Description
In the Linux kernel, the following vulnerability has been resolved:
tunnels: fix kasan splat when generating ipv4 pmtu error
If we try to emit an icmp error in response to a nonliner skb, we get
BUG: KASAN: slab-out-of-bounds in ip_compute_csum+0x134/0x220
Read of size 4 at addr ffff88811c50db00 by task iperf3/1691
CPU: 2 PID: 1691 Comm: iperf3 Not tainted 6.5.0-rc3+ #309
[..]
kasan_report+0x105/0x140
ip_compute_csum+0x134/0x220
iptunnel_pmtud_build_icmp+0x554/0x1020
skb_tunnel_check_pmtu+0x513/0xb80
vxlan_xmit_one+0x139e/0x2ef0
vxlan_xmit+0x1867/0x2760
dev_hard_start_xmit+0x1ee/0x4f0
br_dev_queue_push_xmit+0x4d1/0x660
[..]
ip_compute_csum() cannot deal with nonlinear skbs, so avoid it.
After this change, splat is gone and iperf3 is no longer stuck.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.9 | 5.10.191 |
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 | 6.4.11-1 | — |
| Debian 13 | linux | 6.4.11-1 | — |
| Debian 12 | linux | 6.1.52-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1033.35 | — |
| Ubuntu 24.04 LTS | linux-intel +9 | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-91.101 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1051.56 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1053.61 | — |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1053.61.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1048.56 | — |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1048.53 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1034.40 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1044.47 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1046.52 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1042.42 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1020.20 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1007.7 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1049.55 | — |
| 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-aws-5.15 | 5.15.0-1051.56~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1053.61~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1048.56~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-91.101~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1044.47~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1046.52~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1020.20~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1049.55~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1047.51~20.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 3 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 | 5.15.0-1044.46 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1052.58 | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips | No fix yet | — |
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 | 6.4.0-150600.23.78.1 | SUSE-SU-2025:4140-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.55.1 | SUSE-SU-2025:4128-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.78.1.150600.12.34.2 | SUSE-SU-2025:4140-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.1 | kernel-default-base | 6.4.0-36.1.21.13 | SUSE-SU-2025:21056-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-38.1 | SUSE-SU-2025:21064-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-36.1 | SUSE-SU-2025:21056-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-36.1.21.13 | SUSE-SU-2025:21040-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-38.1 | SUSE-SU-2025:21052-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-36.1 | SUSE-SU-2025:21040-1 |
| 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 | 6.4.0-150600.23.78.1 | SUSE-SU-2025:4140-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_17 | 1-150600.1.3.1 | SUSE-SU-2025:4301-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_17 | 1-150600.13.5.1 | SUSE-SU-2025:4140-1 |
| 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 | 6.4.0-150600.10.58.1 | SUSE-SU-2025:4301-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.78.1 | SUSE-SU-2025:4140-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.55.1 | SUSE-SU-2025:4128-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.78.1.150600.12.34.2 | SUSE-SU-2025:4140-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.58.1 | SUSE-SU-2025:4301-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.49-69.116 | 1.0-0.amzn2023 | ALAS2023-2023-330 |
| Amazon Linux 2023 | perf +12 | 6.1.49-69.116.amzn2023 | ALAS2023-2023-330 |
Advisories 12
- WID-SEC-2025-2194 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2025:4140-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21056-1 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-2025:21040-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21052-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21064-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2023-2023-330 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026
- SUSE-SU-2025:4128-1 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
- SUSE-SU-2025:4301-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://git.kernel.org/stable/c/5850c391fd7e25662334cb3cbf29a62bcbff1084
- https://git.kernel.org/stable/c/e95808121953410db8c59f0abfde70ac0d34222c
- https://git.kernel.org/stable/c/da5f42a6e7485fbb7a6dbd6a2b3045e19e4df5cc
- https://git.kernel.org/stable/c/fe6a9f7516735be9fdabab00e47ef7a3403a174d
- https://git.kernel.org/stable/c/6a7ac3d20593865209dceb554d8b3f094c6bd940