libceph: prevent potential out-of-bounds reads in handle_auth_done()

libceph: prevent potential out-of-bounds reads in handle_auth_done()

commit 818156caffbf55cb4d368f9c3cac64e458fb49c9 upstream.

Perform an explicit bounds check on payload_len to avoid a possible
out-of-bounds access in the callout.

[ idryomov: changelog ]

Cc: stable@vger.kernel.org
Signed-off-by: ziming zhang <ezrakiez@gmail.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>