Bug 2282554 (CVE-2021-47256)

Summary:	CVE-2021-47256 kernel: mm/memory-failure: make sure wait for page writeback in memory_failure
Product:	[Other] Security Response	Reporter:	ybuenos
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, allarkin, aquini, aubaker, bhu, chwhite, cye, cyin, dbohanno, debarbos, dfreiber, drow, dvlasenk, esandeen, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, ldoskova, lgoncalv, lzampier, mbenatto, mleitner, mmilgram, mstowell, nmurray, ptalbert, rparrazo, rrobaina, rvrbovsk, scweaver, sidakwo, sukulkar, tglozar, vkumar, wcosta, williams, wmealing, ycote, ykopkova, zhijwang
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 4.14.238, kernel 4.19.196, kernel 5.4.128, kernel 5.10.46, kernel 5.12.13, kernel 5.13	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in the memory_failure function in the Linux kernel's memory management system, where the system may not wait for certain pages to finish writing before performing actions on them, leading to a kernel crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:		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:
Bug Blocks:	2282973

Description ybuenos 2024-05-22 14:39:08 UTC

In the Linux kernel, the following vulnerability has been resolved:

mm/memory-failure: make sure wait for page writeback in memory_failure

The Linux kernel CVE team has assigned CVE-2021-47256 to this issue.

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024052146-CVE-2021-47256-a490@gregkh/T

Comment 3 Alex 2024-06-09 16:06:56 UTC

The result of automatic check (that is developed by Alexander Larkin) for this CVE-2021-47256 is: CHECK	Maybe valid. Check manually. with impact MODERATE (that is an approximation based on flags READ DANGER DISK  ; these flags parsed automatically based on patch data). Such automatic check happens only for Low/Moderates (and only when not from reporter, but parsing already existing CVE). Highs always checked manually (I check it myself and then we check it again in Remediation team). In rare cases some of the Moderates could be increased to High later.

Comment 11 Audra Mitchell 2024-07-17 13:18:33 UTC

Hey @Alex

I see that the reported already checked and noticed this fix is in RHEL 8:

$ kerneloscope downstream e8675d291ac0
944bd962177f (in rhel-8.5, rhel-8.6, rhel-8.7, rhel-8.8, rhel-8.9, rhel-8.10) mm/memory-failure: make sure wait for page writeback in memory_failure

Can you give me some insight into why we still opened trackers for this issue and what I am supposed to do with these trackers?

Thanks

Comment 12 Alex 2024-07-24 09:54:06 UTC

In reply to comment #11:
> Hey @Alex
> 
> I see that the reported already checked and noticed this fix is in RHEL 8:
> 
> $ kerneloscope downstream e8675d291ac0
> 944bd962177f (in rhel-8.5, rhel-8.6, rhel-8.7, rhel-8.8, rhel-8.9,
> rhel-8.10) mm/memory-failure: make sure wait for page writeback in
> memory_failure
> 
> Can you give me some insight into why we still opened trackers for this
> issue and what I am supposed to do with these trackers?
> 
> Thanks

Just close it. Starting from July all trackers created by default for all-streams (including Z-stream trackers) without prior manual check if affected or not. I closed rhel8 trackers.