Bug 1444493 (CVE-2017-7889)

Summary:	CVE-2017-7889 kernel: mm subsystem does not properly enforce the CONFIG_STRICT_DEVMEM protection mechanism
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	aquini, bhu, dhoward, fhrbata, gansalmon, hwkernel-mgr, iboverma, ichavero, itamar, jforbes, jkacur, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, madhu.chinakonda, matt, mchehab, mcressma, nmurray, pholasek, plougher, rt-maint, rvrbovsk, vdronov, williams, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	The mm subsystem in the Linux kernel through 4.10.10 does not properly enforce the CONFIG_STRICT_DEVMEM protection mechanism, which allows local users to read or write to kernel memory locations in the first megabyte (and bypass slab-allocation access restrictions) via an application that opens the /dev/mem file, related to arch/x86/mm/init.c and drivers/char/mem.c.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 03:11:01 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:	1444496, 1449676, 1449677, 1449678, 1449679
Bug Blocks:	1444498

Description Adam Mariš 2017-04-21 12:48:33 UTC

The mm subsystem in the Linux kernel through 4.10.10 does not properly enforce the CONFIG_STRICT_DEVMEM protection mechanism, which allows local users to read or write to kernel memory locations in the first megabyte (and bypass slab-allocation access restrictions) via an application that opens the /dev/mem file, related to arch/x86/mm/init.c and drivers/char/mem.c.

Discussion:

http://seclists.org/oss-sec/2017/q2/76

Upstream patch:

https://github.com/torvalds/linux/commit/a4866aa812518ed1a37d8ea0c881dc946409de94

Comment 1 Adam Mariš 2017-04-21 12:53:08 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1444496]

Comment 3 Vladis Dronov 2017-05-10 12:24:28 UTC

Statement:

This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 5. This is not currently planned to be addressed in future updates of the product due to its life cycle. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.

This issue affects the versions of the Linux kernel as shipped with
Red Hat Enterprise Linux 6, 7 and Red Hat Enterprise MRG 2. Future kernel
updates for Red Hat Enterprise Linux 6, 7 and Red Hat Enterprise MRG 2 may
address this issue.

Comment 8 errata-xmlrpc 2017-08-01 19:15:31 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:2077 https://access.redhat.com/errata/RHSA-2017:2077

Comment 9 errata-xmlrpc 2017-08-02 07:55:39 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:1842 https://access.redhat.com/errata/RHSA-2017:1842

Comment 10 errata-xmlrpc 2017-09-06 20:41:23 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise MRG 2

Via RHSA-2017:2669 https://access.redhat.com/errata/RHSA-2017:2669

Comment 11 errata-xmlrpc 2018-06-19 04:49:20 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2018:1854 https://access.redhat.com/errata/RHSA-2018:1854