The dbg_lvl file for the megaraid_sas driver in the Linux kernel before 2.6.27 has world-writable permissions, which allows local users to change the (1) behavior and (2) logging level of the driver by modifying this file.
Exploitability
AV:LAC:LAu:NImpact
C:NI:CA:C6.6/AV:L/AC:L/Au:N/C:N/I:C/A:C