smb: client: fix refcount leak in smb2_set_path_attr

Fix refcount leak in `smb2_set_path_attr` when path conversion fails.

Function `cifs_get_writable_path` returns `cfile` with its reference
counter `cfile->count` increased on success. Function `smb2_compound_op`
would decrease the reference counter for `cfile`, as stated in its
comment. By calling `smb2_rename_path`, the reference counter of `cfile`
would leak if `cifs_convert_path_to_utf16` fails in `smb2_set_path_attr`.

Fixes: 8de9e86 ("cifs: create a helper to find a writeable handle by path name")
Acked-by: Henrique Carvalho <[email protected]>
Signed-off-by: Shuhao Fu <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: sfu2

fs/smb/client/smb2inode.c

@@ -1294,6 +1294,8 @@ static int smb2_set_path_attr(const unsigned int xid, struct cifs_tcon *tcon,
 	smb2_to_name = cifs_convert_path_to_utf16(to_name, cifs_sb);
 	if (smb2_to_name == NULL) {
 		rc = -ENOMEM;
+		if (cfile)
+			cifsFileInfo_put(cfile);
 		goto smb2_rename_path;
 	}
 	in_iov.iov_base = smb2_to_name;