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Fencer Vulns
high 7.8

CVE-2025-38177 json

sch_hfsc: make hfsc_qlen_notify() idempotent

published 2025-07-04 16 mo ago modified 2026-08-05 3 mo ago also EUVD-2025-20019

cvss
7.8
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 12%
public exploits
0
none known

Summary

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

sch_hfsc: make hfsc_qlen_notify() idempotent

hfsc_qlen_notify() is not idempotent either and not friendly to its callers, like fq_codel_dequeue(). Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers' life:

1. update_vf() decreases cl->cl_nactive, so we can check whether it is non-zero before calling it.

2. eltree_remove() always removes RB node cl->el_node, but we can use RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.

Patch / fix

  • Linux Linux 5.4.297, 5.10.241, 5.15.190, 6.1.138, 6.6.90, 6.12.28, 6.14.6, 6.15
  • linux Debian 12 6.1.139-1
  • linux Debian 14, Debian 13 6.12.29-1

debian advisories DEBIAN-CVE-2025-38177

  • linux Ubuntu 22.04 LTS 5.15.0-143.153
  • linux Ubuntu 24.04 LTS 6.8.0-63.66
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1087.94
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1031.33
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1086.95
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1032.34
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1084.90
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1027.31

ubuntu advisories UBUNTU-CVE-2025-38177

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 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4
  • perf RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4
  • bpftool RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4
  • kernel-core RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4
  • kernel-tools RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4
  • python3-perf RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4
  • kernel-modules RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4
  • kernel-debug-core RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 4.18.0-305.170.1.el8_4

red hat advisories RHSA-2025:15035RHSA-2025:15016RHSA-2025:14746RHSA-2025:14748RHSA-2025:14744RHSA-2025:14696

  • 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-2026:0688-1SUSE-SU-2025:21074-1SUSE-SU-2025:21139-1SUSE-SU-2026:20560-1SUSE-SU-2025:21179-1SUSE-SU-2025:4123-1

  • 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 CBL-Mariner 2.0 5.15.200.1-1

azure linux advisories AZL-72763

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-2025-38177 updated cvss 7.0

kernel: sch_hfsc: make hfsc_qlen_notify() idempotent

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.85.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.85.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.85.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.85.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.85.1.el9_4
    fixed: vendor fix RHSA-2025:15016
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) perf 5.14.0-70.144.1.el9_0, kernel-devel-matched 5.14.0-70.144.1.el9_0, kernel-debug-devel-matched 5.14.0-70.144.1.el9_0, kernel-debuginfo-common-s390x 5.14.0-70.144.1.el9_0, kernel-zfcpdump-devel-matched 5.14.0-70.144.1.el9_0, kernel-debuginfo-common-x86_64 5.14.0-70.144.1.el9_0, +2 more
    fixed: vendor fix RHSA-2025:14744
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.134.1.el9_2, rtla 5.14.0-284.134.1.el9_2, kernel-devel-matched 5.14.0-284.134.1.el9_2, kernel-64k-devel-matched 5.14.0-284.134.1.el9_2, kernel-debug-devel-matched 5.14.0-284.134.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.134.1.el9_2, +5 more
    fixed: vendor fix RHSA-2025:14696
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.85.1.el9_4, perf 5.14.0-427.85.1.el9_4, rtla 5.14.0-427.85.1.el9_4, kernel-devel-matched 5.14.0-427.85.1.el9_4, kernel-64k-devel-matched 5.14.0-427.85.1.el9_4, kernel-debug-devel-matched 5.14.0-427.85.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:15016
  • Red Hat Enterprise Linux BaseOS AUS (v. 8.2) perf 4.18.0-193.165.1.el8_2, kernel 4.18.0-193.165.1.el8_2, bpftool 4.18.0-193.165.1.el8_2, kernel-core 4.18.0-193.165.1.el8_2, kernel-tools 4.18.0-193.165.1.el8_2, python3-perf 4.18.0-193.165.1.el8_2, +8 more
    fixed: vendor fix RHSA-2025:14742
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.170.1.el8_4, kernel 4.18.0-305.170.1.el8_4, bpftool 4.18.0-305.170.1.el8_4, kernel-core 4.18.0-305.170.1.el8_4, kernel-tools 4.18.0-305.170.1.el8_4, python3-perf 4.18.0-305.170.1.el8_4, +8 more
    fixed: vendor fix RHSA-2025:15035
show 17 more
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.158.1.el8_6, kernel 4.18.0-372.158.1.el8_6, bpftool 4.18.0-372.158.1.el8_6, kernel-core 4.18.0-372.158.1.el8_6, kernel-tools 4.18.0-372.158.1.el8_6, python3-perf 4.18.0-372.158.1.el8_6, +8 more Red Hat Enterprise Linux BaseOS E4S (v.8.6) perf 4.18.0-372.158.1.el8_6, kernel 4.18.0-372.158.1.el8_6, bpftool 4.18.0-372.158.1.el8_6, kernel-core 4.18.0-372.158.1.el8_6, kernel-tools 4.18.0-372.158.1.el8_6, python3-perf 4.18.0-372.158.1.el8_6, +15 more
    fixed: vendor fix RHSA-2025:14692
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.107.1.el8_8, kernel 4.18.0-477.107.1.el8_8, bpftool 4.18.0-477.107.1.el8_8, kernel-core 4.18.0-477.107.1.el8_8, kernel-tools 4.18.0-477.107.1.el8_8, python3-perf 4.18.0-477.107.1.el8_8, +9 more
    fixed: vendor fix RHSA-2025:14511
  • Red Hat Enterprise Linux BaseOS E4S (v.9.0) kernel 5.14.0-70.144.1.el9_0, bpftool 5.14.0-70.144.1.el9_0, kernel-core 5.14.0-70.144.1.el9_0, kernel-tools 5.14.0-70.144.1.el9_0, python3-perf 5.14.0-70.144.1.el9_0, kernel-modules 5.14.0-70.144.1.el9_0, +14 more
    fixed: vendor fix RHSA-2025:14744
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.134.1.el9_2, kernel 5.14.0-284.134.1.el9_2, kernel-64k 5.14.0-284.134.1.el9_2, kernel-core 5.14.0-284.134.1.el9_2, kernel-tools 5.14.0-284.134.1.el9_2, python3-perf 5.14.0-284.134.1.el9_2, +28 more
    fixed: vendor fix RHSA-2025:14696
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.85.1.el9_4, kernel 5.14.0-427.85.1.el9_4, kernel-64k 5.14.0-427.85.1.el9_4, kernel-core 5.14.0-427.85.1.el9_4, kernel-tools 5.14.0-427.85.1.el9_4, python3-perf 5.14.0-427.85.1.el9_4, +28 more
    fixed: vendor fix RHSA-2025:15016
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.170.1.el8_4, kernel 4.18.0-305.170.1.el8_4, bpftool 4.18.0-305.170.1.el8_4, kernel-core 4.18.0-305.170.1.el8_4, kernel-tools 4.18.0-305.170.1.el8_4, python3-perf 4.18.0-305.170.1.el8_4, +8 more
    fixed: vendor fix RHSA-2025:15035
  • Red Hat Enterprise Linux BaseOS TUS (v.8.6) perf 4.18.0-372.158.1.el8_6, kernel 4.18.0-372.158.1.el8_6, bpftool 4.18.0-372.158.1.el8_6, kernel-core 4.18.0-372.158.1.el8_6, kernel-tools 4.18.0-372.158.1.el8_6, python3-perf 4.18.0-372.158.1.el8_6, +8 more
    fixed: vendor fix RHSA-2025:14692
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.107.1.el8_8, kernel 4.18.0-477.107.1.el8_8, bpftool 4.18.0-477.107.1.el8_8, kernel-core 4.18.0-477.107.1.el8_8, kernel-tools 4.18.0-477.107.1.el8_8, python3-perf 4.18.0-477.107.1.el8_8, +8 more
    fixed: vendor fix RHSA-2025:14511
  • Red Hat Enterprise Linux for Real Time (v. 7 ELS) kernel-rt 3.10.0-1160.137.1.rt56.1289.el7, kernel-rt-trace 3.10.0-1160.137.1.rt56.1289.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.137.1.rt56.1289.el7
    fixed: vendor fix RHSA-2025:14746
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-core 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-modules 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-debug-core 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-modules-core 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-debug-modules 5.14.0-284.134.1.rt14.419.el9_2, +4 more
    fixed: vendor fix RHSA-2025:14691
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.85.1.el9_4, kernel-rt-core 5.14.0-427.85.1.el9_4, kernel-rt-modules 5.14.0-427.85.1.el9_4, kernel-rt-debug-core 5.14.0-427.85.1.el9_4, kernel-rt-modules-core 5.14.0-427.85.1.el9_4, kernel-rt-debug-modules 5.14.0-427.85.1.el9_4, +4 more
    fixed: vendor fix RHSA-2025:15016
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-kvm 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-core 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-modules 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-debug-kvm 5.14.0-284.134.1.rt14.419.el9_2, kernel-rt-debug-core 5.14.0-284.134.1.rt14.419.el9_2, +6 more
    fixed: vendor fix RHSA-2025:14691
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.85.1.el9_4, kernel-rt-kvm 5.14.0-427.85.1.el9_4, kernel-rt-core 5.14.0-427.85.1.el9_4, kernel-rt-modules 5.14.0-427.85.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.85.1.el9_4, kernel-rt-debug-core 5.14.0-427.85.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:15016
  • Red Hat Enterprise Linux Server (v. 7 ELS) perf 3.10.0-1160.137.1.el7, kernel 3.10.0-1160.137.1.el7, bpftool 3.10.0-1160.137.1.el7, python-perf 3.10.0-1160.137.1.el7, kernel-kdump 3.10.0-1160.137.1.el7, kernel-tools 3.10.0-1160.137.1.el7, +7 more
    fixed: vendor fix RHSA-2025:14748
  • Red Hat Enterprise Linux Server AUS (v. 7.7) perf 3.10.0-1062.99.1.el7, kernel 3.10.0-1062.99.1.el7, bpftool 3.10.0-1062.99.1.el7, python-perf 3.10.0-1062.99.1.el7, kernel-tools 3.10.0-1062.99.1.el7, kernel-tools-libs 3.10.0-1062.99.1.el7, +2 more
    fixed: vendor fix RHSA-2025:14413
  • Red Hat Enterprise Linux Server Optional (v. 7 ELS) kernel-debuginfo-common-ppc64 3.10.0-1160.137.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.137.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.137.1.el7
    fixed: vendor fix RHSA-2025:14748
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.99.1.el7
    fixed: vendor fix RHSA-2025:14413

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
4 mo ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% 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 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.