samba -- Unexpected code execution in smbd

Samba development team reports:

All versions of Samba from 3.5.0 to 4.2.0rc4 are
vulnerable to an unexpected code execution vulnerability
in the smbd file server daemon.
A malicious client could send packets that may set up the
stack in such a way that the freeing of memory in a
subsequent anonymous netlogon packet could allow execution
of arbitrary code. This code would execute with root
privileges.