Bug 2088021 (CVE-2022-29581)

Summary:	CVE-2022-29581 kernel: use-after-free due to improper update of reference count in net/sched/cls_u32.c
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, bskeggs, chwhite, ddepaula, dhoward, dvlasenk, fhrbata, hdegoede, hkrzesin, hpa, jarod, jarodwilson, jburrell, jfaracco, jferlan, jforbes, jglisse, jlelli, joe.lawrence, jonathan, josef, jpazdziora, jshortt, jstancek, jwboyer, jwyatt, kcarcia, kernel-maint, kernel-mgr, kyoshida, lgoncalv, linville, lzampier, masami256, mchehab, nmurray, ptalbert, qzhao, rkeshri, rvrbovsk, scweaver, steved, swood, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.18 rc4	Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free flaw was found in u32_change in net/sched/cls_u32.c in the network subcomponent of the Linux kernel. This flaw allows a local attacker to crash the system, cause a privilege escalation, and leak kernel information.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-12-05 08:36:23 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:	2080193, 2081283, 2088023, 2089109, 2089110, 2089111, 2089112, 2090410
Bug Blocks:	2088024

Description Guilherme de Almeida Suckevicz 2022-05-18 16:50:07 UTC

A use-after-free flaw was found in u32_change in net/sched/cls_u32.c in the network subcomponent of the Linux kernel.  This flaw could allow a local attacker to crash the system and cause a privilege escalation, and a kernel information leak problem.

References and upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3db09e762dc79584a69c10d74a6b98f89a9979f8
https://kernel.dance/#3db09e762dc79584a69c10d74a6b98f89a9979f8

Comment 1 Guilherme de Almeida Suckevicz 2022-05-18 16:51:44 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2088023]

Comment 2 Justin M. Forbes 2022-05-18 18:53:29 UTC

This was fixed for fedora with the 5.17.5 stable kernel update.

Comment 12 errata-xmlrpc 2022-11-08 09:10:12 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:7444 https://access.redhat.com/errata/RHSA-2022:7444

Comment 13 errata-xmlrpc 2022-11-08 10:09:49 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:7683 https://access.redhat.com/errata/RHSA-2022:7683

Comment 14 errata-xmlrpc 2022-11-15 09:45:08 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2022:7933 https://access.redhat.com/errata/RHSA-2022:7933

Comment 15 errata-xmlrpc 2022-11-15 10:48:03 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2022:8267 https://access.redhat.com/errata/RHSA-2022:8267

Comment 16 Product Security DevOps Team 2022-12-05 08:36:19 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-2022-29581

Comment 17 Jan Pazdziora 2023-07-29 11:49:07 UTC

Hello,

the CVE page https://access.redhat.com/security/cve/CVE-2022-29581 says in the Mitigation section

  To mitigate this issue, prevent the module u32 from being loaded by blacklisting the module to prevent it from loading automatically.

However, at least on RHEL 9.0 and 8.6, module u32 does not exist. Instead, is it possible that cls_u32 should be mentioned in that text?

Thank you, Jan