Launchpad.net

CVE 2011-1021

drivers/acpi/debugfs.c in the Linux kernel before 3.0 allows local users to modify arbitrary kernel memory locations by leveraging root privileges to write to the /sys/kernel/debug/acpi/custom_method file. NOTE: this vulnerability exists because of an incomplete fix for CVE-2010-4347.

See the CVE page on Mitre.org for more details.