Bug 1230770 (CVE-2015-4692)

Summary:	CVE-2015-4692 kernel: kvm x86: NULL pointer dereference in kvm_apic_has_events function
Product:	[Other] Security Response	Reporter:	Vasyl Kaigorodov <vkaigoro>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	aquini, bhu, carnil, dhoward, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, joelsmith, jonathan, jross, jrusnack, jwboyer, kernel-maint, kernel-mgr, lgoncalv, madhu.chinakonda, matt, mchehab, mcressma, mrg-program-list, nmurray, plougher, pmatouse, ppandit, rvrbovsk, slong, vvs, williams, wmealing
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A DoS flaw was found for a Linux kernel built for the x86 architecture which had the KVM virtualization support(CONFIG_KVM) enabled. The kernel would be vulnerable to a NULL pointer dereference flaw in Linux kernel's kvm_apic_has_events() function while doing an ioctl. An unprivileged user able to access the "/dev/kvm" device could use this flaw to crash the system kernel.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 02:41:53 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:	1230774
Bug Blocks:	1230771

Description Vasyl Kaigorodov 2015-06-11 14:04:03 UTC

Linux kernel built for the x86 architecture, with the KVM virtualisation support(CONFIG_KVM) is vulnerable to a NULL pointer dereference flaw. It could occur while doing KVM's Virtual CPU ioctl(2) call, in Linux kernel's kvm_apic_has_events() function.

An unprivileged user able to access "/dev/kvm" device, could use this flaw to crash the system kernel resulting in DoS.

Upstream fix:
-------------
  -> https://lkml.org/lkml/2015/6/4/163

Reference:
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  -> http://seclists.org/oss-sec/2015/q2/680

Comment 1 Vasyl Kaigorodov 2015-06-11 14:08:41 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1230774]

Comment 2 Prasad Pandit 2015-06-18 11:12:24 UTC

Statement:

This issue does not affect the versions of Linux kernel as shipped with
Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2.

This issue affects the version of the kernel package as shipped with
Red Hat Enterprise Linux 7.

Comment 3 Prasad Pandit 2015-06-18 11:13:59 UTC

This has been rated as having Moderate security impact and is not currently
planned to be addressed in future updates. For additional information, refer
to the Red Hat Enterprise Linux Life Cycle:

 -> https://access.redhat.com/support/policy/updates/errata/

Comment 5 Fedora Update System 2015-06-27 12:39:42 UTC

kernel-4.0.6-300.fc22 has been pushed to the Fedora 22 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2015-06-30 20:12:47 UTC

kernel-4.0.6-200.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 7 Vasily Averin 2016-02-03 09:43:54 UTC

Please update description, seems it was fixed in RHEL7.2
https://access.redhat.com/labs/psb/versions/kernel-3.10.0-327.el7/patches/kvm-x86-fix-kvm_apic_has_events-to-check-for-NULL-pointer