Description
In the Linux kernel, the following vulnerability has been resolved:
vxlan: Annotate FDB data races
The 'used' and 'updated' fields in the FDB entry structure can be
accessed concurrently by multiple threads, leading to reports such as
[1]. Can be reproduced using [2].
Suppress these reports by annotating these accesses using
READ_ONCE() / WRITE_ONCE().
[1]
BUG: KCSAN: data-race in vxlan_xmit / vxlan_xmit
write to 0xffff942604d263a8 of 8 bytes by task 286 on cpu 0:
vxlan_xmit+0xb29/0x2380
dev_hard_start_xmit+0x84/0x2f0
__dev_queue_xmit+0x45a/0x1650
packet_xmit+0x100/0x150
packet_sendmsg+0x2114/0x2ac0
__sys_sendto+0x318/0x330
__x64_sys_sendto+0x76/0x90
x64_sys_call+0x14e8/0x1c00
do_syscall_64+0x9e/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff942604d263a8 of 8 bytes by task 287 on cpu 2:
vxlan_xmit+0xadf/0x2380
dev_hard_start_xmit+0x84/0x2f0
__dev_queue_xmit+0x45a/0x1650
packet_xmit+0x100/0x150
packet_sendmsg+0x2114/0x2ac0
__sys_sendto+0x318/0x330
__x64_sys_sendto+0x76/0x90
x64_sys_call+0x14e8/0x1c00
do_syscall_64+0x9e/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x00000000fffbac6e -> 0x00000000fffbac6f
Reported by Kernel Concurrency Sanitizer on:
CPU: 2 UID: 0 PID: 287 Comm: mausezahn Not tainted 6.13.0-rc7-01544-gb4b270f11a02 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
[2]
#!/bin/bash
set +H
echo whitelist > /sys/kernel/debug/kcsan
echo !vxlan_xmit > /sys/kernel/debug/kcsan
ip link add name vx0 up type vxlan id 10010 dstport 4789 local 192.0.2.1
bridge fdb add 00:11:22:33:44:55 dev vx0 self static dst 198.51.100.1
taskset -c 0 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q &
taskset -c 2 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q &
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 3.7 | 5.4.294 |
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 | 6.12.32-1 | — |
| Debian 13 | linux | 6.12.32-1 | — |
| Debian 12 | linux | 6.1.147-1 | DSA-5973-1 |
| Debian 11 | linux | 5.10.244-1 | DLA-4327-1 |
| Debian 11 | linux-6.1 | 6.1.153-1~deb11u1 | DLA-4328-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1016.20 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1074.76 | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.04 | linux-azure | 6.14.0-1012.12 | USN-7770-1 |
| Ubuntu 25.04 | linux-raspi | 6.14.0-1014.14 | USN-7789-2 |
| Ubuntu 24.04 LTS | linux | 6.8.0-100.100 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1046.49 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-aws-6.14 +1 | 6.14.0-1013.13~24.04.1 | USN-7789-1, USN-7769-3 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1046.52 | USN-8074-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1046.53 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia-6.14 | 6.14.0-1007.7 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1047.50 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gcp-6.14 | 6.14.0-1016.17~24.04.1 | USN-7769-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1043.48 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1030.33 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-hwe-6.14 | 6.14.0-32.32~24.04.1 | USN-7769-3 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1044.44 | USN-8028-8 |
| Ubuntu 24.04 LTS | linux-intel +10 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-100.100.1 | USN-8052-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1046.49.1 | USN-8028-7 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oem-6.14 | 6.14.0-1012.12 | USN-7771-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1043.44 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1047.51 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-riscv-6.14 | 6.14.0-32.32.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1023.24 | USN-8052-2 |
Show 19 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-152.162 | USN-7704-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1090.97 | USN-7704-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 +1 | 6.8.0-1046.49~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1094.103 | USN-7711-1 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1094.103.1 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1046.53~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1090.99 | USN-7704-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1047.50~22.04.2 | USN-8031-1 |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1087.93 | USN-7704-5 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1073.81 | USN-7704-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-100.100~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1084.87 | USN-7704-3 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1044.44~22.04.1 | USN-8028-8 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1085.91 | USN-7704-3 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1086.91 | USN-7704-5 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-100.100.1~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1085.86 | USN-7704-4 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1043.43 | USN-7704-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1032.32 | USN-7704-1 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1088.94 | USN-7704-3 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1043.44~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1054.58 | USN-7704-1 |
| 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 | 6.8.0-2037.38 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1041.42 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | 6.14.0-1012.12~24.04.1 | USN-7769-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1083.85 | USN-7704-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1090.99 | USN-7704-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1041.42~22.04.1 | USN-8028-2 |
| 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 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1046.49+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1046.52+fips1 | USN-8074-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-100.100+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1047.50+fips1 | USN-8031-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1090.97+fips1 | USN-7704-2 |
| 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 | 5.15.0-152.162+fips1 | USN-7704-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1090.99+fips1 | USN-7704-2 |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 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 | 5.15.0-1090.97~20.04.1 | USN-7704-1 |
| 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 | 5.15.0-1090.99~20.04.1 | USN-7704-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-152.162~20.04.1 | USN-7704-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 | 5.15.0-1083.86~20.04.1 | USN-7704-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1085.91~20.04.1 | USN-7704-1 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1043.43~20.04.1 | USN-7704-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1088.94~20.04.1 | USN-7704-1 |
| Ubuntu Pro 20.04 LTS | linux-riscv-5.15 | 5.15.0-1085.89~20.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux +3 | No fix yet | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.31-35.92 +1 | 1.0-0.amzn2023 | ALAS2023-2025-1052, ALAS2023-2025-1037 |
| Amazon Linux 2023 | perf +14 | 6.1.141-155.222.amzn2023 | ALAS2023-2025-1052, ALAS2023-2025-1037 |
| Amazon Linux 2023 | perf6.12 +5 | 6.12.31-35.92.amzn2023 | ALAS2023-2025-1052 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.96.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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 | 5.15.0-312.187.5.el9uek | ELSA-2025-20552 |
| Oracle Linux 7 | kernel-uek +6 | 5.4.17-2136.346.6.el8uek | ELSA-2025-20521 |
| Oracle Linux 7 | kernel-uek-tools | 5.4.17-2136.346.6.el7uek | ELSA-2025-20521 |
Advisories 41
- WID-SEC-2025-1350 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8028-5 linux-aws, linux-aws-6.8, linux-gkeop, linux-nvidia, linux-nvidia-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-8 linux-ibm, linux-ibm-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-6 linux-hwe-6.8, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-1 linux-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-2 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-2 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-3 linux-gcp, linux-gke vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-1 linux, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-4 linux-aws-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-3 linux-realtime, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-7 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-2 linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-2 linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-1 linux-gcp-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7704-1 linux, linux-aws, linux-aws-5.15, linux-gcp, linux-gcp-5.15, linux-gkeop, linux-hwe-5.15, linux-ibm-5.15, linux-intel-iot-realtime, linux-intel-iotg-5.15, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx, linux-oracle-5.15, linux-realtime, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7789-1 linux-oracle-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7769-2 linux-realtime-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7771-1 linux-oem-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7769-1 linux, linux-aws, linux-gcp, linux-gcp-6.14, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7712-2 linux-azure-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7712-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7711-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7704-5 linux-gke, linux-kvm vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7704-4 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7704-3 linux-ibm, linux-intel-iotg, linux-oracle, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7704-2 linux-fips, linux-aws-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7769-3 linux-aws-6.14, linux-hwe-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- DLA-4327-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4328-1 linux-6.1 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-5973-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-7789-2 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- USN-7770-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- ALAS2023-2025-1052 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 10, 2025
- ELSA-2025-20552 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Sep 8, 2025
- ALAS2023-2025-1037 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 26, 2025
- ELSA-2025-20530 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Aug 18, 2025
- ELSA-2025-20521 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Aug 10, 2025
- ELSA-2025-20480 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 17, 2025
References
- https://git.kernel.org/stable/c/02a33b1035a307453a1da6ce0a1bf3676be287d7
- https://git.kernel.org/stable/c/87d076987a9ba106c83412fcd113656f71af05a1
- https://git.kernel.org/stable/c/e033da39fc6abbddab6c29624acef80757f273fa
- https://git.kernel.org/stable/c/784b78295a3a58bf052339dd669e6e03710220d3
- https://git.kernel.org/stable/c/13cba3f837903f7184d6e9b6137d5165ffe82a8f
- https://git.kernel.org/stable/c/a6644aeb8ddf196dec5f8e782293c36f065df4d7
- https://git.kernel.org/stable/c/4eceb7eae6ea7c950384c34e6dbbe872c981935f
- https://git.kernel.org/stable/c/f6205f8215f12a96518ac9469ff76294ae7bd612