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.
History

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cve-icon MITRE Information

Status: PUBLISHED

Assigner: mitre

Published: 2020-12-15T16:50:37

Updated: 2021-07-12T04:06:23

Reserved: 2020-12-04T00:00:00


Link: CVE-2020-29567

JSON object: View

cve-icon NVD Information

Status : Modified

Published: 2020-12-15T17:15:14.597

Modified: 2023-11-07T03:21:31.870


Link: CVE-2020-29567

JSON object: View

cve-icon Redhat Information

No data.

CWE