Bug 2375304 (CVE-2025-38085)

Summary:	CVE-2025-38085 kernel: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race
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 2025-06-28 08:01:11 UTC

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

mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race

huge_pmd_unshare() drops a reference on a page table that may have
previously been shared across processes, potentially turning it into a
normal page table used in another process in which unrelated VMAs can
afterwards be installed.

If this happens in the middle of a concurrent gup_fast(), gup_fast() could
end up walking the page tables of another process.  While I don't see any
way in which that immediately leads to kernel memory corruption, it is
really weird and unexpected.

Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(),
just like we do in khugepaged when removing page tables for a THP
collapse.

Comment 1 Avinash Hanwate 2025-06-30 02:54:28 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025062836-CVE-2025-38085-8075@gregkh/T

Comment 3 errata-xmlrpc 2025-08-11 09:39:33 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2025:13590 https://access.redhat.com/errata/RHSA-2025:13590

Comment 4 errata-xmlrpc 2025-08-11 09:45:17 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2025:13589 https://access.redhat.com/errata/RHSA-2025:13589

Comment 5 errata-xmlrpc 2025-08-11 10:08:40 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2025:13598 https://access.redhat.com/errata/RHSA-2025:13598

Comment 6 errata-xmlrpc 2025-08-18 04:07:55 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:13962 https://access.redhat.com/errata/RHSA-2025:13962

Comment 7 errata-xmlrpc 2025-09-02 01:46:59 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-2025:14985 https://access.redhat.com/errata/RHSA-2025:14985

Comment 8 errata-xmlrpc 2025-09-04 01:15:28 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2025:15224 https://access.redhat.com/errata/RHSA-2025:15224

Comment 9 errata-xmlrpc 2025-09-04 01:45:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2025:15227 https://access.redhat.com/errata/RHSA-2025:15227

Comment 11 errata-xmlrpc 2025-09-10 16:13:47 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-2025:15647 https://access.redhat.com/errata/RHSA-2025:15647

Comment 12 errata-xmlrpc 2025-09-10 20:42:23 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2025:15658 https://access.redhat.com/errata/RHSA-2025:15658

Comment 13 errata-xmlrpc 2025-09-11 01:48:55 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-2025:15660 https://access.redhat.com/errata/RHSA-2025:15660

Comment 14 errata-xmlrpc 2025-09-11 06:36:04 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

Via RHSA-2025:15668 https://access.redhat.com/errata/RHSA-2025:15668

Comment 15 errata-xmlrpc 2025-09-11 07:35:22 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2025:15670 https://access.redhat.com/errata/RHSA-2025:15670

Comment 23 errata-xmlrpc 2025-11-18 09:00:05 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Advanced Update Support

Via RHSA-2025:21667 https://access.redhat.com/errata/RHSA-2025:21667