CVE Vulnerabilities

CVE-2022-26356

Improper Locking

Published: Apr 05, 2022 | Modified: Feb 04, 2024
CVSS 3.x
5.6
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H
CVSS 2.x
4 MEDIUM
AV:L/AC:H/Au:N/C:N/I:N/A:C
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

Racy interactions between dirty vram tracking and paging log dirty hypercalls Activation of log dirty mode done by XEN_DMOP_track_dirty_vram (was named HVMOP_track_dirty_vram before Xen 4.9) is racy with ongoing log dirty hypercalls. A suitably timed call to XEN_DMOP_track_dirty_vram can enable log dirty while another CPU is still in the process of tearing down the structures related to a previously enabled log dirty mode (XEN_DOMCTL_SHADOW_OP_OFF). This is due to lack of mutually exclusive locking between both operations and can lead to entries being added in already freed slots, resulting in a memory leak.

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Name Vendor Start Version End Version
Xen Xen 4.0.0 (including) 4.12.0 (excluding)
Xen Xen 4.13.0 (including) 4.14.0 (excluding)
Xen Xen 4.15.0 (including) 4.16.0 (excluding)
Xen Ubuntu bionic *
Xen Ubuntu impish *
Xen Ubuntu kinetic *
Xen Ubuntu lunar *
Xen Ubuntu trusty *
Xen Ubuntu xenial *

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

References