CVE-2009-3624

The get_instantiation_keyring function in security/keys/keyctl.c in the
KEYS subsystem in the Linux kernel before 2.6.32-rc5 does not properly
maintain the reference count of a keyring, which allows local users to gain
privileges or cause a denial of service (OOPS) via vectors involving calls
to this function without specifying a keyring by ID, as demonstrated by a
series of keyctl request2 and keyctl list commands.