The cifs_create function in fs/cifs/dir.c in the Linux kernel 2.6.33.2 and earlier allows local users to cause a denial of service (NULL pointer dereference and OOPS) or possibly have unspecified other impact via a NULL nameidata (aka nd) field in a POSIX file-creation request to a server that supports UNIX extensions.
https://exchange.xforce.ibmcloud.com/vulnerabilities/57561
https://bugzilla.redhat.com/show_bug.cgi?id=579445
http://www.securityfocus.com/bid/39186
http://openwall.com/lists/oss-security/2010/04/06/2
http://marc.info/?l=oss-security&m=127045779122119&w=2
http://marc.info/?l=oss-security&m=127045754521927&w=2
http://lists.samba.org/archive/linux-cifs-client/2010-April/005757.html
http://lists.samba.org/archive/linux-cifs-client/2010-April/005746.html
http://lists.samba.org/archive/linux-cifs-client/2010-April/005742.html
http://lists.samba.org/archive/linux-cifs-client/2010-April/005741.html