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OpenAdvisories
High · 7.5 CVE-2021-47109 EUVD-2021-33757GHSA-4jvh-cf85-8374

neighbour: allow NUD_NOARP entries to be forced GCed

Published Mar 15, 2024 · Updated Aug 5, 2026 · Assigned by Linux

Vendor: Linux Product: Linux 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-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.2 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.2 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 Package: linux-azure-fips Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.2 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-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.2 Package: linux-hwe-edge Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-kvm Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.2 Package: linux-nvidia-6.2 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-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-vmware Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

neighbour: allow NUD_NOARP entries to be forced GCed

IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6. It's possible to
fill up the neighbour table with enough entries that it will overflow for
valid connections after that.

This behaviour is more prevalent after commit 58956317c8de ("neighbor:
Improve garbage collection") is applied, as it prevents removal from
entries that are not NUD_FAILED, unless they are more than 5s old.

Affected products

VendorProductAffectedFixed
Linux Linux 5.0 5.4.125

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 5.10.46-1 —
Debian 13 linux 5.10.46-1 —
Debian 12 linux 5.10.46-1 —
ReleasePackageFixed inAdvisory
Ubuntu 24.04 LTS linux-raspi-realtime No fix yet —
Ubuntu 22.04 LTS linux-riscv +22 No fix yet —
Ubuntu 20.04 LTS linux 5.4.0-81.91 —
Ubuntu 20.04 LTS linux-aws 5.4.0-1055.58 —
Ubuntu 20.04 LTS linux-azure 5.4.0-1056.58 —
Ubuntu 20.04 LTS linux-bluefield 5.4.0-1019.22 —
Ubuntu 20.04 LTS linux-gcp 5.4.0-1051.55 —
Ubuntu 20.04 LTS linux-gke +26 No fix yet —
Ubuntu 20.04 LTS linux-gkeop 5.4.0-1022.23 —
Ubuntu 20.04 LTS linux-kvm 5.4.0-1045.47 —
Ubuntu 20.04 LTS linux-oracle 5.4.0-1053.57 —
Ubuntu 20.04 LTS linux-raspi 5.4.0-1042.46 —
Ubuntu 18.04 LTS linux-aws-5.4 5.4.0-1055.58~18.04.1 —
Ubuntu 18.04 LTS linux-azure-5.4 5.4.0-1056.58~18.04.1 —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 18.04 LTS linux-gcp-5.4 5.4.0-1051.55~18.04.1 —
Ubuntu 18.04 LTS linux-hwe-5.4 5.4.0-81.91~18.04.1 —
Ubuntu 18.04 LTS linux-oracle-5.4 5.4.0-1053.57~18.04.1 —
Ubuntu 18.04 LTS linux-raspi-5.4 5.4.0-1042.46~18.04.3 —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 20.04 LTS linux-aws-fips 5.4.0-1069.73+fips2 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-azure-fips 5.4.0-1073.76+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips 5.4.0-1032.37 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-gcp-fips 5.4.0-1067.71~20.04.1 —
ReleasePackageFixed inAdvisory
SLES 15 SP3 kernel-64kb +7 5.3.18-150300.59.158.1 SUSE-SU-2024:1489-1
SLES 15 SP3 kernel-default-base 5.3.18-150300.59.158.1.150300.18.92.5 SUSE-SU-2024:1489-1
SLES 15 SP2 kernel-default-base 5.3.18-150200.24.188.1.150200.9.95.3 SUSE-SU-2024:1454-1
SLES 15 SP2 kernel-docs +5 5.3.18-150200.24.188.1 SUSE-SU-2024:1454-1
Show 9 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 15 SP3 kernel-default-base 5.3.18-150300.59.158.1.150300.18.92.5 SUSE-SU-2024:1489-1
SLES for SAP 15 SP3 kernel-docs +5 5.3.18-150300.59.158.1 SUSE-SU-2024:1489-1
SLES for SAP 15 SP2 kernel-default-base 5.3.18-150200.24.188.1.150200.9.95.3 SUSE-SU-2024:1454-1
SLES for SAP 15 SP2 kernel-docs +5 5.3.18-150200.24.188.1 SUSE-SU-2024:1454-1
SLE Micro 5.2 kernel-default 5.3.18-150300.59.158.1 SUSE-SU-2024:1489-1
SLE Micro 5.2 kernel-default-base 5.3.18-150300.59.158.1.150300.18.92.5 SUSE-SU-2024:1489-1
SLE Micro 5.2 kernel-rt +1 5.3.18-150300.166.1 SUSE-SU-2024:1465-1
SLE Micro 5.1 kernel-default 5.3.18-150300.59.158.1 SUSE-SU-2024:1489-1
SLE Micro 5.1 kernel-default-base 5.3.18-150300.59.158.1.150300.18.92.5 SUSE-SU-2024:1489-1
SLE Micro 5.1 kernel-rt +1 5.3.18-150300.166.1 SUSE-SU-2024:1465-1
SLE Live Patching 15 SP3 kernel-default 5.3.18-150300.59.158.1 SUSE-SU-2024:1489-1
SLE Live Patching 15 SP3 kernel-livepatch-SLE15-SP3_Update_43 1-150300.7.3.5 SUSE-SU-2024:1489-1
SLE Live Patching 15 SP2 kernel-default 5.3.18-150200.24.188.1 SUSE-SU-2024:1454-1
SLE Live Patching 15 SP2 kernel-livepatch-SLE15-SP2_Update_47 1-150200.5.3.3 SUSE-SU-2024:1454-1
SLE HPC 15 SP3 kernel-64kb +6 5.3.18-150300.59.158.1 SUSE-SU-2024:1489-1
SLE HPC 15 SP3 kernel-default-base 5.3.18-150300.59.158.1.150300.18.92.5 SUSE-SU-2024:1489-1
SLE HPC 15 SP2 kernel-default-base 5.3.18-150200.24.188.1.150200.9.95.3 SUSE-SU-2024:1454-1
SLE HPC 15 SP2 kernel-docs +5 5.3.18-150200.24.188.1 SUSE-SU-2024:1454-1
SUSE Enterprise Storage 7.1 kernel-64kb +6 5.3.18-150300.59.158.1 SUSE-SU-2024:1489-1
SUSE Enterprise Storage 7.1 kernel-default-base 5.3.18-150300.59.158.1.150300.18.92.5 SUSE-SU-2024:1489-1

Advisories 4

References