Bug 1773749 (CVE-2019-12068)

Summary:	CVE-2019-12068 qemu: scsi: lsi: potential infinite loop when executing script in lsi_execute_script
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
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, areis, bdettelb, berrange, cfergeau, dbecker, drjones, dwmw2, imammedo, itamar, jen, jferlan, jforbes, jjoyce, jschluet, jschorr, kbasil, knoel, lhh, lkundrak, lpeer, m.a.young, mburns, mkenneth, mrezanin, mst, pbonzini, ppandit, rbalakri, 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 flaw was found in QEMU's LSI53C895A device emulator. When executing LSI scripts, a crafted sequence of I/O requests may cause the emulator to enter into an infinite loop. This vulnerability could be executed locally and would affect the availability of the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-12-06 14:34:40 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:	1773750, 1773751, 1780346, 1780347, 1780348, 1780349, 1781422, 1782735
Bug Blocks:	1710974, 1773752

Description Guilherme de Almeida Suckevicz 2019-11-18 20:46:26 UTC

Qemu emulator built with the LSI53C895A SCSI Host Bus Adapter emulation support
is vulnerable to an infinite loop issue. It could occur when executing a script
in lsi_execute_script(). The LSI scsi adapter emulator advances 's->dsp' index
to read next opcode. This can lead to an infinite loop if the next opcode is
empty.

A privileged user inside guest could use this flaw to consume CPU cycles on
the host resulting in DoS scenario.

Upstream patch:
---------------
  -> https://git.qemu.org/?p=qemu.git;a=commit;h=de594e47659029316bbf9391efb79da0a1a08e08

Comment 1 Guilherme de Almeida Suckevicz 2019-11-18 20:46:50 UTC

Created qemu tracking bugs for this issue:

Affects: epel-7 [bug 1773751]
Affects: fedora-all [bug 1773750]

Comment 3 Paolo Bonzini 2019-12-06 14:34:40 UTC

The device is not included in RHEL.

Comment 7 Eric Christensen 2019-12-09 21:03:32 UTC

Statement:

The qemu-kvm package versions as shipped with Red Hat Enterprise Linux 6, 7, and 8 are not affected by this issue, as the device, LSI53C895A, is not included in these versions.

Comment 9 Prasad Pandit 2019-12-12 08:52:49 UTC

Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1782735]