Bug 1775746 (CVE-2019-18885)

Summary:	CVE-2019-18885 kernel: fs/btrfs/volumes.c allows a btrfs_verify_dev_extents NULL pointer dereference
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	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, jglisse, jlelli, john.j5live, jonathan, josef, jross, jschorr, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, plougher, qzhao, rt-maint, rvrbovsk, steved, 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:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-04-03 06:36:15 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:	1775747
Bug Blocks:	1775748

Description Guilherme de Almeida Suckevicz 2019-11-22 17:24:15 UTC

fs/btrfs/volumes.c in the Linux kernel before 5.1 allows a btrfs_verify_dev_extents NULL pointer dereference via a crafted btrfs image because fs_devices->devices is mishandled within find_device, aka CID-09ba3bc9dd15.

Reference:
https://github.com/bobfuzzer/CVE-2019-18885

Upstream commit:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=09ba3bc9dd150457c506e4661380a6183af651c1

Comment 1 Guilherme de Almeida Suckevicz 2019-11-22 17:25:19 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1775747]

Comment 2 Justin M. Forbes 2019-11-22 18:52:09 UTC

This was fixed for Fedora with the 5.1 kernel rebases.

Comment 3 Petr Matousek 2020-04-03 06:36:20 UTC

Statement:

The Btrfs was introduced as a Technology Preview in both Red Hat Enterprise Linux 6 and 7 but is currently deprecated and not supported in both Red Hat Enterprise Linux releases.