Bug 2243164 (CVE-2023-34324)

Summary:	CVE-2023-34324 xen: possible deadlock in Linux kernel event handling
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	jforbes
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:	2243165
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Description Marian Rehak 2023-10-11 04:48:59 UTC

Closing of an event channel in the Linux kernel can result in a deadlock. This happens when the close is being performed in parallel to an unrelated Xen console action and the handling of a Xen console interrupt in an unprivileged guest. The closing of an event channel is e.g. triggered by removal of a paravirtual device on the other side. As this action will cause console messages to be issued on the other side quite often, the chance of triggering the deadlock is not neglectable.
A (malicious) guest administrator could cause a denial of service (DoS) in a backend domain (other than dom0) by disabling a paravirtualized device. A malicious backend could cause DoS in a guest running a Linux kernel by disabling a paravirtualized device.

Comment 1 Marian Rehak 2023-10-11 04:49:12 UTC

Created xen tracking bugs for this issue:

Affects: fedora-all [bug 2243165]

Comment 2 Justin M. Forbes 2023-10-12 16:49:25 UTC

This is fixed in the 6.5.7 stable kernel updates.