win32_apply.c: set_short_name(): Increase minimum buffer size

diff --git a/src/win32_apply.c b/src/win32_apply.c
index 1f68b69f18d732c2dc4c894a81cad2d2b9fa46f5..a6b37c4a90cda4375a874fa7d9691ad63a80b82b 100644 (file)
--- a/src/win32_apply.c
+++ b/src/win32_apply.c
@@ -851,8 +851,20 @@ set_short_name(HANDLE h, const struct wim_dentry *dentry,
        if (!ctx->common.supported_features.short_names)
                return 0;
 
+       /*
+        * Note: The size of the FILE_NAME_INFORMATION buffer must be such that
+        * FileName contains at least 2 wide characters (4 bytes).  Otherwise,
+        * NtSetInformationFile() will return STATUS_INFO_LENGTH_MISMATCH.  This
+        * is despite the fact that FileNameLength can validly be 0 or 2 bytes,
+        * with the former case being removing the existing short name if
+        * present, rather than setting one.
+        *
+        * FileName seemingly does not, however, need to be null-terminated in
+        * any case.
+        */
+
        size_t bufsize = offsetof(FILE_NAME_INFORMATION, FileName) +
-                        dentry->short_name_nbytes;
+                        max(dentry->short_name_nbytes, 2 * sizeof(wchar_t));
        u8 buf[bufsize] _aligned_attribute(8);
        FILE_NAME_INFORMATION *info = (FILE_NAME_INFORMATION *)buf;
        NTSTATUS status;