The gfs2_lock function in the Linux kernel before 2.6.34-rc1-next-20100312, and the gfs_lock function in the Linux kernel on Red Hat Enterprise Linux (RHEL) 5 and 6, does not properly remove POSIX locks on files that are setgid without group-execute permission, which allows local users to cause a denial of service (BUG and system crash) by locking a file on a (1) GFS or (2) GFS2 filesystem, and then changing this file's permissions.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11392
http://www.redhat.com/support/errata/RHSA-2010-0521.html
http://www.redhat.com/support/errata/RHSA-2010-0380.html
http://www.redhat.com/support/errata/RHSA-2010-0330.html
http://www.mandriva.com/security/advisories?name=MDVSA-2010:066
http://www.kernel.org/pub/linux/kernel/v2.6/next/patch-v2.6.34-rc1-next-20100312.bz2
http://www.debian.org/security/2010/dsa-2053
http://securitytracker.com/id?1023809