Bug 1775182 (CVE-2019-19037)

Summary:	CVE-2019-19037 kernel: null-pointer dereference in ext4_empty_dir in fs/ext4/namei.c
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
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, allarkin, 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, 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 was found in the Linux kernel’s Ext4 FileSystem in the way it uses a crafted ext4 image. This flaw allows a local user with physical access to crash the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-25 22:15:36 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:	1775183, 1835720, 1835721, 1835722, 1835723, 1835724
Bug Blocks:	1775185

Description Dhananjay Arunesh 2019-11-21 14:30:36 UTC

A vulnerability was found in ext4_empty_dir in fs/ext4/namei.c in the Linux kernel allows a NULL pointer dereference because ext4_read_dirblock(inode,0,DIRENT_HTREE) can be zero.

Reference:
https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19037

Comment 1 Dhananjay Arunesh 2019-11-21 14:31:03 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1775183]

Comment 2 Justin M. Forbes 2020-03-19 21:56:09 UTC

This is fixed for Fedora with the 5.4.7 stable kernel updates.

Comment 8 Petr Matousek 2020-05-14 12:05:57 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 9 Petr Matousek 2020-05-14 12:11:51 UTC

Statement:

This issue is rated as having Low impact because of the preconditions needed to trigger the issue (physical access or user interaction to mount the crafted filesystem image).