The pkt_ioctl function in the pktcdvd block device ioctl handler (pktcdvd.c) in Linux kernel 2.6.12-rc4 and earlier calls the wrong function before passing an ioctl to the block device, which crosses security boundaries by making kernel address space accessible from user space and allows local users to cause a denial of service and possibly execute arbitrary code, a similar vulnerability to CVE-2005-1264.