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Fencer Vulns
high 7.8

CVE-2025-38477 json

net/sched: sch_qfq: Fix race condition on qfq_aggregate

published 2025-07-28 15 mo ago modified 2026-10-15 25 d ago also EUVD-2025-22885

cvss
7.8
version 3.1, CNA
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

Summary

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.

Patch / fix

  • Linux Linux 5.4.297, 5.10.241, 5.15.190, 6.1.147, 6.6.100, 6.12.40, 6.15.8, 6.16
  • linux Debian 12 6.1.147-1
  • linux Debian 13 6.12.41-1
  • linux Debian 14 6.16.3-1

debian advisories DEBIAN-CVE-2025-38477

  • linux Ubuntu 22.04 LTS 5.15.0-157.167
  • linux Ubuntu 24.04 LTS 6.8.0-85.85
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1093.100
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1040.42
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1093.102
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1041.43
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1090.96
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1037.41

ubuntu advisories UBUNTU-CVE-2025-38477

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 4.18.0-553.72.1.el8_10
  • perf RHEL 8 4.18.0-553.72.1.el8_10
  • bpftool RHEL 8 4.18.0-553.72.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.72.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.72.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.72.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.72.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.72.1.el8_10

red hat advisories RHSA-2025:22752RHSA-2025:21667RHSA-2025:17161RHSA-2025:17124RHSA-2025:17109RHSA-2025:17009

  • 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-2025:21074-1SUSE-SU-2025:21139-1SUSE-SU-2026:20560-1SUSE-SU-2025:21179-1SUSE-SU-2025:4123-1SUSE-SU-2025:03578-1

  • 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 4.18.0-553.72.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.72.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.72.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.72.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.72.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.72.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.72.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.72.1.el8_10

almalinux advisories ALSA-2025:15008

  • kernel Rocky Linux 8 4.18.0-553.72.1.el8_10

rocky linux advisories RLSA-2025:15008

  • kernel Azure Linux 3.0 6.6.104.2-1
  • kernel CBL-Mariner 2.0 5.15.200.1-1

azure linux advisories AZL-65907AZL-73046

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-2025-38477 updated cvss 4.7

kernel: net/sched: sch_qfq: Fix race condition on qfq_aggregate

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • Red Hat Enterprise Linux 8 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +6 more
    affected: workaround, no fix available “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix available, no fix planned “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.72.1.el8_10, kernel 4.18.0-553.72.1.el8_10, bpftool 4.18.0-553.72.1.el8_10, kernel-core 4.18.0-553.72.1.el8_10, kernel-tools 4.18.0-553.72.1.el8_10, python3-perf 4.18.0-553.72.1.el8_10, +15 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:15008
  • Red Hat Enterprise Linux BaseOS AUS (v. 8.2) perf 4.18.0-193.173.1.el8_2, kernel 4.18.0-193.173.1.el8_2, bpftool 4.18.0-193.173.1.el8_2, kernel-core 4.18.0-193.173.1.el8_2, kernel-tools 4.18.0-193.173.1.el8_2, python3-perf 4.18.0-193.173.1.el8_2, +8 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:21667
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.179.1.el8_4, kernel 4.18.0-305.179.1.el8_4, bpftool 4.18.0-305.179.1.el8_4, kernel-core 4.18.0-305.179.1.el8_4, kernel-tools 4.18.0-305.179.1.el8_4, python3-perf 4.18.0-305.179.1.el8_4, +8 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:22752
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.162.1.el8_6, kernel 4.18.0-372.162.1.el8_6, bpftool 4.18.0-372.162.1.el8_6, kernel-core 4.18.0-372.162.1.el8_6, kernel-tools 4.18.0-372.162.1.el8_6, python3-perf 4.18.0-372.162.1.el8_6, +8 more Red Hat Enterprise Linux BaseOS E4S (v.8.6) perf 4.18.0-372.162.1.el8_6, kernel 4.18.0-372.162.1.el8_6, bpftool 4.18.0-372.162.1.el8_6, kernel-core 4.18.0-372.162.1.el8_6, kernel-tools 4.18.0-372.162.1.el8_6, python3-perf 4.18.0-372.162.1.el8_6, +15 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:17124
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.112.1.el8_8, kernel 4.18.0-477.112.1.el8_8, bpftool 4.18.0-477.112.1.el8_8, kernel-core 4.18.0-477.112.1.el8_8, kernel-tools 4.18.0-477.112.1.el8_8, python3-perf 4.18.0-477.112.1.el8_8, +9 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:17009
show 7 more
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.179.1.el8_4, kernel 4.18.0-305.179.1.el8_4, bpftool 4.18.0-305.179.1.el8_4, kernel-core 4.18.0-305.179.1.el8_4, kernel-tools 4.18.0-305.179.1.el8_4, python3-perf 4.18.0-305.179.1.el8_4, +8 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:22752
  • Red Hat Enterprise Linux BaseOS TUS (v.8.6) perf 4.18.0-372.162.1.el8_6, kernel 4.18.0-372.162.1.el8_6, bpftool 4.18.0-372.162.1.el8_6, kernel-core 4.18.0-372.162.1.el8_6, kernel-tools 4.18.0-372.162.1.el8_6, python3-perf 4.18.0-372.162.1.el8_6, +8 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:17124
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.112.1.el8_8, kernel 4.18.0-477.112.1.el8_8, bpftool 4.18.0-477.112.1.el8_8, kernel-core 4.18.0-477.112.1.el8_8, kernel-tools 4.18.0-477.112.1.el8_8, python3-perf 4.18.0-477.112.1.el8_8, +8 more
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:17009
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.72.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.72.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.72.1.el8_10
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:15008
  • Red Hat Enterprise Linux for Real Time (v. 7 ELS) kernel-rt 3.10.0-1160.140.1.rt56.1292.el7, kernel-rt-trace 3.10.0-1160.140.1.rt56.1292.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.140.1.rt56.1292.el7
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:17109
  • Red Hat Enterprise Linux Server (v. 7 ELS) perf 3.10.0-1160.141.1.el7, kernel 3.10.0-1160.141.1.el7, bpftool 3.10.0-1160.141.1.el7, python-perf 3.10.0-1160.141.1.el7, kernel-kdump 3.10.0-1160.141.1.el7, kernel-tools 3.10.0-1160.141.1.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7 ELS) kernel-debuginfo-common-ppc64 3.10.0-1160.141.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.141.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.141.1.el7
    fixed: vendor fix “To mitigate this issue, prevent module sch_qfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2025:17161
  • Red Hat Enterprise Linux 10 kernel
    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-25-162-05 updated cvss 4.7

Siemens SIMATIC S7-1500 CPU family

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.5
    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 SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

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
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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 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

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.