Bug 1553911 (CVE-2018-7995)

Summary:	CVE-2018-7995 kernel: Race condition in the store_int_with_restart() function in cpu/mcheck/mce.c
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	airlied, ajax, aquini, bhu, blc, bskeggs, dhoward, esammons, ewk, fhrbata, hdegoede, hkrzesin, hwkernel-mgr, iboverma, ichavero, itamar, jarodwilson, jforbes, jglisse, jkacur, john.j5live, jonathan, josef, jross, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, lwang, matt, mchehab, mcressma, mguzik, mjg59, mlangsdo, nmurray, plougher, rt-maint, rvrbovsk, skozina, slawomir, steved, vdronov, williams, yozone
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 race condition in the store_int_with_restart() function in arch/x86/kernel/cpu/mcheck/mce.c in the Linux kernel allows local users to cause a denial of service (panic) by leveraging root access to write to the check_interval file in a /sys/devices/system/machinecheck/machinecheck<cpu number> directory.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-03-22 11:47:45 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:	1553918
Bug Blocks:	1553913

Description Pedro Sampaio 2018-03-09 21:04:02 UTC

Race condition in the store_int_with_restart() function in arch/x86/kernel/cpu/mcheck/mce.c in the Linux kernel allows local users to cause a denial of service (panic) by leveraging root access to write to the check_interval file in a /sys/devices/system/machinecheck/machinecheck<cpu number> directory.

References:

https://lkml.org/lkml/2018/3/2/970

An upsteam patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3b7c4795ccab5be71f080774c45bbbcc75c2aaf

Comment 1 Pedro Sampaio 2018-03-09 21:20:12 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1553918]

Comment 2 Fedora Update System 2018-03-16 16:18:33 UTC

kernel-4.15.9-200.fc26 has been pushed to the Fedora 26 stable repository. If problems still persist, please make note of it in this bug report.

Comment 4 Vladis Dronov 2018-03-22 11:42:57 UTC

Notes:

Since only root can write to the mentioned sysfs variables, the issue is not a security flaw.