xen-kernel -- x86 PV guests may be able to mask interrupts

2016-12-21T00:00:00
ID 3AE078CA-C7EB-11E6-AE1B-002590263BF5
Type freebsd
Reporter FreeBSD
Modified 2016-12-21T00:00:00

Description

The Xen Project reports:

Certain PV guest kernel operations (page table writes in particular) need emulation, and use Xen's general x86 instruction emulator. This allows a malicious guest kernel which asynchronously modifies its instruction stream to effect the clearing of EFLAGS.IF from the state used to return to guest context. A malicious guest kernel administrator can cause a host hang or crash, resulting in a Denial of Service.