Bug 1924042 (CVE-2021-3392)

Summary:	CVE-2021-3392 QEMU: scsi: mptsas: use-after-free while processing io requests
Product:	[Other] Security Response	Reporter:	Prasad Pandit <ppandit>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	acaringi, ailan, berrange, bhu, bmasney, brdeoliv, cfergeau, dbecker, dhoward, drjones, dvlasenk, fhrbata, hkrzesin, imammedo, itamar, jen, jferlan, jforbes, jjoyce, jmaloy, jschluet, jshortt, jstancek, knoel, lhh, lpeer, m.a.young, mburns, mkenneth, mrezanin, mst, nmurray, ondrejj, pbonzini, philmd, ptalbert, ribarry, rjones, robinlee.sysu, rvrbovsk, sclewis, slinaber, virt-maint, virt-maint, vkuznets, walters, xen-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	qemu 6.0.0	Doc Type:	---
Doc Text:	A use-after-free flaw was found in the MegaRAID emulator of QEMU. This issue occurs while processing SCSI I/O requests in the case of an error mptsas_free_request() that does not dequeue the request object 'req' from a pending requests queue. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-02-02 14:42:25 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:	1924043
Bug Blocks:	1908264, 1939717

Description Prasad Pandit 2021-02-02 13:22:04 UTC

A use-after-free issue was found in the Megaraid emulator of the QEMU. It occurs while processing SCSI i/o requests because in case of an error mptsas_free_request() does not dequeue request object 'req' from a pending requests' queue. Which later gets processed resulting in the said use-after-free issue. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg00488.html

Comment 1 Prasad Pandit 2021-02-02 13:22:14 UTC

Acknowledgments:

Name: Cheolwoo Myung (Seoul National University)

Comment 3 Prasad Pandit 2021-02-02 13:24:47 UTC

Created qemu tracking bugs for this issue:

Affects: fedora-all [bug 1924043]

Comment 4 Product Security DevOps Team 2021-02-02 14:42:25 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-2021-3392

Comment 5 Mauro Matteo Cascella 2021-02-02 16:00:08 UTC

Statement:

This issue does not affect the versions of `qemu-kvm` as shipped with Red Hat products, as they do not include support for the LSI SAS1068 controller emulation.

Comment 6 Mauro Matteo Cascella 2021-04-20 07:29:06 UTC

Upstream fix:
https://git.qemu.org/?p=qemu.git;a=commit;h=3791642c8d60029adf9b00bcb4e34d7d8a1aea4d