Bug 1786179 (CVE-2019-19770)

Summary:	CVE-2019-19770 kernel: use-after-free in debugfs_remove in fs/debugfs/inode.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, airlied, bdettelb, bhu, blc, brdeoliv, bskeggs, dchinner, 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, rkeshri, rt-maint, rvrbovsk, sgrubb, steved, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---	Flags:	rkeshri: needinfo+
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free flaw was found in the debugfs_remove function in the Linux kernel. The flaw could allow a local attacker with special user (or root) privilege to crash the system at the time of file or directory removal. This vulnerability can lead to a kernel information leak. The highest threat from this vulnerability is to system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-11-04 02:23:53 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:	1890029, 1786181, 1816556, 1816557, 1816558, 1816559, 1816560, 1890026, 1890027, 1890028, 1890030
Bug Blocks:	1786180

Description Guilherme de Almeida Suckevicz 2019-12-23 18:08:49 UTC

A use-after-free flaw was found in the debugfs_remove function in the Linux kernel. The flaw could allow a local attacker with special user (or root) privilege to crash the system at the time of file or directory removal. This vulnerability can lead to a kernel information leak. The highest threat from this vulnerability is to system availability.

Reference:
https://bugzilla.kernel.org/show_bug.cgi?id=205713
https://lore.kernel.org/linux-block/20200402000002.7442-1-mcgrof@kernel.org/

Comment 1 Guilherme de Almeida Suckevicz 2019-12-23 18:09:38 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1786181]

Comment 17 Dave Chinner 2020-04-02 01:02:08 UTC

https://lore.kernel.org/linux-fsdevel/20200402000002.7442-1-mcgrof@kernel.org/T/#mc62cc15324d1da505c6a9c50e3363f4d20537d45

Looks like it's just a blktrace bug, not a critical security problem:

"We there would like to contend CVE-2019-19770 as invalid. The
implications suggested are not correct, and this issue is only
triggerable with root, by shooting yourself on the foot by misuing
blktrace."

-Dave.

Comment 23 Rohit Keshri 2020-05-15 07:49:53 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 26 errata-xmlrpc 2020-11-04 00:50:23 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4431 https://access.redhat.com/errata/RHSA-2020:4431

Comment 27 errata-xmlrpc 2020-11-04 02:22:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4609 https://access.redhat.com/errata/RHSA-2020:4609

Comment 28 Product Security DevOps Team 2020-11-04 02:23:53 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-2019-19770