The Linux kernel 2.6.x up to 2.6.18, and possibly other versions, on Fedora Core 6 and possibly other operating systems, allows local users to cause a denial of service (crash) via a malformed gfs2 file stream that triggers a NULL pointer dereference in the init_journal function.
https://exchange.xforce.ibmcloud.com/vulnerabilities/30307
http://www.vupen.com/english/advisories/2006/4556
http://www.ubuntu.com/usn/usn-416-1