPATCH */ CreateSymbolicLinkW( LPCWSTR link, LPCWST
 BOOL WINAPI DECLSPEC_HOTPATCH DeleteFileA( LPCSTR path )
 {
     WCHAR *pathW;
+    BOOL res;

-    if (!(pathW = file_name_AtoW( path, FALSE ))) return FALSE;
-    return DeleteFileW( pathW );
+    if (!(pathW = file_name_AtoW( path, TRUE ))) return FALSE;
+    res = DeleteFileW( pathW );
+    HeapFree( GetProcessHeap(), 0, pathW );
+    return res;
 }

@@ -1010,6 +1025,12 @@ BOOL WINAPI DECLSPEC_HOTPATCH DeleteFileW( LPCWSTR path )

TRACE( "%s\n", debugstr_w(path) );

+    if (path && wcsncmp(path, L"\\?\", 4) && wcslen(path) >= MAX_PATH )
+    {
+        SetLastError( ERROR_PATH_NOT_FOUND );
+        return FALSE;
+    }
+
     if (!RtlDosPathNameToNtPathName_U( path, &nameW, NULL, NULL ))
     {
         SetLastError( ERROR_PATH_NOT_FOUND );