Description of problem:
From me, while creating a file on a server which supports unix extensions such as Samba, if a file is being created which does not supply nameidata (i.e. nd is null), cifs client can oops when calling cifs_posix_open.
[linux-cifs-client[[patch] Attempt #2 to handle null nameidata
Not vulnerable. This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 3, 4, 5 and Red Hat Enterprise MRG as they did not include support for posix opens on lookup.