Bug 1781839 (CVE-2019-19462)

Summary:	CVE-2019-19462 kernel: NULL pointer dereference in relay_open in kernel/relay.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:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	acaringi, airlied, bdettelb, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mcressma, mjg59, mlangsdo, nmurray, qzhao, rt-maint, rvrbovsk, steved, vdronov, 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 may occur in the Linux kernel’s relay_open in kernel/relay.c. if the alloc_percpu() function is not validated in time of failure and used as a valid address for access. An attacker could use this flaw to cause a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-25 22:14:57 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:	1781840, 1804875, 1804876, 1804877
Bug Blocks:	1781841

Description Guilherme de Almeida Suckevicz 2019-12-10 16:47:16 UTC

relay_open in kernel/relay.c in the Linux kernel through 5.4.1 allows local users to cause a denial of service (such as relay blockage) by triggering a NULL alloc_percpu result.

Reference and upstream commit:
https://lore.kernel.org/lkml/20191129013745.7168-1-dja@axtens.net/

Comment 1 Guilherme de Almeida Suckevicz 2019-12-10 16:52:25 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1781840]

Comment 4 Rohit Keshri 2020-02-19 19:19:32 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 6 Vladis Dronov 2020-02-20 03:10:14 UTC

An upstream commit v2:

https://lore.kernel.org/lkml/20191219121256.26480-1-dja@axtens.net/

Comment 10 Justin M. Forbes 2020-10-08 19:07:06 UTC

This was fixed for Fedora with the 5.6.17 stable kernel updates.