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Unscored CVE-2025-38457 EUVD-2025-22684GHSA-7hwq-jhp4-6v79

net/sched: Abort __tc_modify_qdisc if parent class does not exist

Published Jul 25, 2025 · Updated Nov 5, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-aws-hwe Package: linux-azure Package: linux-azure-4.15 Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-4.15 Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-ibm-6.8 Package: linux-intel Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-lts-xenial Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

net/sched: Abort __tc_modify_qdisc if parent class does not exist

Lion's patch [1] revealed an ancient bug in the qdisc API.
Whenever a user creates/modifies a qdisc specifying as a parent another
qdisc, the qdisc API will, during grafting, detect that the user is
not trying to attach to a class and reject. However grafting is
performed after qdisc_create (and thus the qdiscs' init callback) is
executed. In qdiscs that eventually call qdisc_tree_reduce_backlog
during init or change (such as fq, hhf, choke, etc), an issue
arises. For example, executing the following commands:

sudo tc qdisc add dev lo root handle a: htb default 2
sudo tc qdisc add dev lo parent a: handle beef fq

Qdiscs such as fq, hhf, choke, etc unconditionally invoke
qdisc_tree_reduce_backlog() in their control path init() or change() which
then causes a failure to find the child class; however, that does not stop
the unconditional invocation of the assumed child qdisc's qlen_notify with
a null class. All these qdiscs make the assumption that class is non-null.

The solution is ensure that qdisc_leaf() which looks up the parent
class, and is invoked prior to qdisc_create(), should return failure on
not finding the class.
In this patch, we leverage qdisc_leaf to return ERR_PTRs whenever the
parentid doesn't correspond to a class, so that we can detect it
earlier on and abort before qdisc_create is called.

[1] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/

Affected products

VendorProductAffectedFixed
Linux Linux 2.6.20 5.4.296

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.16.3-1 —
Debian 13 linux 6.12.41-1 DSA-5975-1
Debian 12 linux 6.1.147-1 DSA-5973-1
Debian 11 linux 5.10.244-1 DLA-4327-1
Debian 11 linux-6.1 6.1.153-1~deb11u1 DLA-4328-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1016.20 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1076.78 —
Ubuntu 26.04 LTS linux-vmware No fix yet —
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 24.04 LTS linux 6.8.0-100.100 USN-8028-1
Ubuntu 24.04 LTS linux-aws +1 6.8.0-1046.49 USN-8028-5
Ubuntu 24.04 LTS linux-aws-6.14 +2 6.14.0-1017.17~24.04.1 USN-7934-1, USN-7879-3
Ubuntu 24.04 LTS linux-azure 6.8.0-1046.52 USN-8074-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1046.53 —
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1039.42 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1047.50 USN-8031-3
Ubuntu 24.04 LTS linux-gcp-6.14 6.14.0-1020.21~24.04.1 USN-7879-4
Ubuntu 24.04 LTS linux-gke 6.8.0-1043.48 USN-8031-3
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1030.33 USN-8028-5
Ubuntu 24.04 LTS linux-hwe-6.14 6.14.0-36.36~24.04.1 USN-7879-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1044.44 USN-8028-8
Ubuntu 24.04 LTS linux-intel +12 No fix yet —
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-100.100.1 USN-8052-1
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1046.49.1 USN-8028-7
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1020.20 —
Ubuntu 24.04 LTS linux-oem-6.14 6.14.0-1016.16 USN-7880-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1043.44 USN-8028-5
Ubuntu 24.04 LTS linux-raspi 6.8.0-1047.51 USN-8028-1
Ubuntu 24.04 LTS linux-riscv-6.14 6.14.0-36.36.1~24.04.1 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1023.24 USN-8052-2
Show 19 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 22.04 LTS linux +1 5.15.0-156.166 USN-7774-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1092.99 USN-7774-1
Ubuntu 22.04 LTS linux-aws-6.8 +1 6.8.0-1046.49~22.04.1 USN-8028-5
Ubuntu 22.04 LTS linux-azure 5.15.0-1096.105 USN-7775-2
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1051.57~22.04.1 USN-8126-1
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1096.105.1 —
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1046.53~22.04.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1092.101 USN-7774-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1047.50~22.04.2 USN-8031-1
Ubuntu 22.04 LTS linux-gke 5.15.0-1089.95 USN-7774-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1075.83 USN-7774-1
Ubuntu 22.04 LTS linux-hwe-6.8 +1 6.8.0-100.100~22.04.1 USN-8028-6
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1086.89 USN-7774-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1044.44~22.04.1 USN-8028-8
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1087.93 USN-7774-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1088.93 USN-7774-4
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-100.100.1~22.04.1 USN-8028-6
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1087.88 USN-7774-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1045.45 USN-7774-1
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1034.34 USN-7774-5
Ubuntu 22.04 LTS linux-oracle 5.15.0-1090.96 USN-7774-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1043.44~22.04.1 USN-8028-5
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1056.60 USN-7774-1
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2037.38 USN-8028-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1041.42 USN-8028-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 6.14.0-1016.16~24.04.1 USN-7879-2
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1085.87 USN-7774-3
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1092.101 USN-7774-3
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1041.42~22.04.1 USN-8028-2
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1046.49+fips1 USN-8028-4
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1046.52+fips1 USN-8074-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-100.100+fips1 USN-8028-4
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1047.50+fips1 USN-8031-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1092.99+fips1 USN-7774-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1096.105+fips1 USN-7775-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-156.166+fips1 USN-7774-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1092.101+fips1 USN-7774-2
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux +10 No fix yet —
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1092.99~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1096.105~20.04.1 USN-7775-3
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1092.101~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-hwe-5.15 +1 5.15.0-156.166~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1086.89~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1087.93~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1045.45~20.04.1 USN-7774-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1090.96~20.04.1 USN-7776-1
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1087.91~20.04.1 —
Ubuntu Pro 18.04 LTS linux +12 No fix yet —
Ubuntu Pro 16.04 LTS linux +7 No fix yet —
Ubuntu Pro 14.04 LTS linux +3 No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +5 6.4.0-150700.53.11.1 SUSE-SU-2025:02997-1
SLES 15 SP7 kernel-azure +2 6.4.0-150700.20.11.1 SUSE-SU-2025:03011-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.11.1.150700.17.9.4 SUSE-SU-2025:02997-1
SLES 15 SP7 kernel-docs 6.4.0-150700.53.11.3 SUSE-SU-2025:02997-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.65.1 SUSE-SU-2025:02996-1
SLES 15 SP6 kernel-azure +2 6.4.0-150600.8.48.1 SUSE-SU-2025:02969-1
SLES 15 SP6 kernel-coco +3 6.4.0-15061.28.coco15sp6.1 SUSE-SU-2025:02923-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.65.1.150600.12.28.4 SUSE-SU-2025:02996-1
SLES 12 SP5 kernel-syms +2 4.12.14-122.272.1 SUSE-SU-2025:03204-1
Show 10 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +7 6.12.0-160000.6.1 SUSE-SU-2025:21139-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.6.1.160000.2.4 SUSE-SU-2025:21139-1
SLES 16.0 kernel-64kb +7 6.12.0-160000.6.1 SUSE-SU-2025:21179-1, SUSE-SU-2025:21139-1
SLES 16.0 kernel-default-base 6.12.0-160000.6.1.160000.2.4 SUSE-SU-2025:21139-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.6.1.160000.2.4 SUSE-SU-2025:21074-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.6.1 SUSE-SU-2026:20560-1, SUSE-SU-2025:21074-1
SLE Micro 6.1 kernel-default-base 6.4.0-32.1.21.10 SUSE-SU-2025:20602-1
SLE Micro 6.1 kernel-rt +1 6.4.0-35.1 SUSE-SU-2025:20601-1
SLE Micro 6.1 kernel-source +2 6.4.0-32.1 SUSE-SU-2025:20602-1
SLE Micro 6.0 kernel-default-base 6.4.0-32.1.21.10 SUSE-SU-2025:20586-1
SLE Micro 6.0 kernel-rt +1 6.4.0-35.1 SUSE-SU-2025:20577-1
SLE Micro 6.0 kernel-source +2 6.4.0-32.1 SUSE-SU-2025:20586-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.11.1 SUSE-SU-2025:02997-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_3 1-150700.1.5.1 SUSE-SU-2025:02853-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_3 1-150700.15.3.4 SUSE-SU-2025:02997-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.65.1 SUSE-SU-2025:02996-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_14 1-150600.1.5.1 SUSE-SU-2025:03023-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_14 1-150600.13.3.4 SUSE-SU-2025:02996-1
SLE Live Patching 12 SP5 kernel-default 4.12.14-122.272.1 SUSE-SU-2025:03204-1
SLE Live Patching 12 SP5 kgraft-patch-SLE12-SP5_Update_72 1-8.3.1 SUSE-SU-2025:03204-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.13.1 SUSE-SU-2025:02853-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.49.1 SUSE-SU-2025:03023-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.6.1.160000.2.4 openSUSE-SU-2025:20081-1
openSUSE Leap 16.0 kernel-rt +10 6.12.0-160000.6.1 openSUSE-SU-2025:20081-1
openSUSE Leap 15.6 dtb-aarch64 +10 6.4.0-150600.23.65.1 SUSE-SU-2025:02996-1
openSUSE Leap 15.6 kernel-azure +2 6.4.0-150600.8.48.1 SUSE-SU-2025:02969-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.65.1.150600.12.28.4 SUSE-SU-2025:02996-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.49.1 SUSE-SU-2025:03023-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.12.40-63.114 +1 1:1.0-0.amzn2023 ALAS2023-2025-1145, ALAS2023-2025-1144
Amazon Linux 2023 perf +14 1:6.1.147-172.266.amzn2023 ALAS2023-2025-1144
Amazon Linux 2023 perf6.12 +14 1:6.12.40-63.114.amzn2023 ALAS2023-2025-1145

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.104.2-1 —
Azure Linux 2 (CBL-Mariner) kernel 5.15.200.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-103.40.4.1.el10uek ELSA-2025-20551
Oracle Linux 8 bpftool +18 5.15.0-313.189.5.1.el9uek ELSA-2025-20716
Oracle Linux 7 kernel-uek +6 5.4.17-2136.348.3.el8uek ELSA-2025-20663
Oracle Linux 7 kernel-uek-tools 5.4.17-2136.348.3.el7uek ELSA-2025-20663

Advisories 50

References