Description of problem:
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.
Proposed upstream patch:
Created attachment 313340 [details]
Upstream patch for this issue
This was addressed via:
Red Hat Enterprise Linux version 5 (RHSA-2008:0957)