Bug 1890653 (CVE-2020-27661)

Summary:	CVE-2020-27661 QEMU: divide by zero in dwc2_handle_packet() in hw/usb/hcd-dwc2.c
Product:	[Other] Security Response	Reporter:	Mauro Matteo Cascella <mcascell>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	ailan, amit, berrange, cfergeau, dbecker, drjones, dwmw2, imammedo, itamar, jen, jferlan, jforbes, jjoyce, jmaloy, jschluet, knoel, lhh, lkundrak, lpeer, m.a.young, mburns, mkenneth, mrezanin, mst, pbonzini, ribarry, rjones, robinlee.sysu, sclewis, slinaber, virt-maint, virt-maint, vkuznets, xen-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A divide-by-zero flaw was found in QEMU in the dwc-hsotg (dwc2) USB host controller emulation. More specifically, HCCHAR_MPS was read from a device register and later used as a divisor without performing a sanity check. This flaw allows a malicious or buggy guest to crash the QEMU process on the host, resulting in a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-10-22 20:21:26 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1890654, 1910669
Bug Blocks:	1882704

Description Mauro Matteo Cascella 2020-10-22 16:35:57 UTC

A divide-by-zero issue was found in QEMU in the dwc-hsotg (dwc2) USB host controller emulation. More specifically, HCCHAR_MPS was read from a device register and later used as divisor without performing any sanity check. This could allow a malicious/buggy guest to crash the QEMU process on the host, resulting in a denial of service.

Upstream fix:
https://lists.nongnu.org/archive/html/qemu-devel/2020-10/msg04263.html

Comment 1 Mauro Matteo Cascella 2020-10-22 16:36:30 UTC

Created qemu tracking bugs for this issue:

Affects: fedora-all [bug 1890654]

Comment 2 Mauro Matteo Cascella 2020-10-22 16:52:35 UTC

Statement:

This flaw did not affect the following versions of QEMU as they did not include support for dwc2 USB host controller emulation:
* `qemu-kvm-ma` as shipped with Red Hat Enterprise Linux 7.
* `qemu-kvm-rhev` as shipped with Red Hat Virtualization and Red Hat OpenStack.
* `qemu-kvm` as shipped with Red Hat Enterprise Linux 6, 7, 8, and RHEL Advanced Virtualization.

Comment 3 Product Security DevOps Team 2020-10-22 20:21:26 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-27661

Comment 5 Mauro Matteo Cascella 2020-10-23 12:53:18 UTC

Acknowledgments:

Name: Gaoning Pan (Ant Security Light-Year Lab), Xingwei Lin (Ant Security Light-Year Lab)