An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.
Metrics
Affected Vendors & Products
References
History
No history.
MITRE
Status: PUBLISHED
Assigner: mitre
Published: 2020-09-23T21:14:03
Updated: 2024-08-04T15:33:05.776Z
Reserved: 2020-09-16T00:00:00
Link: CVE-2020-25601
Vulnrichment
No data.
NVD
Status : Modified
Published: 2020-09-23T22:15:13.713
Modified: 2024-11-21T05:18:12.487
Link: CVE-2020-25601
Redhat