Bug 2112693 (CVE-2020-36558)

Summary:	CVE-2020-36558 kernel: race condition in VT_RESIZEX ioctl when vc_cons[i].d is already NULL leading to NULL pointer dereference
Product:	[Other] Security Response	Reporter:	Alex <allarkin>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bdettelb, bhu, brdeoliv, bskeggs, chwhite, crwood, ddepaula, dhoward, dvlasenk, fhrbata, hdegoede, hkrzesin, hpa, jaeshin, jarod, jarodwilson, jburrell, jfaracco, jferlan, jforbes, jglisse, jlelli, joe.lawrence, jonathan, josef, jshortt, jstancek, jwboyer, jwyatt, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, lzampier, masami256, mchehab, mrehak, nmurray, ptalbert, qzhao, rvrbovsk, scweaver, steved, tyberry, vkumar, walters, williams
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 NULL pointer dereference flaw was found in the Linux kernel’s Virtual Terminal subsystem was found in how a user calls the VT_RESIZEX ioctl. This flaw allows a local user to crash the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-12-04 05:04:02 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:	2068338, 2112694, 2112695, 2112696, 2112697, 2233515, 2274389
Bug Blocks:	2109700

Description Alex 2022-07-31 17:29:56 UTC

A NULL pointer dereference vulnerability was found in drivers/tty/vt/vt_ioctl.c in the Linux kernel before 5.5.7.
A race condition when call to VT_RESIZEX ioctl and vc_cons[i].d is already NULL could lead to crash.

Reference:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6cd1ed50efd88261298577cd92a14f2768eddeeb

Comment 3 errata-xmlrpc 2022-11-08 09:10:23 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:7444 https://access.redhat.com/errata/RHSA-2022:7444

Comment 4 errata-xmlrpc 2022-11-08 10:09:58 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:7683 https://access.redhat.com/errata/RHSA-2022:7683

Comment 5 Product Security DevOps Team 2022-12-04 05:03:58 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-2020-36558

Comment 11 errata-xmlrpc 2023-10-10 16:26:08 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Extended Update Support

Via RHSA-2023:5627 https://access.redhat.com/errata/RHSA-2023:5627

Comment 13 Alex 2024-04-10 19:20:43 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2274389]

Comment 16 errata-xmlrpc 2024-04-23 15:42:58 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2024:2003 https://access.redhat.com/errata/RHSA-2024:2003

Comment 17 errata-xmlrpc 2024-04-23 16:38:48 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2024:2004 https://access.redhat.com/errata/RHSA-2024:2004