Linux kernel before 2.6.18, when running on x86_64 systems, does not
properly save or restore EFLAGS during a context switch, which allows local
users to cause a denial of service (crash) by causing SYSENTER to set an NT
flag, which can trigger a crash on the IRET of the next task.
Updated: 2012-06-01 15:17:28 UTC (commit 5347)