access_mask needed for rename

[Kenny Dinh]

Hi all,

In the *can_rename* function in *source3/smbd/reply.c*, we check for of an
existing open handle's access_mask to have either DELETE_ACCESS or
FILE_WRITE_ATTRIBUTES to decide if the rename operation is allowed.  This
means that if the file was opened with only FILE_WRITE_ATTRIBUTES without
DELETE_ACCESS, the rename would be allowed to go through.  This failed the
smbtorture *smb2.rename.simple_no_delete *test.
The strict rule (which is what MS does) is to allow rename request to go
through only if DELETE_ACCESS is specified.

Was there any reason to relax to rule, (and deviate from the behavior on MS
server), to allow the rename to go through even when the file handle was
opened with only the FILE_WRITE_ATTRIBUTES access_mask?

Below is the function, and the line in question is 2685.

2654 static NTSTATUS can_rename(connection_struct *conn, files_struct *fsp,
2655                         uint16_t dirtype)
2656 {
2657         if (!CAN_WRITE(conn)) {
2658                 return NT_STATUS_MEDIA_WRITE_PROTECTED;
2659         }
2660
2661         if ((dirtype & (FILE_ATTRIBUTE_HIDDEN |
FILE_ATTRIBUTE_SYSTEM)) !=
2662                         (FILE_ATTRIBUTE_HIDDEN |
FILE_ATTRIBUTE_SYSTEM)) {
2663                 /* Only bother to read the DOS attribute if we might
deny the
2664                    rename on the grounds of attribute missmatch. */
2665                 uint32_t fmode = dos_mode(conn, fsp->fsp_name);
2666                 if ((fmode & ~dirtype) & (FILE_ATTRIBUTE_HIDDEN |
FILE_ATTRIBUTE_SYSTEM)) {
2667                         return NT_STATUS_NO_SUCH_FILE;
2668                 }
2669         }
2670
2671         if (S_ISDIR(fsp->fsp_name->st.st_ex_mode)) {
2672                 if (fsp->posix_flags &
(FSP_POSIX_FLAGS_OPEN|FSP_POSIX_FLAGS_RENAME)) {
2673                         return NT_STATUS_OK;
2674                 }
2675
2676                 /* If no pathnames are open below this
2677                    directory, allow the rename. */
2678
2679                 if (file_find_subpath(fsp)) {
2680                         return NT_STATUS_ACCESS_DENIED;
2681                 }
2682                 return NT_STATUS_OK;
2683         }
2684
*2685         if (fsp->access_mask & (DELETE_ACCESS|FILE_WRITE_ATTRIBUTES))
{*
*2686                 return NT_STATUS_OK;*
*2687         }*
2688
2689         return NT_STATUS_ACCESS_DENIED;
2690 }