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Unscored CVE-2024-56751 EUVD-2024-53394GHSA-4fc4-p432-gw7h

ipv6: release nexthop on device removal

Published Dec 29, 2024 · 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-6.2 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-5.4 Package: linux-azure-5.8 Package: linux-azure-6.11 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-6.2 Package: linux-azure-fips Package: linux-azure-nvidia 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-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 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-6.2 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-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-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.2 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-6.5 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-6.5 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-6.8 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-6.5 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:

ipv6: release nexthop on device removal

The CI is hitting some aperiodic hangup at device removal time in the
pmtu.sh self-test:

unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 6
ref_tracker: veth_A-R1@ffff888013df15d8 has 1/5 users at
dst_init+0x84/0x4a0
dst_alloc+0x97/0x150
ip6_dst_alloc+0x23/0x90
ip6_rt_pcpu_alloc+0x1e6/0x520
ip6_pol_route+0x56f/0x840
fib6_rule_lookup+0x334/0x630
ip6_route_output_flags+0x259/0x480
ip6_dst_lookup_tail.constprop.0+0x5c2/0x940
ip6_dst_lookup_flow+0x88/0x190
udp_tunnel6_dst_lookup+0x2a7/0x4c0
vxlan_xmit_one+0xbde/0x4a50 [vxlan]
vxlan_xmit+0x9ad/0xf20 [vxlan]
dev_hard_start_xmit+0x10e/0x360
__dev_queue_xmit+0xf95/0x18c0
arp_solicit+0x4a2/0xe00
neigh_probe+0xaa/0xf0

While the first suspect is the dst_cache, explicitly tracking the dst
owing the last device reference via probes proved such dst is held by
the nexthop in the originating fib6_info.

Similar to commit f5b51fe804ec ("ipv6: route: purge exception on
removal"), we need to explicitly release the originating fib info when
disconnecting a to-be-removed device from a live ipv6 dst: move the
fib6_info cleanup into ip6_dst_ifdown().

Tested running:

./pmtu.sh cleanup_ipv6_exception

in a tight loop for more than 400 iterations with no spat, running an
unpatched kernel I observed a splat every ~10 iterations.

Affected products

VendorProductAffectedFixed
Linux Linux 5.3 5.15.181

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 6.12.3-1 —
Debian 13 linux 6.12.3-1 —
Debian 12 linux 6.1.123-1 —
Debian 11 linux-6.1 6.1.128-1~deb11u1 DLA-4076-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1072.74 —
Ubuntu 24.04 LTS linux 6.8.0-58.60 USN-7449-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1027.29 USN-7449-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1027.32 USN-7449-1
Ubuntu 24.04 LTS linux-azure-6.11 6.11.0-1012.12~24.04.1 —
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1014.15 USN-7468-1
Ubuntu 24.04 LTS linux-gcp 6.8.0-1028.30 USN-7450-1
Ubuntu 24.04 LTS linux-gcp-6.11 6.11.0-1011.11~24.04.1 —
Ubuntu 24.04 LTS linux-gke 6.8.0-1023.27 USN-7450-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1010.12 USN-7450-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1024.24 USN-7449-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1026.29 USN-7449-1
Ubuntu 24.04 LTS linux-nvidia-6.11 6.11.0-1007.7 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1026.29.1 USN-7449-1
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1008.8 —
Ubuntu 24.04 LTS linux-oem-6.11 6.11.0-1015.15 USN-7310-1
Ubuntu 24.04 LTS linux-oem-6.8 6.8.0-1026.26 USN-7449-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1024.25 USN-7449-1
Ubuntu 24.04 LTS linux-raspi 6.8.0-1028.32 USN-7524-1
Ubuntu 24.04 LTS linux-realtime +1 No fix yet —
Ubuntu 24.04 LTS linux-riscv +1 6.8.0-58.60.1 USN-7449-1
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1017.18 —
Ubuntu 22.04 LTS linux +1 5.15.0-144.157 USN-7654-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1088.95 USN-7654-1
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1027.29~22.04.1 USN-7451-1
Ubuntu 22.04 LTS linux-azure 5.15.0-1094.103 USN-7711-1
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1027.32~22.04.1 USN-7449-1
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1094.103.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1087.96 USN-7654-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1028.30~22.04.1 USN-7452-1
Ubuntu 22.04 LTS linux-gke +1 5.15.0-1085.91 USN-7654-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1070.78 USN-7654-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-58.60~22.04.1 USN-7449-2
Ubuntu 22.04 LTS linux-ibm 5.15.0-1080.83 USN-7654-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1024.24~22.04.1 —
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1083.89 USN-7654-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1084.89 USN-7654-4
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1082.83 USN-7654-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1026.29~22.04.1 USN-7449-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1041.41 USN-7654-1
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1030.30 USN-7654-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1024.25~22.04.1 USN-7449-1
Ubuntu 22.04 LTS linux-raspi 5.15.0-1083.86 USN-7686-1
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 +1 6.8.0-58.60.1~22.04.1 USN-7449-1
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1052.56 USN-7654-5
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Show 10 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2023.24 USN-7523-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1020.21 USN-7453-1
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1081.83 USN-7654-2
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1088.97 USN-7654-2
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1020.21~22.04.1 —
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-78.78+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1088.95+fips1 USN-7654-3
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1094.103+fips1 USN-7712-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-144.157+fips1 USN-7654-3
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1087.96+fips1 USN-7654-3
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips +3 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 5.15.0-1088.95~20.04.1 USN-7654-1
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1094.103~20.04.1 USN-7712-2
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1087.96~20.04.2 USN-7654-1
Ubuntu Pro 20.04 LTS linux-hwe-5.15 +1 5.15.0-144.157~20.04.1 USN-7654-1
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1080.83~20.04.1 USN-7654-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1083.89~20.04.1 USN-7655-1
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1041.41~20.04.1 USN-7654-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1085.91~20.04.3 USN-7654-1
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1083.87~20.04.1 —
Ubuntu Pro 18.04 LTS linux-aws-5.4 +6 No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.3.1 SUSE-SU-2025:01951-1
SLES 15 SP7 kernel-azure +2 6.4.0-150700.20.3.1 SUSE-SU-2025:01967-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.3.1.150700.17.2.1 SUSE-SU-2025:01951-1
SLES 15 SP6 kernel-64kb +3 6.4.0-150600.23.47.2 SUSE-SU-2025:1180-1
SLES 15 SP6 kernel-azure +1 6.4.0-150600.8.34.2 SUSE-SU-2025:1177-1
SLES 15 SP6 kernel-coco +3 6.4.0-15061.21.coco15sp6.1 SUSE-SU-2025:01919-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.47.2.150600.12.20.2 SUSE-SU-2025:1180-1
SLES 15 SP6 kernel-docs +2 6.4.0-150600.23.47.1 SUSE-SU-2025:1180-1
SLES 15 SP6 kernel-syms-azure 6.4.0-150600.8.34.1 SUSE-SU-2025:1177-1
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLE Micro 6.1 kernel-default-base 6.4.0-28.1.21.6 SUSE-SU-2025:20270-1
SLE Micro 6.1 kernel-livepatch-MICRO-6-0_Update_6 +1 1-3.1 SUSE-SU-2025:20270-1, SUSE-SU-2025:20260-1
SLE Micro 6.1 kernel-rt +4 6.4.0-28.1 SUSE-SU-2025:20270-1, SUSE-SU-2025:20260-1
SLE Micro 6.0 kernel-default-base 6.4.0-28.1.21.6 SUSE-SU-2025:20192-1
SLE Micro 6.0 kernel-livepatch-MICRO-6-0_Update_6 +1 1-3.1 SUSE-SU-2025:20192-1, SUSE-SU-2025:20190-1
SLE Micro 6.0 kernel-rt +4 6.4.0-28.1 SUSE-SU-2025:20192-1, SUSE-SU-2025:20190-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.3.1 SUSE-SU-2025:01951-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_1 1-150700.15.3.1 SUSE-SU-2025:01951-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.47.2 SUSE-SU-2025:1180-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_10 1-150600.1.5.1 SUSE-SU-2025:1178-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_10 1-150600.13.5.1 SUSE-SU-2025:1180-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.34.1 SUSE-SU-2025:1178-1
ReleasePackageFixed inAdvisory
openSUSE Leap 15.6 dtb-aarch64 +4 6.4.0-150600.23.47.1 SUSE-SU-2025:1180-1
openSUSE Leap 15.6 kernel-64kb +5 6.4.0-150600.23.47.2 SUSE-SU-2025:1180-1
openSUSE Leap 15.6 kernel-azure +1 6.4.0-150600.8.34.2 SUSE-SU-2025:1177-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.47.2.150600.12.20.2 SUSE-SU-2025:1180-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.34.1 SUSE-SU-2025:1178-1
openSUSE Leap 15.6 kernel-syms-azure 6.4.0-150600.8.34.1 SUSE-SU-2025:1177-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.1.124-134.200 1.0-0.amzn2023 ALAS2023-2025-809
Amazon Linux 2023 perf +14 6.1.124-134.200.amzn2023 ALAS2023-2025-809

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.64.2-1 —
Azure Linux 2 (CBL-Mariner) kernel 5.15.182.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-101.33.4.3.el10uek ELSA-2025-20530, ELSA-2025-20480
Oracle Linux 8 bpftool +18 5.15.0-310.184.5.2.el9uek ELSA-2025-20470

Advisories 37

References