medium 4.7

CVE-2025-38681 json

mm/ptdump: take the memory hotplug lock inside ptdump_walk_pgd()

published 2025-09-04 14 mo ago modified 2026-11-05 3 d ago also EUVD-2025-26788

cvss: 4.7; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits: 0; none known

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

Memory hot remove unmaps and tears down various kernel page table regions as required. The ptdump code can race with concurrent modifications of the kernel page tables. When leaf entries are modified concurrently, the dump code may log stale or inconsistent information for a VA range, but this is otherwise not harmful.

But when intermediate levels of kernel page table are freed, the dump code will continue to use memory that has been freed and potentially reallocated for another purpose. In such cases, the ptdump code may dereference bogus addresses, leading to a number of potential problems.

To avoid the above mentioned race condition, platforms such as arm64, riscv and s390 take memory hotplug lock, while dumping kernel page table via the sysfs interface /sys/kernel/debug/kernel_page_tables.

Similar race condition exists while checking for pages that might have been marked W+X via /sys/kernel/debug/kernel_page_tables/check_wx_pages which in turn calls ptdump_check_wx(). Instead of solving this race condition again, let's just move the memory hotplug lock inside generic ptdump_check_wx() which will benefit both the scenarios.

Drop get_online_mems() and put_online_mems() combination from all existing platform ptdump code paths.

Patch / fix

fixed in 2 distros 5 links 8

Linux Linux 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2, 6.17
Siemens SIMATIC CN 4100 V5.0

debian ubuntu suse opensuse azure linux

linux Debian 12 6.1.153-1
linux Debian 13 6.12.43-1
linux Debian 14 6.16.3-1

debian advisories DEBIAN-CVE-2025-38681

linux Ubuntu 22.04 LTS 5.15.0-163.173
linux Ubuntu 24.04 LTS 6.8.0-100.100
linux-aws Ubuntu 22.04 LTS 5.15.0-1097.104
linux-aws Ubuntu 24.04 LTS 6.8.0-1046.49
linux-gcp Ubuntu 22.04 LTS 5.15.0-1097.106
linux-gcp Ubuntu 24.04 LTS 6.8.0-1047.50
linux-gke Ubuntu 22.04 LTS 5.15.0-1093.99
linux-gke Ubuntu 24.04 LTS 6.8.0-1043.48

ubuntu advisories UBUNTU-CVE-2025-38681

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel-rt Linux Micro 6.2 6.12.0-160000.6.1
kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1
kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1
kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.6.1
kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1.160000.2.4
kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1
kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.6.1
kernel-kvmsmall SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.6.1

suse advisories SUSE-SU-2025:21074-1 SUSE-SU-2025:21139-1 SUSE-SU-2026:20560-1 SUSE-SU-2025:21179-1 SUSE-SU-2025:4141-1 SUSE-SU-2025:4132-1

kernel-rt openSUSE Leap 16.0 6.12.0-160000.6.1
dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.6.1
kernel-64kb openSUSE Leap 16.0 6.12.0-160000.6.1
kernel-syms openSUSE Leap 16.0 6.12.0-160000.6.1
kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.6.1
kernel-source openSUSE Leap 16.0 6.12.0-160000.6.1
kernel-default openSUSE Leap 16.0 6.12.0-160000.6.1
kernel-kvmsmall openSUSE Leap 16.0 6.12.0-160000.6.1

opensuse advisories openSUSE-SU-2025:20081-1

kernel Azure Linux 3.0 6.6.104.2-1

azure linux advisories AZL-66815

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-38681 updated 2026-11-05 cvss 6.5

kernel: mm/ptdump: take the memory hotplug lock inside ptdump_walk_pgd()

Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
affected: no fix available “Fix deferred”
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-26-295-11 updated 2026-10-22 cvss 6.5

Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.7 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.7
affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-26-209-04 updated 2026-07-28 cvss 6.5

Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.6 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.6
affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-26-134-10 updated 2026-05-14 cvss 6.5

Siemens SIMATIC

Siemens SIMATIC CN 4100 < 5.0
affected: fixed in V5.0 support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 d ago (2026-11-05)

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	4.7	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

Linux Linux
Siemens SIMATIC CN 4100
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness

CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2025-38681
NVD CVE-2025-38681

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary

Patch / fix

Vendor advisories

CISA SSVC

Exploit prediction

CVSS scores

Affected products

Classification

References

Sources