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Fencer Vulns
medium 5.5

CVE-2025-37958 json

mm/huge_memory: fix dereferencing invalid pmd migration entry

published 2025-05-20 17 mo ago modified 2026-11-05 3 d ago also EUVD-2025-15893

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

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

mm/huge_memory: fix dereferencing invalid pmd migration entry

When migrating a THP, concurrent access to the PMD migration entry during a deferred split scan can lead to an invalid address access, as illustrated below. To prevent this invalid access, it is necessary to check the PMD migration entry and return early. In this context, there is no need to use pmd_to_swp_entry and pfn_swap_entry_to_page to verify the equality of the target folio. Since the PMD migration entry is locked, it cannot be served as the target.

Mailing list discussion and explanation from Hugh Dickins: "An anon_vma lookup points to a location which may contain the folio of interest, but might instead contain another folio: and weeding out those other folios is precisely what the "folio != pmd_folio((*pmd)" check (and the "risk of replacing the wrong folio" comment a few lines above it) is for."

BUG: unable to handle page fault for address: ffffea60001db008 CPU: 0 UID: 0 PID: 2199114 Comm: tee Not tainted 6.14.0+ #4 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:split_huge_pmd_locked+0x3b5/0x2b60 Call Trace: <TASK> try_to_migrate_one+0x28c/0x3730 rmap_walk_anon+0x4f6/0x770 unmap_folio+0x196/0x1f0 split_huge_page_to_list_to_order+0x9f6/0x1560 deferred_split_scan+0xac5/0x12a0 shrinker_debugfs_scan_write+0x376/0x470 full_proxy_write+0x15c/0x220 vfs_write+0x2fc/0xcb0 ksys_write+0x146/0x250 do_syscall_64+0x6a/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The bug is found by syzkaller on an internal kernel, then confirmed on upstream.

Patch / fix

  • Linux Linux 5.4.295, 5.10.239, 5.15.186, 6.1.142, 6.6.95, 6.12.29, 6.14.7, 6.15
  • linux Debian 12 6.1.147-1
  • linux Debian 14, Debian 13 6.12.29-1

debian advisories DEBIAN-CVE-2025-37958

  • linux Ubuntu 22.04 LTS 5.15.0-156.166
  • linux Ubuntu 24.04 LTS 6.8.0-90.91
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1092.99
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1044.46
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1092.101
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1045.48
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1089.95
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1041.46

ubuntu advisories UBUNTU-CVE-2025-37958

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 RHEL 9 5.14.0-570.30.1.el9_6
  • rv RHEL 9 5.14.0-570.30.1.el9_6
  • perf RHEL 9 5.14.0-570.30.1.el9_6
  • rtla RHEL 9 5.14.0-570.30.1.el9_6
  • libperf RHEL 9 5.14.0-570.30.1.el9_6
  • kernel-rt RHEL 9 5.14.0-570.30.1.el9_6
  • kernel-64k RHEL 9 5.14.0-570.30.1.el9_6
  • kernel-core RHEL 9 5.14.0-570.30.1.el9_6

red hat advisories RHSA-2025:13135RHSA-2025:12526RHSA-2025:12525RHSA-2025:12311RHSA-2025:12209RHSA-2025:11861

  • kernel-rt SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.179.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 5.14.21-150400.24.179.1

suse advisories SUSE-SU-2025:3761-1SUSE-SU-2025:3716-1SUSE-SU-2025:03628-1SUSE-SU-2025:03615-1SUSE-SU-2025:02000-1SUSE-SU-2025:01972-1

  • kernel AlmaLinux 9 5.14.0-570.30.1.el9_6
  • rv AlmaLinux 9 5.14.0-570.30.1.el9_6
  • perf AlmaLinux 9 5.14.0-570.30.1.el9_6
  • rtla AlmaLinux 9 5.14.0-570.30.1.el9_6
  • libperf AlmaLinux 9 5.14.0-570.30.1.el9_6
  • kernel-rt AlmaLinux 9 5.14.0-570.30.1.el9_6
  • kernel-64k AlmaLinux 9 5.14.0-570.30.1.el9_6
  • kernel-core AlmaLinux 9 5.14.0-570.30.1.el9_6

almalinux advisories ALSA-2025:11861ALSA-2025:11428

  • kernel Rocky Linux 9 5.14.0-570.30.1.el9_6
  • kernel Rocky Linux 10 6.12.0-55.22.1.el10_0

rocky linux advisories RLSA-2025:11861RLSA-2025:11428

  • kernel Azure Linux 3.0 6.6.96.1-1

azure linux advisories AZL-62779

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-2025-37958 updated cvss 4.7

kernel: mm/huge_memory: fix dereferencing invalid pmd migration entry

  • 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
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.81.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.81.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.81.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.81.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.81.1.el9_4
    fixed: vendor fix RHSA-2025:13135
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-570.30.1.el9_6, perf 5.14.0-570.30.1.el9_6, rtla 5.14.0-570.30.1.el9_6, python3-perf 5.14.0-570.30.1.el9_6, kernel-devel-matched 5.14.0-570.30.1.el9_6, kernel-64k-devel-matched 5.14.0-570.30.1.el9_6, +7 more
    fixed: vendor fix RHSA-2025:11861
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-55.22.1.el10_0, perf 6.12.0-55.22.1.el10_0, rtla 6.12.0-55.22.1.el10_0, python3-perf 6.12.0-55.22.1.el10_0, kernel-devel-matched 6.12.0-55.22.1.el10_0, kernel-64k-devel-matched 6.12.0-55.22.1.el10_0, +7 more
    fixed: vendor fix RHSA-2025:11428
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) perf 5.14.0-70.140.1.el9_0, kernel-devel-matched 5.14.0-70.140.1.el9_0, kernel-debug-devel-matched 5.14.0-70.140.1.el9_0, kernel-debuginfo-common-s390x 5.14.0-70.140.1.el9_0, kernel-zfcpdump-devel-matched 5.14.0-70.140.1.el9_0, kernel-debuginfo-common-x86_64 5.14.0-70.140.1.el9_0, +2 more
    fixed: vendor fix RHSA-2025:12526
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.128.1.el9_2, rtla 5.14.0-284.128.1.el9_2, kernel-devel-matched 5.14.0-284.128.1.el9_2, kernel-64k-devel-matched 5.14.0-284.128.1.el9_2, kernel-debug-devel-matched 5.14.0-284.128.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.128.1.el9_2, +5 more
    fixed: vendor fix RHSA-2025:12209
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.81.1.el9_4, perf 5.14.0-427.81.1.el9_4, rtla 5.14.0-427.81.1.el9_4, kernel-devel-matched 5.14.0-427.81.1.el9_4, kernel-64k-devel-matched 5.14.0-427.81.1.el9_4, kernel-debug-devel-matched 5.14.0-427.81.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:13135
show 18 more
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-570.30.1.el9_6, kernel-64k 5.14.0-570.30.1.el9_6, kernel-core 5.14.0-570.30.1.el9_6, kernel-tools 5.14.0-570.30.1.el9_6, kernel-modules 5.14.0-570.30.1.el9_6, kernel-64k-core 5.14.0-570.30.1.el9_6, +27 more
    fixed: vendor fix RHSA-2025:11861
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-55.22.1.el10_0, kernel-64k 6.12.0-55.22.1.el10_0, kernel-core 6.12.0-55.22.1.el10_0, kernel-tools 6.12.0-55.22.1.el10_0, kernel-modules 6.12.0-55.22.1.el10_0, kernel-64k-core 6.12.0-55.22.1.el10_0, +27 more
    fixed: vendor fix RHSA-2025:11428
  • Red Hat Enterprise Linux BaseOS E4S (v.9.0) kernel 5.14.0-70.140.1.el9_0, bpftool 5.14.0-70.140.1.el9_0, kernel-core 5.14.0-70.140.1.el9_0, kernel-tools 5.14.0-70.140.1.el9_0, python3-perf 5.14.0-70.140.1.el9_0, kernel-modules 5.14.0-70.140.1.el9_0, +14 more
    fixed: vendor fix RHSA-2025:12526
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.128.1.el9_2, kernel 5.14.0-284.128.1.el9_2, kernel-64k 5.14.0-284.128.1.el9_2, kernel-core 5.14.0-284.128.1.el9_2, kernel-tools 5.14.0-284.128.1.el9_2, python3-perf 5.14.0-284.128.1.el9_2, +28 more
    fixed: vendor fix RHSA-2025:12209
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.81.1.el9_4, kernel 5.14.0-427.81.1.el9_4, kernel-64k 5.14.0-427.81.1.el9_4, kernel-core 5.14.0-427.81.1.el9_4, kernel-tools 5.14.0-427.81.1.el9_4, python3-perf 5.14.0-427.81.1.el9_4, +28 more
    fixed: vendor fix RHSA-2025:13135
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-570.30.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.30.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.30.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.30.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.30.1.el9_6
    fixed: vendor fix RHSA-2025:11861
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-55.22.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.22.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.22.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.22.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.22.1.el10_0
    fixed: vendor fix RHSA-2025:11428
  • Red Hat Enterprise Linux NFV E4S (v.9.0) kernel-rt 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-kvm 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-core 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-modules 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-kvm 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-core 5.14.0-70.140.1.rt21.212.el9_0, +4 more
    fixed: vendor fix RHSA-2025:12525
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-570.30.1.el9_6, kernel-rt-64k 5.14.0-570.30.1.el9_6, kernel-rt-core 5.14.0-570.30.1.el9_6, kernel-rt-modules 5.14.0-570.30.1.el9_6, kernel-rt-64k-core 5.14.0-570.30.1.el9_6, kernel-rt-debug-core 5.14.0-570.30.1.el9_6, +14 more
    fixed: vendor fix RHSA-2025:11861
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-55.22.1.el10_0, kernel-rt-64k 6.12.0-55.22.1.el10_0, kernel-rt-core 6.12.0-55.22.1.el10_0, kernel-rt-modules 6.12.0-55.22.1.el10_0, kernel-rt-64k-core 6.12.0-55.22.1.el10_0, kernel-rt-debug-core 6.12.0-55.22.1.el10_0, +14 more
    fixed: vendor fix RHSA-2025:11428
  • Red Hat Enterprise Linux Real Time E4S (v.9.0) kernel-rt 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-core 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-modules 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-core 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-debug-modules 5.14.0-70.140.1.rt21.212.el9_0, kernel-rt-modules-extra 5.14.0-70.140.1.rt21.212.el9_0, +2 more
    fixed: vendor fix RHSA-2025:12525
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-core 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-modules 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-debug-core 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-modules-core 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-debug-modules 5.14.0-284.128.1.rt14.413.el9_2, +4 more
    fixed: vendor fix RHSA-2025:12311
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.81.1.el9_4, kernel-rt-core 5.14.0-427.81.1.el9_4, kernel-rt-modules 5.14.0-427.81.1.el9_4, kernel-rt-debug-core 5.14.0-427.81.1.el9_4, kernel-rt-modules-core 5.14.0-427.81.1.el9_4, kernel-rt-debug-modules 5.14.0-427.81.1.el9_4, +4 more
    fixed: vendor fix RHSA-2025:13135
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-570.30.1.el9_6, kernel-rt-kvm 5.14.0-570.30.1.el9_6, kernel-rt-core 5.14.0-570.30.1.el9_6, kernel-rt-modules 5.14.0-570.30.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.30.1.el9_6, kernel-rt-debug-core 5.14.0-570.30.1.el9_6, +6 more
    fixed: vendor fix RHSA-2025:11861
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-55.22.1.el10_0, kernel-rt-kvm 6.12.0-55.22.1.el10_0, kernel-rt-core 6.12.0-55.22.1.el10_0, kernel-rt-modules 6.12.0-55.22.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.22.1.el10_0, kernel-rt-debug-core 6.12.0-55.22.1.el10_0, +6 more
    fixed: vendor fix RHSA-2025:11428
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-kvm 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-core 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-modules 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-debug-kvm 5.14.0-284.128.1.rt14.413.el9_2, kernel-rt-debug-core 5.14.0-284.128.1.rt14.413.el9_2, +6 more
    fixed: vendor fix RHSA-2025:12311
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.81.1.el9_4, kernel-rt-kvm 5.14.0-427.81.1.el9_4, kernel-rt-core 5.14.0-427.81.1.el9_4, kernel-rt-modules 5.14.0-427.81.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.81.1.el9_4, kernel-rt-debug-core 5.14.0-427.81.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:13135
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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 SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 d ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

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.