Description
In the Linux kernel, the following vulnerability has been resolved:
lwt: Fix return values of BPF xmit ops
BPF encap ops can return different types of positive values, such like
NET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function
skb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return
values would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in
ip(6)_finish_output2. When this happens, skbs that have been freed would
continue to the neighbor subsystem, causing use-after-free bug and
kernel crashes.
To fix the incorrect behavior, skb_do_redirect return values can be
simply discarded, the same as tc-egress behavior. On the other hand,
bpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU
information. Thus convert its return values to avoid the conflict with
LWTUNNEL_XMIT_CONTINUE.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.10 | 5.4.257 |
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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.5.3-1 | — |
| Debian 13 | linux | 6.5.3-1 | — |
| Debian 12 | linux | 6.1.55-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1035.37 | — |
| Ubuntu 24.04 LTS | linux-intel +9 | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-94.104 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1053.58 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1056.64 | — |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1056.64.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1051.59 | — |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1050.55 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1036.42 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1046.49 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1047.53 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1044.44 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1022.22 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1009.9 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1051.57 | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1027.31 | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-169.187 | — |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1116.126 | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1053.58~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1121.128 | — |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1056.64~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1076.82 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1120.129 | — |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1051.59~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-94.104~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-ibm | 5.4.0-1063.68 | — |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1046.49~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1048.54~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-iot | 5.4.0-1028.29 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1104.111 | — |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1022.22~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1115.124 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1051.57~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1100.112 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1049.53~20.04.2 | — |
| Ubuntu 20.04 LTS | linux-xilinx-zynqmp | 5.4.0-1035.39 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1046.48 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1054.60 | — |
| 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-updates 22.04 LTS | linux-aws-fips | 5.15.0-1053.58+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-94.104+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1055.63+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1116.126+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1121.128+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1090.100 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1120.129+fips1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux +5 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux-aws-5.4 | 5.4.0-1116.126~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-azure-5.4 | 5.4.0-1121.128~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-gcp-5.4 | 5.4.0-1120.129~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-hwe-5.4 | 5.4.0-169.187~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-ibm-5.4 | 5.4.0-1063.68~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-oracle-5.4 | 5.4.0-1115.124~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-raspi-5.4 | 5.4.0-1100.112~18.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | bpftool | 7.3.0-427.13.1.el9_4 | RHSA-2024:2394 |
| RHEL 9 | rv +64 | 5.14.0-427.13.1.el9_4 | RHSA-2024:2394 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.22.1 | SUSE-SU-2025:4057-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.18.1 | SUSE-SU-2025:4132-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.22.1.150700.17.15.1 | SUSE-SU-2025:4057-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
| SLES 12 SP5 | kernel-syms +2 | 4.12.14-122.280.1 | SUSE-SU-2025:4189-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.1 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20898-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20851-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20870-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20851-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.22.1 | SUSE-SU-2025:4057-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_6 | 1-150700.1.3.1 | SUSE-SU-2025:4141-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_6 | 1-150700.15.3.1 | SUSE-SU-2025:4057-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_16 | 1-150600.1.3.1 | SUSE-SU-2025:3751-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_16 | 1-150600.13.3.1 | SUSE-SU-2025:03600-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.280.1 | SUSE-SU-2025:4189-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_74 | 1-8.5.1 | SUSE-SU-2025:4189-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.22.1 | SUSE-SU-2025:4141-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.55-75.123 | 1.0-0.amzn2023 | ALAS2023-2023-356 |
| Amazon Linux 2023 | perf +12 | 6.1.55-75.123.amzn2023 | ALAS2023-2023-356 |
Advisories 15
- WID-SEC-2025-2087 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 18, 2026
- RHSA-2024:2394 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- WID-SEC-2026-0349 Dell Avamar und NetWorker: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 17, 2026
- SUSE-SU-2025:4189-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20851-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03634-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4141-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20861-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20870-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03600-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20898-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2023-2023-356 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026
- SUSE-SU-2025:3751-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4132-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4057-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://git.kernel.org/stable/c/67f8f2bae8e7ac72e09def2b667e44704c4d1ee1
- https://git.kernel.org/stable/c/a97f221651fcdc891166e9bc270e3d9bfa5a0080
- https://git.kernel.org/stable/c/e3f647e4b642f9f6d32795a16f92c116c138d2af
- https://git.kernel.org/stable/c/065d5f17096ec9161180e2c890afdff4dc6125f2
- https://git.kernel.org/stable/c/d68c17402442f5f494a2c3ebde5cb82f6aa9160a
- https://git.kernel.org/stable/c/65583f9e070db7bece20710cfa2e3daeb0b831d9
- https://git.kernel.org/stable/c/29b22badb7a84b783e3a4fffca16f7768fb31205