Bug 1759820 (CVE-2019-12067)

Summary:	CVE-2019-12067 QEMU: NULL dereference in ahci_commit_buf() leading to DoS
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	ailan, amit, areis, berrange, cfergeau, drjones, dwmw2, imammedo, itamar, jen, jferlan, jforbes, jjoyce, jschluet, knoel, lhh, lpeer, m.a.young, mburns, mkenneth, mrezanin, mst, pbonzini, ppandit, rbalakri, ribarry, rjones, rkrcmar, 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:	Bug Fix
Doc Text:	A NULL pointer dereference flaw was found in the QEMU emulator's IDE AHCI emulator. Exploitation of the flaw could occur while committing DMA buffer in ahci_commit_buf() if the command header 'ad->cur_cmd' was null. A privileged guest user could use this flaw to crash the QEMU process instance resulting in DoS. Reduced performance of the system is the highest threat to the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-25 09:52:47 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:	1759910, 1759911, 1779881, 1779882, 1782763, 1782765, 1782789, 1793218
Bug Blocks:	1710974, 1759821

Description Marian Rehak 2019-10-09 08:20:27 UTC

QEMU emulator built with the AHCI emulator support is vulnerable to a NULL pointer dereference issue. It could occur while committing DMA buffer in ahci_commit_buf() if the command header 'ad->cur_cmd' is null.

A privileged guest user could use this flaw to crash the QEMU process instance resulting in DoS.

Upstream Patch:
  -> https://lists.gnu.org/archive/html/qemu-devel/2019-08/msg01358.html

Comment 1 Marian Rehak 2019-10-09 11:58:08 UTC

Created qemu tracking bugs for this issue:

Affects: fedora-all [bug 1759911]


Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1759910]

Comment 8 Eric Christensen 2019-12-16 16:24:32 UTC

Statement:

The qemu-kvm package versions as shipped with Red Hat Enterprise Linux 6 and 7 are not affected by this issue. 

The qemu-kvm package version as shipped with Red Hat Enterprise Linux 8 is affected by this issue. Future qemu-kvm updates for Red Hat Enterprise Linux 8 may address this issue.