Bug 2414482 (CVE-2025-40168)

Summary:	CVE-2025-40168 kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match()
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	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel’s SMC (Shared Memory Communication) module: in smc_clc_prfx_match(), the function is called from smc_listen_work() without proper RCU or RTNL protection. The code previously used sk_dst_get(sk)->dev, which can lead to a use-after-free (UAF) condition if the sk’s destination is freed concurrently.	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 2025-11-12 11:02:38 UTC

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

smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match().

smc_clc_prfx_match() is called from smc_listen_work() and
not under RCU nor RTNL.

Using sk_dst_get(sk)->dev could trigger UAF.

Let's use __sk_dst_get() and dst_dev_rcu().

Note that the returned value of smc_clc_prfx_match() is not
used in the caller.

Comment 1 Alexander B 2025-11-13 15:48:15 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025111256-CVE-2025-40168-bdd5@gregkh/T

Comment 3 errata-xmlrpc 2026-02-16 11:50:22 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:2720 https://access.redhat.com/errata/RHSA-2026:2720

Comment 4 errata-xmlrpc 2026-02-17 12:46:25 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:2821 https://access.redhat.com/errata/RHSA-2026:2821

Comment 5 errata-xmlrpc 2026-02-25 01:49:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:3275 https://access.redhat.com/errata/RHSA-2026:3275

Comment 6 errata-xmlrpc 2026-03-02 02:59:25 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:3488 https://access.redhat.com/errata/RHSA-2026:3488

Comment 7 errata-xmlrpc 2026-03-09 16:42:11 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:4111 https://access.redhat.com/errata/RHSA-2026:4111

Comment 8 errata-xmlrpc 2026-04-08 03:32:13 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-2026:6954 https://access.redhat.com/errata/RHSA-2026:6954

Comment 9 errata-xmlrpc 2026-04-22 00:11:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Advanced Update Support

Via RHSA-2026:9513 https://access.redhat.com/errata/RHSA-2026:9513

Comment 10 errata-xmlrpc 2026-04-22 00:23:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.6 Telecommunications Update Service

Via RHSA-2026:9514 https://access.redhat.com/errata/RHSA-2026:9514

Comment 11 errata-xmlrpc 2026-04-22 07:51:55 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-2026:9643 https://access.redhat.com/errata/RHSA-2026:9643

Comment 15 errata-xmlrpc 2026-06-22 05:55:59 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:27708 https://access.redhat.com/errata/RHSA-2026:27708