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High · 7.8 CVE-2026-23351 EUVD-2026-15323GHSA-42q3-4jmh-pwqx

netfilter: nft_set_pipapo: split gc into unlink and reclaim phase

Published Mar 25, 2026 · Updated Nov 10, 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-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure 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-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 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-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-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 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-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 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-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 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-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 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-6.17 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-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 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-6.17 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:

netfilter: nft_set_pipapo: split gc into unlink and reclaim phase

Yiming Qian reports Use-after-free in the pipapo set type:
Under a large number of expired elements, commit-time GC can run for a very
long time in a non-preemptible context, triggering soft lockup warnings and
RCU stall reports (local denial of service).

We must split GC in an unlink and a reclaim phase.

We cannot queue elements for freeing until pointers have been swapped.
Expired elements are still exposed to both the packet path and userspace
dumpers via the live copy of the data structure.

call_rcu() does not protect us: dump operations or element lookups starting
after call_rcu has fired can still observe the free'd element, unless the
commit phase has made enough progress to swap the clone and live pointers
before any new reader has picked up the old version.

This a similar approach as done recently for the rbtree backend in commit
35f83a75529a ("netfilter: nft_set_rbtree: don't gc elements on insert").

Affected products

VendorProductAffectedFixed
Linux Linux 5.6 5.10.253

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 6.19.8-1 —
Debian 13 linux 6.12.85-1 —
Debian 12 linux 6.1.170-1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1022.26 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1092.94 —
Ubuntu 25.10 linux 6.17.0-29.29 USN-8277-1
Ubuntu 25.10 linux-aws +1 6.17.0-1015.15 USN-8310-1, USN-8277-1
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.10 linux-gcp 6.17.0-1018.19 USN-8374-1
Ubuntu 25.10 linux-oracle 6.17.0-1014.14 USN-8277-1
Ubuntu 25.10 linux-raspi 6.17.0-1017.17 USN-8277-1
Ubuntu 25.10 linux-realtime 6.17.0-1013.15 USN-8277-1
Ubuntu 25.10 linux-riscv 6.17.0-29.29.1 —
Ubuntu 24.04 LTS linux 6.8.0-117.117 USN-8278-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1055.58 USN-8278-1
Ubuntu 24.04 LTS linux-aws-6.17 6.17.0-1017.17~24.04.1 USN-8374-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1056.62 USN-8278-2
Ubuntu 24.04 LTS linux-azure-6.17 6.17.0-1015.15~24.04.1 USN-8310-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1058.65 —
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1039.42 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1058.61 USN-8278-1
Ubuntu 24.04 LTS linux-gcp-6.17 6.17.0-1018.19~24.04.1 USN-8374-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1054.60 USN-8278-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1041.44 USN-8278-1
Ubuntu 24.04 LTS linux-hwe-6.17 6.17.0-29.29~24.04.1 USN-8277-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1055.56 USN-8278-1
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-117.117.1 USN-8278-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1054.57 USN-8289-1
Ubuntu 24.04 LTS linux-nvidia-6.17 6.17.0-1026.26 USN-8508-1
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1054.57.1 USN-8289-1
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1024.24 USN-8296-2
Ubuntu 24.04 LTS linux-oem-6.17 6.17.0-1023.23 USN-8277-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1054.55 —
Ubuntu 24.04 LTS linux-oracle-6.17 6.17.0-1014.14~24.04.1 USN-8277-2
Ubuntu 24.04 LTS linux-raspi 6.8.0-1056.60 USN-8278-1
Ubuntu 24.04 LTS linux-riscv +18 No fix yet —
Ubuntu 24.04 LTS linux-riscv-6.17 6.17.0-29.29.1~24.04.1 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1032.33 USN-8499-1
Ubuntu 22.04 LTS linux 5.15.0-179.189 USN-8279-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1108.115 USN-8279-1
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1057.60~22.04.1 —
Ubuntu 22.04 LTS linux-azure +1 5.15.0-1114.123 USN-8426-2
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1059.65~22.04.1 USN-8440-1
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1058.65~22.04.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1108.117 USN-8279-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1060.63~22.04.1 —
Ubuntu 22.04 LTS linux-gke 5.15.0-1104.110 USN-8279-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1091.99 USN-8279-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-124.124~22.04.1 —
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1102.105 USN-8279-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1055.56~22.04.1 USN-8278-1
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1103.109 USN-8279-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1100.105 USN-8279-1
Ubuntu 22.04 LTS linux-lowlatency 5.15.0-178.188 USN-8291-3
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-117.117.1~22.04.1 USN-8278-1
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1103.104 USN-8279-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1054.57~22.04.1 USN-8289-2
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1060.60 USN-8279-1
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1049.49 USN-8279-3
Ubuntu 22.04 LTS linux-oracle 5.15.0-1105.111 USN-8279-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1054.55~22.04.1 —
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 6.8.0-117.117~22.04.1 —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1074.78 USN-8528-1
Show 9 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
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 6.8.0-2045.46 USN-8278-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1051.52 USN-8278-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.17 6.17.0-1013.15~24.04.1 USN-8277-1
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1099.101 USN-8291-1
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1107.116 USN-8279-1
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1051.52~22.04.1 USN-8278-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1055.58+fips1 USN-8278-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1059.65+fips1 USN-8393-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-116.116+fips1 USN-8296-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1058.61+fips1 USN-8278-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1108.115+fips1 USN-8279-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1114.123+fips1 USN-8426-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-179.189+fips1 USN-8279-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1108.117+fips1 USN-8279-1
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1108.115~20.04.1 USN-8279-1
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1114.123~20.04.1 USN-8426-1
Ubuntu Pro 20.04 LTS linux-bluefield No fix yet —
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1108.117~20.04.1 USN-8279-2
Ubuntu Pro 20.04 LTS linux-hwe-5.15 5.15.0-179.189~20.04.1 USN-8279-1
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1102.105~20.04.1 USN-8279-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1103.109~20.04.1 USN-8279-1
Ubuntu Pro 20.04 LTS linux-lowlatency-hwe-5.15 5.15.0-178.188~20.04.1 USN-8291-2
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1060.60~20.04.1 USN-8279-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1104.110~20.04.1 USN-8439-1
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1102.106~20.04.1 —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +7 6.4.0-150700.53.55.1 SUSE-SU-2026:2238-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.55.1.150700.17.33.1 SUSE-SU-2026:2238-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.112.1 SUSE-SU-2026:2195-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.112.1.150600.12.52.1 SUSE-SU-2026:2195-1
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 15 SP6 kernel-default-base 6.4.0-150600.23.112.1.150600.12.52.1 SUSE-SU-2026:2195-1
SLES for SAP 15 SP6 kernel-docs +4 6.4.0-150600.23.112.1 SUSE-SU-2026:2195-1
SLE Micro 6.2 kernel-syms +1 6.12.0-160000.33.1 SUSE-SU-2026:21834-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.55.1 SUSE-SU-2026:2238-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_15 1-150700.15.3.1 SUSE-SU-2026:2238-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.112.1 SUSE-SU-2026:2195-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_26 1-150600.13.3.1 SUSE-SU-2026:2195-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.12.77-99.140 +2 1:1.0-0.amzn2023 ALAS2023-2026-1681, ALAS2023-2026-1596, ALAS2023-2026-1543
Amazon Linux 2023 perf +14 1:6.1.168-202.320.amzn2023 ALAS2023-2026-1681
Amazon Linux 2023 perf6.12 +14 1:6.12.77-99.140.amzn2023 ALAS2023-2026-1543
Amazon Linux 2023 perf6.18 +14 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.130.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-204.92.4.2.el10uek ELSA-2026-50372

Advisories 40

References