Bug 2461107 (CVE-2026-31532)

Summary:	CVE-2026-31532 kernel: can: raw: fix ro->uniq use-after-free in raw_rcv()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's Controller Area Network (CAN) raw socket implementation. A use-after-free vulnerability can occur due to a timing window during the unregistration of CAN receive filters, allowing a freed memory region to be accessed. This could lead to system instability or a denial of service (DoS).	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:

Description OSIDB Bzimport 2026-04-23 12:01:20 UTC

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

can: raw: fix ro->uniq use-after-free in raw_rcv()

raw_release() unregisters raw CAN receive filters via can_rx_unregister(),
but receiver deletion is deferred with call_rcu(). This leaves a window
where raw_rcv() may still be running in an RCU read-side critical section
after raw_release() frees ro->uniq, leading to a use-after-free of the
percpu uniq storage.

Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific
socket destructor. can_rx_unregister() takes an extra reference to the
socket and only drops it from the RCU callback, so freeing uniq from
sk_destruct ensures the percpu area is not released until the relevant
callbacks have drained.

[mkl: applied manually]

Comment 1 Alexander B 2026-04-23 15:02:20 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042349-CVE-2026-31532-a820@gregkh/T

Comment 3 errata-xmlrpc 2026-05-06 08:16:14 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

Via RHSA-2026:13932 https://access.redhat.com/errata/RHSA-2026:13932

Comment 4 errata-xmlrpc 2026-05-06 20:41:05 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:14339 https://access.redhat.com/errata/RHSA-2026:14339

Comment 5 errata-xmlrpc 2026-05-11 00:29:56 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:15883 https://access.redhat.com/errata/RHSA-2026:15883

Comment 7 errata-xmlrpc 2026-05-20 04:05:04 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2026:19521 https://access.redhat.com/errata/RHSA-2026:19521

Comment 8 errata-xmlrpc 2026-05-20 12:57:40 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:19568 https://access.redhat.com/errata/RHSA-2026:19568

Comment 9 errata-xmlrpc 2026-05-20 14:21:50 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2026:19705 https://access.redhat.com/errata/RHSA-2026:19705

Comment 10 errata-xmlrpc 2026-05-20 15:44:05 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2026:19711 https://access.redhat.com/errata/RHSA-2026:19711

Comment 11 errata-xmlrpc 2026-05-20 23:34:08 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:19875 https://access.redhat.com/errata/RHSA-2026:19875

Comment 12 errata-xmlrpc 2026-05-21 12:37:50 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2026:20130 https://access.redhat.com/errata/RHSA-2026:20130

Comment 13 errata-xmlrpc 2026-05-26 05:47:40 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:20593 https://access.redhat.com/errata/RHSA-2026:20593