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.
CVSS Details
- CVSS 3.1 Base Score: 9.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade python-perf-debuginfoUpgrade kernel-headersUpgrade kernel-tools-develUpgrade perf-debuginfoUpgrade bpftool-debuginfoUpgrade kernel-tools-debuginfoUpgrade kernel-debuginfoUpgrade kernel-livepatch-5.15.128-80.144Upgrade perfUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-livepatch-5.10.192-182.736Upgrade bpftoolUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-develUpgrade python-perfUpgrade kernelUpgrade kernel-tools | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade perfUpgrade python3-perfUpgrade kernel-debuginfoUpgrade kernel-livepatch-6.1.49-69.116Upgrade kernel-tools-develUpgrade kernel-libbpf-develUpgrade kernel-debuginfo-common-aarch64Upgrade perf-debuginfoUpgrade kernel-develUpgrade kernelUpgrade bpftool-debuginfoUpgrade kernel-libbpfUpgrade kernel-toolsUpgrade kernel-debuginfo-common-x86_64Upgrade bpftoolUpgrade python3-perf-debuginfoUpgrade kernel-headersUpgrade kernel-tools-debuginfoUpgrade kernel-libbpf-static | Oct 24, 2025 | Oct 4, 2025 |
| Debian | — | Upgrade linux | Oct 6, 2025 | Oct 6, 2025 |
| Huawei Euleros 2_0_sp13 | — | Upgrade kernel-abi-stablelistsUpgrade bpftoolUpgrade kernel-toolsUpgrade kernel-tools-libsUpgrade python3-perfUpgrade kernel | Feb 3, 2026 | Feb 2, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Oct 4, 2025 |
| Ubuntu | — | Upgrade linux-nvidia-tegra-igxUpgrade linux-gcpUpgrade linux-azure-5.15Upgrade linux-oracleUpgrade linux-ibmUpgrade linux-intel-iot-realtimeUpgrade linux-intel-iotgUpgrade linux-kvmUpgrade linux-oracle-5.15Upgrade linux-nvidiaUpgrade linux-intel-iotg-5.15Upgrade linux-gkeopUpgrade linux-xilinx-zynqmpUpgrade linux-gcp-5.15Upgrade linuxUpgrade linux-realtimeUpgrade linux-nvidia-tegraUpgrade linux-raspiUpgrade linux-awsUpgrade linux-bluefieldUpgrade linux-gkeUpgrade linux-riscv-5.15Upgrade linux-azureUpgrade linux-ibm-5.15Upgrade linux-lowlatency-hwe-5.15Upgrade linux-aws-5.15Upgrade linux-lowlatencyUpgrade linux-hwe-5.15Upgrade linux-nvidia-tegra-5.15 | Oct 10, 2025 | Oct 4, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 15, 2025 | Oct 4, 2025 |
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