CVE-2022-4139: High severity Linux Linux kernel vulnerability

Incorrect GPU TLB flush code has been discovered in i915 kernel driver. In some cases (Gen12 hardware with specific types of engine) the engine's TLB is not flushed at all. Depending on whether the GPU is running behind an active IOMMU there are two possible scenarios which can happen, due to stale TLB mapping:

1. Without IOMMU - GPU can still access physical memory which could be already assigned by OS to different process. 2. With IOMMU - GPU can access any memory, if the malicious process is able to create/reuse necessary IOMMU mappings.

It is currently not known if specific memory could be targeted, but random memory corruption or data leaks are a known possibility. All Intel integrated and discrete GPUs Gen12 are affected, including Tiger Lake, Rocket Lake, Alder Lake, DG1, Raptor Lake, DG2, Arctic Sound, Meteor Lake.

This vulnerability has similar impact as CVE-2022-0330: https://access.redhat.com/security/cve/CVE-2022-0330.

Reference: https://www.openwall.com/lists/oss-security/2022/11/30/1

— Red Hat

Linux Kernel is vulnerable to a denial of service, caused by an incorrect GPU TLB flush code flaw in the i915 kernel driver. By sending a specially-crafted request, a local attacker could exploit this vulnerability to cause a random memory corruption or data leaks.

— IBM