Bug 1786078 (CVE-2019-19807)

Summary:	CVE-2019-19807 kernel: use-after-free in sound/core/timer.c
Product:	[Other] Security Response	Reporter:	msiddiqu
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	acaringi, airlied, asavkov, bdettelb, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, joe.lawrence, john.j5live, jonathan, josef, jpoimboe, jross, jschorr, jshortt, jstancek, jthierry, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, qzhao, rhandlin, rt-maint, rvrbovsk, steved, williams, ycote, yozone
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 memory flaw was found in the ALSA subsystem of the Linux kernel. The struct snd_timer_instance function fails the timer->max_instances check leading to an invalid address. This could lead to a use-after-free vulnerability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-07-21 13:27:42 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:	1786080, 1795892, 1795893, 1795894, 1795895, 1798457, 1798459, 1798467, 1798468, 1798469, 1798470, 1798476, 1821714, 1821715, 1888653
Bug Blocks:	1786081

Description msiddiqu 2019-12-23 10:48:50 UTC

In the Linux kernel, sound/core/timer.c has a use-after-free caused by erroneous code refactoring. This is related to snd_timer_open and snd_timer_close_locked. The timeri variable was originally intended to be for a newly created timer instance, but was used for a different purpose after refactoring.

References: 

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.11

Upstream Patch:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e7af6307a8a54f0b873960b32b6a644f2d0fbd97https://github.com/torvalds/linux/commit/e7af6307a8a54f0b873960b32b6a644f2d0fbd97

Comment 1 msiddiqu 2019-12-23 10:49:28 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1786080]

Comment 2 Justin M. Forbes 2019-12-23 15:19:57 UTC

This was fixed for Fedora with the 5.3.11 stable kernel updates.

Comment 5 Rohit Keshri 2020-01-29 07:26:52 UTC

Mitigation:

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Comment 10 Rohit Keshri 2020-04-07 12:54:41 UTC

Statement:

This issue affected Linux kernel versions as shipped with Red Hat Enterprise Linux 8 starting with RHEL-8.1.0, that is Red Hat Enterprise Linux 8.1 GA kernel version.

Comment 13 errata-xmlrpc 2020-07-21 11:04:45 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:3010 https://access.redhat.com/errata/RHSA-2020:3010

Comment 14 errata-xmlrpc 2020-07-21 11:23:00 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:3016 https://access.redhat.com/errata/RHSA-2020:3016

Comment 15 Product Security DevOps Team 2020-07-21 13:27:42 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-2019-19807

Comment 16 errata-xmlrpc 2020-07-29 19:37:15 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.1 Extended Update Support

Via RHSA-2020:3222 https://access.redhat.com/errata/RHSA-2020:3222

Comment 17 errata-xmlrpc 2020-09-29 18:59:03 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4062 https://access.redhat.com/errata/RHSA-2020:4062

Comment 18 errata-xmlrpc 2020-09-29 20:52:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4060 https://access.redhat.com/errata/RHSA-2020:4060