Description
In the Linux kernel, the following vulnerability has been resolved:
ipv6: annotate data-race in ndisc_router_discovery()
syzbot found that ndisc_router_discovery() could read and write
in6_dev->ra_mtu without holding a lock [1]
This looks fine, IFLA_INET6_RA_MTU is best effort.
Add READ_ONCE()/WRITE_ONCE() to document the race.
Note that we might also reject illegal MTU values
(mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) in a future patch.
[1]
BUG: KCSAN: data-race in ndisc_router_discovery / ndisc_router_discovery
read to 0xffff888119809c20 of 4 bytes by task 25817 on cpu 1:
ndisc_router_discovery+0x151d/0x1c90 net/ipv6/ndisc.c:1558
ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841
icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989
ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438
ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489
NF_HOOK include/linux/netfilter.h:318 [inline]
ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500
ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590
dst_input include/net/dst.h:474 [inline]
ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79
...
write to 0xffff888119809c20 of 4 bytes by task 25816 on cpu 0:
ndisc_router_discovery+0x155a/0x1c90 net/ipv6/ndisc.c:1559
ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841
icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989
ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438
ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489
NF_HOOK include/linux/netfilter.h:318 [inline]
ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500
ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590
dst_input include/net/dst.h:474 [inline]
ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79
...
value changed: 0x00000000 -> 0xe5400659
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.15 | 5.15.199 |
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 | 6.18.8-1 | — |
| Debian 13 | linux | 6.12.69-1 | — |
| Debian 12 | linux | 6.1.162-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1022.26 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1089.91 | — |
| Ubuntu 25.10 | linux +8 | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-117.117 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1055.58 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1056.62 | USN-8278-2 |
| Ubuntu 24.04 LTS | linux-azure-6.17 | 6.17.0-1021.21~24.04.1 | USN-8604-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1058.65 | — |
| Ubuntu 24.04 LTS | linux-azure-fde-6.17 | 6.17.0-1018.18~24.04.1 | USN-8605-1 |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1058.61 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-gcp-6.17 | 6.17.0-1021.24~24.04.1 | USN-8570-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1054.60 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1041.44 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-hwe-6.17 | 6.17.0-41.41~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1055.56 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-117.117.1 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1054.57 | USN-8289-1 |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1031.31 | USN-8669-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1054.57.1 | USN-8289-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1024.24 | USN-8296-2 |
| Ubuntu 24.04 LTS | linux-oem-6.17 | 6.17.0-1030.30 | USN-8594-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1054.55 | — |
| Ubuntu 24.04 LTS | linux-oracle-6.17 | 6.17.0-1019.19~24.04.3 | USN-8570-2 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1056.60 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-riscv +20 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1032.33 | USN-8499-1 |
| Ubuntu 22.04 LTS | linux | 5.15.0-176.186 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1105.112 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1057.60~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1110.119 | USN-8180-3 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1059.65~22.04.1 | USN-8440-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1114.123 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1058.65~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1105.114 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1060.63~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1101.107 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1088.96 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-124.124~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1099.102 | USN-8180-6, USN-8180-5 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1055.56~22.04.1 | USN-8278-1 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1100.106 | USN-8180-3 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1097.102 | USN-8180-3 |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-175.185 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-117.117.1~22.04.1 | USN-8278-1 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1100.101 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1054.57~22.04.1 | USN-8289-2 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1057.57 | USN-8187-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1046.46 | USN-8187-1 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1102.108 | USN-8180-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1054.55~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-117.117~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1070.74 | USN-8275-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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 | 6.8.0-2045.46 | USN-8278-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1051.52 | USN-8278-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.17 | 6.17.0-1018.20~24.04.1 | USN-8570-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1097.99 | USN-8186-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1104.113 | USN-8186-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1051.52~22.04.1 | USN-8278-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1055.58+fips1 | USN-8278-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1059.65+fips1 | USN-8393-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-116.116+fips1 | USN-8296-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1058.61+fips1 | USN-8278-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1105.112+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1110.119+fips1 | USN-8180-4 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-176.186+fips1 | USN-8180-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1105.114+fips1 | USN-8180-2 |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 | 5.15.0-1105.112~20.04.1 | USN-8180-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1110.119~20.04.1 | USN-8243-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1106.115~20.04.1 | USN-8297-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 | 5.15.0-176.186~20.04.1 | USN-8188-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 | 5.15.0-1099.102~20.04.1 | USN-8180-5 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1100.106~20.04.1 | USN-8180-3 |
| Ubuntu Pro 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-175.185~20.04.1 | USN-8180-1 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1057.57~20.04.1 | USN-8162-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1102.108~20.04.1 | USN-8180-3 |
| Ubuntu Pro 20.04 LTS | linux-riscv-5.15 | 5.15.0-1099.103~20.04.1 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.68-92.122 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-1468, ALAS2023-2026-1455 |
| Amazon Linux 2023 | perf +14 | 1:6.1.163-186.299.amzn2023 | ALAS2023-2026-1468 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.68-92.122.amzn2023 | ALAS2023-2026-1455 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.126.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-200.74.27.el10uek | ELSA-2026-50372, ELSA-2026-50232, ELSA-2026-50160 |
| Oracle Linux 8 | bpftool +18 | 5.15.0-318.199.3.2.el9uek | ELSA-2026-50145 |
Advisories 35
- WID-SEC-2026-0421 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8604-1 linux-azure-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8440-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8499-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8393-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8669-1 linux-nvidia-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8570-1 linux-gcp-6.17, linux-realtime-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8570-2 linux-oracle-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8594-1 linux-oem-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8278-1 linux, linux-aws, linux-aws-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-ibm-6.8, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-raspi, linux-raspi-realtime, linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8289-1 linux-nvidia, linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8289-2 linux-nvidia-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8278-2 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8180-1 linux, linux-aws, linux-aws-5.15, linux-gcp, linux-gke, linux-gkeop, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8296-1 linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8297-1 linux-gcp-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8296-2 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8243-1 linux-azure-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8187-1 linux-nvidia-tegra, linux-nvidia-tegra-igx vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8275-1 linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8180-6 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8186-1 linux-intel-iot-realtime, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8188-1 linux-hwe-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8180-5 linux-ibm, linux-ibm-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8180-3 linux-azure, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-oracle-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8162-1 linux-nvidia-tegra-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8180-2 linux-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8180-4 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8605-1 linux-azure-fde-6.17 vulnerabilities Ubuntu Security Notices (USN) · Oct 17, 2026
- ELSA-2026-50372 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- ELSA-2026-50232 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Apr 15, 2026
- ALAS2023-2026-1468 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Mar 26, 2026
- ELSA-2026-50160 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Mar 20, 2026
- ELSA-2026-50145 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 10, 2026
- ALAS2023-2026-1455 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Mar 5, 2026
References
- https://git.kernel.org/stable/c/4630897eb1a039b5d7b737b8dc9521d9d4b568b5
- https://git.kernel.org/stable/c/2619499169fb1c2ac4974b0f2d87767fb543582b
- https://git.kernel.org/stable/c/fad8f4ff7928f4d52a062ffdcffa484989c79c47
- https://git.kernel.org/stable/c/2a2b9d25f801afecf2f83cacce98afa8fd73e3c9
- https://git.kernel.org/stable/c/e3c1040252e598f7b4e33a42dc7c38519bc22428
- https://git.kernel.org/stable/c/9a063f96d87efc3a6cc667f8de096a3d38d74bb5