Description
In the Linux kernel, the following vulnerability has been resolved:
net: tunnels: annotate lockless accesses to dev->needed_headroom
IP tunnels can apparently update dev->needed_headroom
in their xmit path.
This patch takes care of three tunnels xmit, and also the
core LL_RESERVED_SPACE() and LL_RESERVED_SPACE_EXTRA()
helpers.
More changes might be needed for completeness.
BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit
read to 0xffff88815b9da0ec of 2 bytes by task 888 on cpu 1:
ip_tunnel_xmit+0x1270/0x1730 net/ipv4/ip_tunnel.c:803
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
ipgre_xmit+0x516/0x570 net/ipv4/ip_gre.c:661
__netdev_start_xmit include/linux/netdevice.h:4881 [inline]
netdev_start_xmit include/linux/netdevice.h:4895 [inline]
xmit_one net/core/dev.c:3580 [inline]
dev_hard_start_xmit+0x127/0x400 net/core/dev.c:3596
__dev_queue_xmit+0x1007/0x1eb0 net/core/dev.c:4246
dev_queue_xmit include/linux/netdevice.h:3051 [inline]
neigh_direct_output+0x17/0x20 net/core/neighbour.c:1623
neigh_output include/net/neighbour.h:546 [inline]
ip_finish_output2+0x740/0x840 net/ipv4/ip_output.c:228
ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:316
NF_HOOK_COND include/linux/netfilter.h:291 [inline]
ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:430
dst_output include/net/dst.h:444 [inline]
ip_local_out+0x64/0x80 net/ipv4/ip_output.c:126
iptunnel_xmit+0x34a/0x4b0 net/ipv4/ip_tunnel_core.c:82
ip_tunnel_xmit+0x1451/0x1730 net/ipv4/ip_tunnel.c:813
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
ipgre_xmit+0x516/0x570 net/ipv4/ip_gre.c:661
__netdev_start_xmit include/linux/netdevice.h:4881 [inline]
netdev_start_xmit include/linux/netdevice.h:4895 [inline]
xmit_one net/core/dev.c:3580 [inline]
dev_hard_start_xmit+0x127/0x400 net/core/dev.c:3596
__dev_queue_xmit+0x1007/0x1eb0 net/core/dev.c:4246
dev_queue_xmit include/linux/netdevice.h:3051 [inline]
neigh_direct_output+0x17/0x20 net/core/neighbour.c:1623
neigh_output include/net/neighbour.h:546 [inline]
ip_finish_output2+0x740/0x840 net/ipv4/ip_output.c:228
ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:316
NF_HOOK_COND include/linux/netfilter.h:291 [inline]
ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:430
dst_output include/net/dst.h:444 [inline]
ip_local_out+0x64/0x80 net/ipv4/ip_output.c:126
iptunnel_xmit+0x34a/0x4b0 net/ipv4/ip_tunnel_core.c:82
ip_tunnel_xmit+0x1451/0x1730 net/ipv4/ip_tunnel.c:813
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
ipgre_xmit+0x516/0x570 net/ipv4/ip_gre.c:661
__netdev_start_xmit include/linux/netdevice.h:4881 [inline]
netdev_start_xmit include/linux/netdevice.h:4895 [inline]
xmit_one net/core/dev.c:3580 [inline]
dev_hard_start_xmit+0x127/0x400 net/core/dev.c:3596
__dev_queue_xmit+0x1007/0x1eb0 net/core/dev.c:4246
dev_queue_xmit include/linux/netdevice.h:3051 [inline]
neigh_direct_output+0x17/0x20 net/core/neighbour.c:1623
neigh_output include/net/neighbour.h:546 [inline]
ip_finish_output2+0x740/0x840 net/ipv4/ip_output.c:228
ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:316
NF_HOOK_COND include/linux/netfilter.h:291 [inline]
ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:430
dst_output include/net/dst.h:444 [inline]
ip_local_out+0x64/0x80 net/ipv4/ip_output.c:126
iptunnel_xmit+0x34a/0x4b0 net/ipv4/ip_tunnel_core.c:82
ip_tunnel_xmit+0x1451/0x1730 net/ipv4/ip_tunnel.c:813
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
ipgre_xmit+0x516/0x570 net/ipv4/ip_gre.c:661
__netdev_start_xmit include/linux/netdevice.h:4881 [inline]
netdev_start_xmit include/linux/netdevice.h:4895 [inline]
xmit_one net/core/dev.c:3580 [inline]
dev_hard_start_xmit+0x127/0x400 net/core/dev.c:3596
__dev_queue_xmit+0x1007/0x1eb0 net/core/dev.c:4246
dev_queue_xmit include/linux/netdevice.h:3051 [inline]
neigh_direct_output+0x17/0x20 net/core/neighbour.c:1623
neigh_output include/net/neighbour.h:546 [inline]
ip_finish_output2+0x740/0x840 net/ipv4/ip_output.c:228
ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:316
NF_HOOK_COND include/linux/netfilter.h:291 [inline]
ip_output+0xe5/0x1b0 net/i
---truncated---
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.7 | 4.14.311 |
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 | 6.1.25-1 | — |
| Debian 13 | linux | 6.1.25-1 | — |
| Debian 12 | linux | 6.1.25-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1022.24 | — |
| Ubuntu 24.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 22.04 LTS | linux | 5.15.0-79.86 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1042.47 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1045.52 | — |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1045.52.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1039.47 | — |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1039.44 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1025.30 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1035.38 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1037.42 | — |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-79.88 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1030.30 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1016.16 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1002.2 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1040.46 | — |
| Ubuntu 22.04 LTS | linux-riscv +31 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1025.29 | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-156.173 | — |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1107.115 | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1041.46~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1114.120 | — |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1045.52~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1068.74 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1110.119 | — |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1039.47~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-hwe-5.15 | 5.15.0-79.86~20.04.2 | — |
| Ubuntu 20.04 LTS | linux-ibm | 5.4.0-1054.59 | — |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1036.39~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1037.42~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-iot | 5.4.0-1019.20 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1096.102 | — |
| Ubuntu 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-79.88~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1016.16~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1106.115 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1040.46~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1091.102 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1038.42~20.04.2 | — |
| Ubuntu 20.04 LTS | linux-xilinx-zynqmp | 5.4.0-1027.31 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 10 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 | 5.15.0-1036.38 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1043.48 | — |
| 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 20.04 LTS | linux-aws-fips | 5.4.0-1107.115+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1113.119+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1082.91 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1110.119+fips1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux +5 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux-aws-5.4 | 5.4.0-1107.115~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-azure-5.4 | 5.4.0-1113.119~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-gcp-5.4 | 5.4.0-1110.119~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-hwe-5.4 | 5.4.0-156.173~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-ibm-5.4 | 5.4.0-1054.59~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-oracle-5.4 | 5.4.0-1106.115~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-raspi-5.4 | 5.4.0-1091.102~18.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | kernel-64kb +6 | 5.14.21-150500.55.110.1 | SUSE-SU-2025:02173-1 |
| SLES 15 SP5 | kernel-default-base | 5.14.21-150500.55.110.1.150500.6.51.3 | SUSE-SU-2025:02173-1 |
| SLES 15 SP4 | kernel-64kb +2 | 5.14.21-150400.24.240.2 | SUSE-SU-2026:4284-1 |
| SLES 15 SP4 | kernel-default-base | 5.14.21-150400.24.240.2.150400.24.120.2 | SUSE-SU-2026:4284-1 |
| SLES 15 SP4 | kernel-docs +3 | 5.14.21-150400.24.240.1 | SUSE-SU-2026:4284-1 |
| SLES 12 SP5 | kernel-syms +2 | 4.12.14-122.261.1 | SUSE-SU-2025:01983-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP5 | kernel-default-base | 5.14.21-150500.55.110.1.150500.6.51.3 | SUSE-SU-2025:02173-1 |
| SLES for SAP 15 SP5 | kernel-docs +4 | 5.14.21-150500.55.110.1 | SUSE-SU-2025:02173-1 |
| SLES for SAP 15 SP4 | kernel-default | 5.14.21-150400.24.240.2 | SUSE-SU-2026:4284-1 |
| SLES for SAP 15 SP4 | kernel-default-base | 5.14.21-150400.24.240.2.150400.24.120.2 | SUSE-SU-2026:4284-1 |
| SLES for SAP 15 SP4 | kernel-docs +3 | 5.14.21-150400.24.240.1 | SUSE-SU-2026:4284-1 |
| SLE Micro 5.5 | kernel-default-base | 5.14.21-150500.55.110.1.150500.6.51.3 | SUSE-SU-2025:02173-1 |
| SLE Micro 5.5 | kernel-rt +1 | 5.14.21-150500.13.97.1 | SUSE-SU-2025:01966-1 |
| SLE Micro 5.5 | kernel-source +1 | 5.14.21-150500.55.110.1 | SUSE-SU-2025:02173-1 |
| SLE Micro 5.4 | kernel-default | 5.14.21-150400.24.240.2 | SUSE-SU-2026:4284-1 |
| SLE Micro 5.4 | kernel-default-base | 5.14.21-150400.24.240.2.150400.24.120.2 | SUSE-SU-2026:4284-1 |
| SLE Micro 5.4 | kernel-rt +1 | 5.14.21-150400.15.186.1 | SUSE-SU-2026:4279-1 |
| SLE Micro 5.4 | kernel-source | 5.14.21-150400.24.240.1 | SUSE-SU-2026:4284-1 |
| SLE Micro 5.3 | kernel-default | 5.14.21-150400.24.240.2 | SUSE-SU-2026:4284-1 |
| SLE Micro 5.3 | kernel-default-base | 5.14.21-150400.24.240.2.150400.24.120.2 | SUSE-SU-2026:4284-1 |
| SLE Micro 5.3 | kernel-rt +1 | 5.14.21-150400.15.186.1 | SUSE-SU-2026:4279-1 |
| SLE Micro 5.3 | kernel-source | 5.14.21-150400.24.240.1 | SUSE-SU-2026:4284-1 |
| SLE Live Patching 15 SP5 | kernel-default | 5.14.21-150500.55.110.1 | SUSE-SU-2025:02173-1 |
| SLE Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_27 | 1-150500.11.7.1 | SUSE-SU-2025:02173-1 |
| SLE Live Patching 15 SP4 | kernel-default | 5.14.21-150400.24.240.2 | SUSE-SU-2026:4284-1 |
| SLE Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_59 | 1-150400.9.5.1 | SUSE-SU-2026:4284-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.261.1 | SUSE-SU-2025:01983-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_69 | 1-8.3.1 | SUSE-SU-2025:01983-1 |
| SLE HPC 15 SP5 | kernel-64kb +5 | 5.14.21-150500.55.110.1 | SUSE-SU-2025:02173-1 |
| SLE HPC 15 SP5 | kernel-default-base | 5.14.21-150500.55.110.1.150500.6.51.3 | SUSE-SU-2025:02173-1 |
| SLE HPC 15 SP4 | kernel-64kb +1 | 5.14.21-150400.24.240.2 | SUSE-SU-2026:4284-1 |
| SLE HPC 15 SP4 | kernel-default-base | 5.14.21-150400.24.240.2.150400.24.120.2 | SUSE-SU-2026:4284-1 |
| SLE HPC 15 SP4 | kernel-docs +3 | 5.14.21-150400.24.240.1 | SUSE-SU-2026:4284-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.21-1.45 | 1.0-0.amzn2023 | ALAS2023-2023-148 |
| Amazon Linux 2023 | perf +12 | 6.1.21-1.45.amzn2023 | ALAS2023-2023-148 |
| Amazon Linux 2 | kernel-livepatch-4.14.311-233.529 | 1.0-0.amzn2 | ALAS2-2025-2909, ALAS2-2025-2892 |
| Amazon Linux 2 | perf +8 | 4.14.311-233.529.amzn2 | ALAS2-2025-2909, ALAS2-2025-2892 |
Advisories 9
- SUSE-SU-2026:4279-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 23, 2026
- SUSE-SU-2026:4284-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 23, 2026
- WID-SEC-2025-0932 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 22, 2026
- SUSE-SU-2025:02173-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:01966-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:01983-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2023-148 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 22, 2025
- ALAS2-2025-2909 Important: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 29, 2025
- ALAS2-2025-2892 Moderate: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jun 24, 2025
References
- https://git.kernel.org/stable/c/8e206f66d824b3b28a7f9ee1366dfc79a937bb46
- https://git.kernel.org/stable/c/51f3bd3765bc5ca4583af07a00833da00d2ace1d
- https://git.kernel.org/stable/c/5aaab217c8f5387b9c5fff9e940d80f135e04366
- https://git.kernel.org/stable/c/be59b87ee4aed81db7c10e44f603866a0ac3ca5d
- https://git.kernel.org/stable/c/e0a557fc1daf5c1086e47150a4571aebadbb62be
- https://git.kernel.org/stable/c/a69b72b57b7d269e833e520ba7500d556e8189b6
- https://git.kernel.org/stable/c/9b86a8702b042ee4e15d2d46375be873a6a8834f
- https://git.kernel.org/stable/c/4b397c06cb987935b1b097336532aa6b4210e091