Bug 2018205 (CVE-2021-0941)

Summary:	CVE-2021-0941 kernel: out-of-bounds read in bpf_skb_change_head() of filter.c due to a use-after-free
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bdettelb, bhu, brdeoliv, bskeggs, chwhite, crwood, dfreiber, dhoward, doconnor, drow, dvlasenk, fhrbata, fpacheco, hdegoede, hkrzesin, jarod, jarodwilson, jburrell, jeremy, jforbes, jglisse, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, nmurray, ptalbert, qzhao, rkeshri, rogbas, rvrbovsk, steved, teagle, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Kernel 5.12	Doc Type:	If docs needed, set a value
Doc Text:	An out-of-bounds (OOB) memory access flaw was found in net/core/filter.c in __bpf_skb_max_len in the Linux kernel. A missing sanity check to the current MTU check may allow a local attacker with special user privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-05-11 04:16:25 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:	1947006, 2018206, 2018252, 2018253, 2019556
Bug Blocks:	2018207

Description Guilherme de Almeida Suckevicz 2021-10-28 14:04:25 UTC

An out-of-bounds (OOB) memory access flaw was found in net/core/filter.c in __bpf_skb_max_len in the Linux kernel. A missing sanity check to the current MTU check may allow a local attacker with special user privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information.

References:
https://source.android.com/security/bulletin/pixel/2021-10-01
https://android.googlesource.com/kernel/common/+/6306c1189e77a513bf02720450bb43bd4ba5d8ae

Comment 1 Guilherme de Almeida Suckevicz 2021-10-28 14:05:28 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2018206]

Comment 7 Justin M. Forbes 2021-11-02 21:05:26 UTC

This was fixed for Fedora with the 5.11.12 stable kernel updates.

Comment 10 errata-xmlrpc 2022-05-10 14:40:09 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1975 https://access.redhat.com/errata/RHSA-2022:1975

Comment 11 errata-xmlrpc 2022-05-10 14:46:03 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1988 https://access.redhat.com/errata/RHSA-2022:1988

Comment 12 Product Security DevOps Team 2022-05-11 04:16:21 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-2021-0941