Debian 8 Jessie DLA-1990-1: Critical Update for Linux Kernel 4.9

It was discovered that on Intel CPUs supporting hardware
virtualisation with Extended Page Tables (EPT), a guest VM may
manipulate the memory management hardware to cause a Machine Check
Error (MCE) and denial of service (hang or crash).

The guest triggers this error by changing page tables without a
TLB flush, so that both 4 KB and 2 MB entries for the same virtual
address are loaded into the instruction TLB (iTLB). This update
implements a mitigation in KVM that prevents guest VMs from
loading 2 MB entries into the iTLB. This will reduce performance
of guest VMs.

Further information on the mitigation can be found at

or in the linux-doc-4.9 package.

Intel's explanation of the issue can be found at
;.

CVE-2019-0154

Intel discovered that on their 8th and 9th generation GPUs,
reading certain registers while the GPU is in a low-power state
can cause a system hang. A local user permitted to use the GPU