Bug 2283392 (CVE-2021-47557)

Summary:	CVE-2021-47557 kernel: net/sched: sch_ets: don't peek at classes beyond 'nbands'
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, mleitner, mmilgram, mstowell, nmurray, ptalbert, rkeshri, rparrazo, rrobaina, rvrbovsk, rysulliv, scweaver, sidakwo, sukulkar, tglozar, tyberry, vkumar, wcosta, williams, wmealing, ycote, ykopkova, zhijwang
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.10.83, kernel 5.15.6, kernel 5.16	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in the Linux kernel's net/sched implementation, in the ETS module, where the system attempts to access classes beyond the defined limits, leading to a potential NULL pointer dereference. As a result, this can cause system crashes, disrupt network traffic.	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:	2283496

Description ybuenos 2024-05-27 09:39:17 UTC

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

net/sched: sch_ets: don&#39;t peek at classes beyond &#39;nbands&#39;

The Linux kernel CVE team has assigned CVE-2021-47557 to this issue.

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024052444-CVE-2021-47557-bc88@gregkh/T

Comment 2 Alex 2024-06-09 16:13:57 UTC

The result of automatic check (that is developed by Alexander Larkin) for this CVE-2021-47557 is: CHECK	Maybe valid. Check manually. with impact MODERATE (that is an approximation based on flags REMOTE DANGER NULLPTR DISK INIT RACE NETWORK SKB  ; 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.