Bug 1901161 (CVE-2020-15437)

Summary:	CVE-2020-15437 kernel: NULL pointer dereference in serial8250_isa_init_ports function in drivers/tty/serial/8250/8250_core.c
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
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, bhu, blc, bmasney, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, jonathan, josef, jross, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mcressma, mjg59, mlangsdo, nmurray, ptalbert, qzhao, rt-maint, rvrbovsk, steved, 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 UART 8250 functionality, in the way certain hardware architectures handled situations where default ports (0x2E8, 0x2F8, 0x3E8, 0x3F8) are not available. This flaw allows a local user to crash the system. The highest threat from this vulnerability is to system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-05-18 20:37:16 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:	1901162, 1903272, 1905052, 1905053
Bug Blocks:	1901164

Description Guilherme de Almeida Suckevicz 2020-11-24 16:19:06 UTC

The Linux kernel before version 5.8 is vulnerable to a NULL pointer dereference in drivers/tty/serial/8250/8250_core.c:serial8250_isa_init_ports() that allows local users to cause a denial of service by using the p->serial_in pointer which uninitialized.

Reference:
https://lkml.org/lkml/2020/7/21/80

Comment 1 Guilherme de Almeida Suckevicz 2020-11-24 16:20:59 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1901162]

Comment 2 Justin M. Forbes 2020-11-25 14:42:38 UTC

This was fixed for Fedora with the 5.7.11 stable kernel updates.

Comment 4 Alex 2020-12-01 18:02:48 UTC

Statement:

This flaw is rated as having a Moderate impact because the issue can only be triggered by an authorized local user in the tty or in the dialout group.

Comment 8 errata-xmlrpc 2021-05-18 13:20:37 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1578 https://access.redhat.com/errata/RHSA-2021:1578

Comment 9 errata-xmlrpc 2021-05-18 14:40:56 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1739 https://access.redhat.com/errata/RHSA-2021:1739

Comment 10 Product Security DevOps Team 2021-05-18 20:37:16 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-2020-15437