Bug 2383922 (CVE-2025-38477)

Summary:	CVE-2025-38477 kernel: net/sched: sch_qfq: Fix race condition on qfq_aggregate
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:	---
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Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2025-07-28 12:03:25 UTC

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

net/sched: sch_qfq: Fix race condition on qfq_aggregate

A race condition can occur when 'agg' is modified in qfq_change_agg
(called during qfq_enqueue) while other threads access it
concurrently. For example, qfq_dump_class may trigger a NULL
dereference, and qfq_delete_class may cause a use-after-free.

This patch addresses the issue by:

1. Moved qfq_destroy_class into the critical section.

2. Added sch_tree_lock protection to qfq_dump_class and
qfq_dump_class_stats.

Comment 1 Avinash Hanwate 2025-07-28 17:26:36 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025072813-CVE-2025-38477-8b42@gregkh/T

Comment 5 errata-xmlrpc 2025-09-02 04:19:39 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2025:15008 https://access.redhat.com/errata/RHSA-2025:15008

Comment 6 errata-xmlrpc 2025-09-30 00:32:40 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-2025:17009 https://access.redhat.com/errata/RHSA-2025:17009

Comment 7 errata-xmlrpc 2025-09-30 17:21:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2025:17109 https://access.redhat.com/errata/RHSA-2025:17109

Comment 8 errata-xmlrpc 2025-10-01 00:24:47 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-2025:17124 https://access.redhat.com/errata/RHSA-2025:17124

Comment 9 errata-xmlrpc 2025-10-01 17:40:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2025:17161 https://access.redhat.com/errata/RHSA-2025:17161