Bug 1921313 (CVE-2021-3308)

Summary: CVE-2021-3308 xen: IRQ vector leak on x86
Product: [Other] Security Response Reporter: Pedro Sampaio <psampaio>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED UPSTREAM QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: jforbes, m.a.young, robinlee.sysu
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Last Closed: 2021-01-28 02:41:39 UTC Type: ---
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Bug Depends On: 1921314    
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Description Pedro Sampaio 2021-01-27 21:11:43 UTC 
An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.

http://www.openwall.com/lists/oss-security/2021/01/26/4
http://xenbits.xen.org/xsa/advisory-360.html
Comment 1 Pedro Sampaio 2021-01-27 21:12:09 UTC 
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1921314]
Comment 2 Product Security DevOps Team 2021-01-28 02:41:39 UTC 
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.