Bug 1738711 (CVE-2018-20854)

Summary:	CVE-2018-20854 kernel: Out-of-bounds read in drivers/phy/mscc/phy-ocelot-serdes.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:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, airlied, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, plougher, rt-maint, rvrbovsk, steved, williams, wmealing
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 flaw was found in the Linux kernel’s implementation of ocelot-serdes hardware. An incorrect limits calculation allowed an off-by-one calculation, which could read out of bounds data and panic the system. If the data was not out of bounds, the following code could then write data into the out of bounds area, corrupting memory or other possible consequences.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-11-21 07:04:49 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:	1738712
Bug Blocks:	1738713

Description Pedro Sampaio 2019-08-07 22:26:41 UTC

An issue was discovered in the Linux kernels implementation of ocelot-serdes hardware. An incorrect limits calculation allowed an off-by-one calculation which could read out of bounds data and panic the system.  If the data was not out of bounds the following code could then write data into the out-of-bounds area corrupting memory or possibly other consequences.

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6acb47d1a318e5b3b7115354ebc4ea060c59d3a1
https://github.com/torvalds/linux/commit/6acb47d1a318e5b3b7115354ebc4ea060c59d3a1

Comment 1 Pedro Sampaio 2019-08-07 22:27:00 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1738712]

Comment 2 Justin M. Forbes 2019-08-08 09:28:31 UTC

This was fixed in Fedora with the 4.20 stable kernel update.

Comment 5 Wade Mealing 2019-11-21 05:05:05 UTC

Mitigation:

There is no requirement for mitigation at this time as this flaw does not affect shipping releases of Red Hat Enterprise Linux

Comment 6 Product Security DevOps Team 2019-11-21 07:04:49 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2018-20854