Description
In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_skbmod: Skip non-Ethernet packets
Currently tcf_skbmod_act() assumes that packets use Ethernet as their L2
protocol, which is not always the case. As an example, for CAN devices:
$ ip link add dev vcan0 type vcan
$ ip link set up vcan0
$ tc qdisc add dev vcan0 root handle 1: htb
$ tc filter add dev vcan0 parent 1: protocol ip prio 10 \
matchall action skbmod swap mac
Doing the above silently corrupts all the packets. Do not perform skbmod
actions for non-Ethernet packets.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.9 | 4.19.199 |
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 | 5.14.6-1 | — |
| Debian 13 | linux | 5.14.6-1 | — |
| Debian 12 | linux | 5.14.6-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +22 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-88.99 | — |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1057.60 | — |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1059.62 | — |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1019.22 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1053.57 | — |
| Ubuntu 20.04 LTS | linux-gke +26 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gkeop | 5.4.0-1024.25 | — |
| Ubuntu 20.04 LTS | linux-ibm | 5.4.0-1005.6 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1047.49 | — |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1055.59 | — |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1044.48 | — |
| Ubuntu 18.04 LTS | linux-aws-5.4 | 5.4.0-1057.60~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-azure-5.4 | 5.4.0-1059.62~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-5.4 | 5.4.0-1053.57~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-87.98~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-oracle-5.4 | 5.4.0-1055.59~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1044.48~18.04.1 | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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 | 5.4.0-1069.73+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1073.76+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1034.40 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1067.71~20.04.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux +5 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.6 TUS | perf +17 | 4.18.0-372.111.1.el8_6 | RHSA-2024:4447 |
| RHEL 8.6 E4S | perf +25 | 4.18.0-372.111.1.el8_6 | RHSA-2024:4447 |
| RHEL 8.6 AUS | perf +17 | 4.18.0-372.111.1.el8_6 | RHSA-2024:4447 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | kernel-azure +2 | 4.12.14-16.191.1 | SUSE-SU-2024:2360-1 |
| SLES 12 SP5 | kernel-docs +4 | 4.12.14-122.222.1 | SUSE-SU-2024:2561-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP5 | kernel-azure +2 | 4.12.14-16.191.1 | SUSE-SU-2024:2360-1 |
| SLES for SAP 12 SP5 | kernel-syms +2 | 4.12.14-122.222.1 | SUSE-SU-2024:2561-1 |
| SLE Real Time 12 SP5 | kernel-rt +3 | 4.12.14-10.191.1 | SUSE-SU-2024:2381-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.222.1 | SUSE-SU-2024:2561-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_58 | 1-8.3.1 | SUSE-SU-2024:2561-1 |
Advisories 4
- RHSA-2024:4447 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Sep 11, 2026
- SUSE-SU-2024:2561-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:2360-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:2381-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://git.kernel.org/stable/c/e4fdca366806f6bab374d1a95e626a10a3854b0c
- https://git.kernel.org/stable/c/a88414fb1117f2fe65fb88e45ba694e1d09d5024
- https://git.kernel.org/stable/c/071729150be9e1d1b851b70efb6d91ee9269d57b
- https://git.kernel.org/stable/c/34f1e1f657fae2891b485a3b2b95fe4d2aef9f0d
- https://git.kernel.org/stable/c/727d6a8b7ef3d25080fad228b2c4a1d4da5999c6