fix(safeio): retain writable Windows parent handles

2026-08-18 09:05:42 +02:00
parent e7a7f4f066
commit 74b062f1a7
3 changed files with 41 additions and 25 deletions
@@ -16,15 +16,17 @@ func preflightPrivateDirectory(path string) (bool, error) {
 	handle, err := openWindowsRelativeComponent(parents.handles[len(parents.handles)-1], target, true, windows.GENERIC_READ)
 	if err != nil {
 		if isWindowsRelativeNotFound(err) {
-			writableParent, accessErr := openWindowsComponentWithAccess(
-				parents.directory,
-				true,
+			// A read-only retained handle cannot be upgraded. Re-traverse with the
+			// directory FILE_ADD_SUBDIRECTORY right, still using RootDirectory-relative
+			// opens for every component rather than reopening parents by absolute path.
+			writableParents, _, accessErr := openCanonicalWindowsParentWithFinalAccess(
+				path,
 				windows.FILE_APPEND_DATA, // FILE_ADD_SUBDIRECTORY for a directory handle
 			)
-			if accessErr != nil {
+			if accessErr != nil || writableParents == nil {
 				return false, ErrUnsafeFile
 			}
-			_ = windows.CloseHandle(writableParent)
+			writableParents.Close()
 			return false, nil
 		}
 		return false, ErrUnsafeFile