Bug 1406085 (CVE-2016-7916)

Summary:	CVE-2016-7916 kernel: proc: prevent accessing /proc/<pid>/environ until it's ready
Product:	[Other] Security Response	Reporter:	Vladis Dronov <vdronov>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	aquini, bhu, dhoward, fhrbata, iboverma, jkacur, joelsmith, jross, kernel-mgr, lgoncalv, mcressma, nmurray, pholasek, rt-maint, rvrbovsk, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	Race condition in the environ_read() function in 'fs/proc/base.c' in the Linux kernel before 4.5.4 allows local users to obtain sensitive information from kernel memory by reading a '/proc/*/environ' file during a process-setup time interval in which environment-variable copying is incomplete.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-21 11:49:50 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:	1406088
Bug Blocks:	1395269

Description Vladis Dronov 2016-12-19 16:41:47 UTC

Race condition in the environ_read() function in 'fs/proc/base.c' in the Linux kernel before 4.5.4 allows local users to obtain sensitive information from kernel memory by reading a '/proc/*/environ' file during a process-setup time interval in which environment-variable copying is incomplete.

References:

https://forums.grsecurity.net/viewtopic.php?f=3&t=4363

https://bugzilla.kernel.org/show_bug.cgi?id=116461

http://source.android.com/security/bulletin/2016-11-01.html

https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-7916

Upstream patch:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8148a73c9901a8794a50f950083c00ccf97d43b3

Comment 4 Vladis Dronov 2016-12-19 16:57:33 UTC

Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6 as the code with the flaw is not present in the products listed.

This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 7 and Red Hat Enterprise MRG-2. This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.