Bug 2282361 (CVE-2021-47379)

Summary:	CVE-2021-47379 kernel: blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd
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, 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 5.4.150, kernel 5.10.70, kernel 5.14.9, kernel 5.15	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in the Linux kernel's blk-cgroup subsystem, where a use-after-free error occured when the kernel may incorrectly access memory after it has been freed. This happens when certain operations on block group data structures are not properly synchronized, allowing other processes to use memory that has already been deallocated, potentially causing system crashes or instability.	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:	2282406

Description ybuenos 2024-05-22 09:27:44 UTC

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

blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd

The Linux kernel CVE team has assigned CVE-2021-47379 to this issue.

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024052142-CVE-2021-47379-58ec@gregkh/T

Comment 1 Alex 2024-06-09 15:41:42 UTC

The result of automatic check (that is developed by Alexander Larkin) for this CVE-2021-47379 is: CHECK	Maybe valid. Check manually. with impact MODERATE (that is approximation based on flags READ KASAN LOCK UAF  ; these flags parsed automatically based on patche 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.