Bug 1827808 (CVE-2020-10717)

Summary:	CVE-2020-10717 QEMU: virtiofsd: guest may open maximum file descriptor to cause DoS
Product:	[Other] Security Response	Reporter:	Prasad Pandit <ppandit>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	amit, berrange, cfergeau, dgilbert, dwmw2, itamar, jen, jferlan, jjoyce, jmaloy, jschluet, knoel, lhh, lpeer, mburns, mkenneth, mrezanin, mst, pbonzini, ribarry, rjones, sclewis, security-response-team, slinaber, virt-maint, virt-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	QEMU-5.0.1	Doc Type:	If docs needed, set a value
Doc Text:	A potential DoS flaw was found in the virtio-fs shared file system daemon (virtiofsd) implementation of the QEMU version >= v5.0. Virtio-fs is meant to share a host file system directory with a guest via virtio-fs device. If the guest opens the maximum number of file descriptors under the shared directory, a denial of service may occur. This flaw allows a guest user/process to cause this denial of service on the host.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-12-15 11:31:52 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:	1817445, 1830842, 1830844, 1830845
Bug Blocks:	1825755

Description Prasad Pandit 2020-04-24 20:42:59 UTC

A potential DoS issue was found in the virtio-fs shared file system daemon (virtiofsd) implementation of the QEMU. Virtiofsd is meant to share a host file system directory with a guest via virtio-fs device. The said DoS may occur on the host, if the guest was to open the maximum number of file descriptors under the shared directory. A guest user/process may use this flaw to cause DoS issue on the host.

Upstream patch(es):
-------------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg00143.html
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg00141.html

Reference:
----------
  -> https://www.openwall.com/lists/oss-security/2020/05/04/1

Comment 1 Prasad Pandit 2020-04-24 20:43:05 UTC

Acknowledgments:

Name: Yuval Avrahami (Palo Alto Networks)

Comment 3 Prasad Pandit 2020-05-04 05:51:21 UTC

Created qemu tracking bugs for this issue:

Affects: fedora-rawhide [bug 1830842]