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.
https://xenbits.xenproject.org/xsa/advisory-397.txt
http://xenbits.xen.org/xsa/advisory-397.html
http://www.openwall.com/lists/oss-security/2022/04/05/1
Source: MITRE
Published: 2022-04-05
Updated: 2022-07-29
Type: CWE-772
Base Score: 4
Vector: AV:L/AC:H/Au:N/C:N/I:N/A:C
Impact Score: 6.9
Exploitability Score: 1.9
Severity: MEDIUM
Base Score: 5.6
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H
Impact Score: 4
Exploitability Score: 1.1
Severity: MEDIUM