Bug 1849005 (CVE-2019-20794)

Summary:	CVE-2019-20794 kernel: task processes not being properly ended could lead to resource exhaustion
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, airlied, bhu, blc, bmasney, dvlasenk, hdegoede, hkrzesin, ichavero, itamar, jarodwilson, jeremy, jforbes, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mjg59, mlangsdo, nmurray, ptalbert, qzhao, rkeshri, 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 flaw was found in the Linux kernel. A user with PID namespace mounting a FUSE filesystem could cause a denial of service if the userspace component is terminated (pid 1). The highest threat from this vulnerability is to system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:		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:	1849006, 1867711, 1867712, 1867713, 1867714, 1867715, 1911196
Bug Blocks:	1849008

Description Marian Rehak 2020-06-19 13:09:23 UTC

A flaw was found when a user with PID namespace mounting a FUSE filesystem, If the userspace component is terminated (pid 1), this results into a denial of service (DoS) problem. This internally makes the fuse requests go into Uninterruptiblein state until the system is rebooted.

Reference:

https://github.com/sargun/fuse-example

Comment 1 Marian Rehak 2020-06-19 13:10:12 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1849006]

Comment 8 Alexey Gladkov 2020-10-07 10:02:28 UTC

Possible fix: https://lore.kernel.org/lkml/0c3dde5aaaaba58125e026a93749ecae4fdf2316.1601562271.git.gladkov.alexey@gmail.com/