OracleVM 3.3 : xen (OVMSA-2017-0008)
High Nessus Plugin ID 96521
SynopsisThe remote OracleVM host is missing one or more security updates.
DescriptionThe remote OracleVM system is missing necessary patches to address critical security updates :
- From: Andrew Cooper Date: Sun, 18 Dec 2016 15:42:59 +0000 Subject: [PATCH] x86/emul: Correct the handling of eflags with SYSCALL A singlestep #DB is determined by the resulting eflags value from the execution of SYSCALL, not the original eflags value. By using the original eflags value, we negate the guest kernels attempt to protect itself from a privilege escalation by masking TF. Introduce a tf boolean and have the SYSCALL emulation recalculate it after the instruction is complete. This is XSA-204
- From: Jan Beulich Subject: x86: force EFLAGS.IF on when exiting to PV guests Guest kernels modifying instructions in the process of being emulated for another of their vCPU-s may effect EFLAGS.IF to be cleared upon next exiting to guest context, by converting the being emulated instruction to CLI (at the right point in time). Prevent any such bad effects by always forcing EFLAGS.IF on. And to cover hypothetical other similar issues, also force EFLAGS.[IOPL,NT,VM] to zero. This is XSA-202.
SolutionUpdate the affected xen / xen-tools packages.