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Fencer Vulns
high 7.1

CVE-2025-39902 json

mm/slub: avoid accessing metadata when pointer is invalid in object_err()

published 2025-10-01 13 mo ago modified 2026-10-19 20 d ago also EUVD-2025-32902

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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

mm/slub: avoid accessing metadata when pointer is invalid in object_err()

object_err() reports details of an object for further debugging, such as the freelist pointer, redzone, etc. However, if the pointer is invalid, attempting to access object metadata can lead to a crash since it does not point to a valid object.

One known path to the crash is when alloc_consistency_checks() determines the pointer to the allocated object is invalid because of a freelist corruption, and calls object_err() to report it. The debug code should report and handle the corruption gracefully and not crash in the process.

In case the pointer is NULL or check_valid_pointer() returns false for the pointer, only print the pointer value and skip accessing metadata.

Patch / fix

  • Linux Linux 5.4.299, 5.10.243, 5.15.192, 6.1.151, 6.6.105, 6.12.46, 6.16.6, 6.17
  • linux Debian 12 6.1.153-1
  • linux Debian 13 6.12.48-1
  • linux Debian 14 6.16.6-1

debian advisories DEBIAN-CVE-2025-39902

  • linux Ubuntu 22.04 LTS 5.15.0-163.173
  • linux Ubuntu 24.04 LTS 6.8.0-106.106
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1097.104
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1050.53
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1097.106
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1052.55
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1093.99
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1048.53

ubuntu advisories UBUNTU-CVE-2025-39902

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 8 4.18.0-553.156.1.el8_10
  • perf RHEL 8 4.18.0-553.156.1.el8_10
  • bpftool RHEL 8 4.18.0-553.156.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.156.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.156.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.156.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.156.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.156.1.el8_10

red hat advisories RHSA-2026:55764RHSA-2026:55765

  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-38.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-38.1
  • 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

suse advisories SUSE-SU-2025:4301-1SUSE-SU-2025:21052-1SUSE-SU-2025:21064-1SUSE-SU-2025:21074-1SUSE-SU-2025:21139-1SUSE-SU-2026:20560-1

  • 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 AlmaLinux 8 4.18.0-553.156.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.156.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.156.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.156.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.156.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.156.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.156.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.156.1.el8_10

almalinux advisories ALSA-2026:55764ALSA-2026:55765

  • kernel-rt Rocky Linux 8 4.18.0-553.156.1.rt7.497.el8_10
  • kernel Rocky Linux 8 4.18.0-553.156.1.el8_10

rocky linux advisories RLSA-2026:55765RLSA-2026:55764

  • kernel Azure Linux 3.0 6.6.112.1-1

azure linux advisories AZL-68019

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-2025-39902 updated cvss 5.8

kernel: mm/slub: avoid accessing metadata when pointer is invalid in object_err()

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.156.1.el8_10, kernel 4.18.0-553.156.1.el8_10, bpftool 4.18.0-553.156.1.el8_10, kernel-core 4.18.0-553.156.1.el8_10, kernel-tools 4.18.0-553.156.1.el8_10, python3-perf 4.18.0-553.156.1.el8_10, +15 more Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.156.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.156.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.156.1.el8_10
    fixed: vendor fix RHSA-2026:55764
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-kvm 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-core 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-modules 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-debug-kvm 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-debug-core 4.18.0-553.156.1.rt7.497.el8_10, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-core 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-modules 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-debug-core 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-debug-modules 4.18.0-553.156.1.rt7.497.el8_10, kernel-rt-modules-extra 4.18.0-553.156.1.rt7.497.el8_10, +2 more
    fixed: vendor fix RHSA-2026:55765
  • 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
24 d ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
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.