Bug 1796939 (CVE-2020-8428)

Summary:	CVE-2020-8428 kernel: use-after-free in fs/namei.c
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, airlied, bdettelb, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, esandeen, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, qzhao, rt-maint, rvrbovsk, steved, williams, wmealing, 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 flaw was found in the Linux kernel. The may_create_in_sticky in fs/namei.c function has a possible use-after-free which can allow a local user to cause a denial of service (OOPS) or possibly obtain sensitive information from kernel memory. The highest threat from this vulnerability is to system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-09-24 14:41:06 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:	1796940
Bug Blocks:	1796943

Description Dhananjay Arunesh 2020-01-31 15:00:10 UTC

A vulnerability was found in may_create_in_sticky in fs/namei.c of Linux kernel which has a possible use-after-free. This can allow a local user to cause a denial of service (OOPS) or possibly obtain sensitive information from kernel memory. One attack vector may be an open system call for a UNIX domain socket if the socket file is being moved to a new parent directory and its old parent directory is being removed.

At this time no Red Hat products are affected by this flaw.

Reference:
http://www.openwall.com/lists/oss-security/2020/01/28/4
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d0cb50185ae942b03c4327be322055d622dc79f6
https://github.com/torvalds/linux/commit/d0cb50185ae942b03c4327be322055d622dc79f6
https://www.openwall.com/lists/oss-security/2020/01/28/2

Comment 1 Dhananjay Arunesh 2020-01-31 15:00:40 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1796940]

Comment 2 Justin M. Forbes 2020-02-03 22:35:24 UTC

This was fixed for Fedora with the 5.4.16 stable kernel updates.

Comment 5 Wade Mealing 2020-02-04 02:40:30 UTC

I have requested a backport of the security feature here: https://bugzilla.redhat.com/show_bug.cgi?id=1797843 for Red Hat Enterprise Linux 8.

Comment 6 Wade Mealing 2020-02-07 03:28:41 UTC

Just to be clear, Red Hat Enterprise 8 is -not- affected by this flaw, the security feature has the flaw.

Comment 8 Product Security DevOps Team 2020-09-24 14:41:06 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-2020-8428