CVEvulnerability

CVE-2020-29567

6.2 MEDIUM Published 2020-12-15 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-12-15
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
6.2 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 ([email protected])
4.9 MEDIUM — AV:L/AC:L/Au:N/C:N/I:N/A:C
Weaknesses
CWE-770

Description

An issue was discovered in Xen 4.14.x. When moving IRQs between CPUs to distribute the load of IRQ handling, IRQ vectors are dynamically allocated and de-allocated on the relevant CPUs. De-allocation has to happen when certain constraints are met. If these conditions are not met when first checked, the checking CPU may send an interrupt to itself, in the expectation that this IRQ will be delivered only after the condition preventing the cleanup has cleared. For two specific IRQ vectors, this expectation was violated, resulting in a continuous stream of self-interrupts, which renders the CPU effectively unusable. A domain with a passed through PCI device can cause lockup of a physical CPU, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only guests with physical PCI devices passed through to them can exploit the vulnerability.

Affected configurations

• xen xen (<= 4.14.0) • fedoraproject fedora 33

Related

Weakness · CWE (1)

  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References