Bug 1671869 (CVE-2016-10741)

Summary:	CVE-2016-10741 kernel: race condition between direct and memory-mapped I/O in fs/xfs/xfs_aops.c
Product:	[Other] Security Response	Reporter:	Laura Pardo <lpardo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	vdronov, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel-3.10.0-543.el7	Doc Type:	If docs needed, set a value
Doc Text:	It was found that the Linux kernel can hit a BUG_ON() statement in the __xfs_get_blocks() in the fs/xfs/xfs_aops.c because of a race condition between direct and memory-mapped I/O associated with a hole in a file that is handled with BUG_ON() instead of an I/O failure. This allows a local unprivileged attacker to cause a system crash and a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-02-04 17:17:48 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:	1364856
Bug Blocks:	1671871

Description Laura Pardo 2019-02-01 22:47:33 UTC

It was found that the Linux kernel can hit a BUG_ON() statement in the __xfs_get_blocks() in the fs/xfs/xfs_aops.c because there is a race condition possible between direct and memory-mapped I/O associated with a hole in a file that is handled with BUG_ON() instead of an I/O failure. This allows a local unprivileged attacker to cause a system crash and a denial-of-service.

References:

https://bugzilla.suse.com/show_bug.cgi?id=1124010

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.3

An upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=04197b341f23b908193308b8d63d17ff23232598