Description
In the Linux kernel, the following vulnerability has been resolved:
net/sched: fix packet loop on netem when duplicate is on
When netem duplicates a packet it re-enqueues the copy at the root qdisc.
If another netem sits in the tree the copy can be duplicated
again, recursing until the stack or memory is exhausted.
The original duplication guard temporarily zeroed q->duplicate around
the re-enqueue, but that does not cover all cases because it is
per-qdisc state shared across all concurrent enqueue paths
and is not safe without additional locking.
Use the skb tc_depth field introduced in an earlier patch:
- increment it on the duplicate before re-enqueue
- skip duplication for any skb whose tc_depth is already non-zero.
This marks the packet itself rather than mutating qdisc state,
therefore it is safe regardless of tree topology or concurrency.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 2.6.12 | 6.12.93 |
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 | 7.0.12-1 | — |
| Debian 13 | linux | 6.12.94-1 | — |
| Debian 12 | linux | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-28.28 | — |
| Ubuntu 26.04 LTS | linux-aws +2 | 7.0.0-1009.9 | USN-8618-1, USN-8603-1 |
| Ubuntu 26.04 LTS | linux-gcp +1 | 7.0.0-1008.8 | USN-8593-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1003.4 | — |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1010.10 | USN-8603-1, USN-8593-1 |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1016.16 | USN-8663-1 |
| Ubuntu 26.04 LTS | linux-nvidia-bos | 7.0.0-2016.16 | USN-8664-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1015.15 | USN-8618-1 |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-28.28.1 | — |
| Ubuntu 24.04 LTS | linux +44 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-azure-7.0 | 7.0.0-1014.14~24.04.1 | USN-8728-2 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1013.13~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gcp-7.0 +1 | 7.0.0-1011.11~24.04.1 | USN-8728-3, USN-8728-1 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-28.28~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-nvidia-7.0 | 7.0.0-1016.16~24.04.1 | USN-8663-1 |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-28.28.1~24.04.3 | — |
| Ubuntu 22.04 LTS | linux +59 | No fix yet | — |
Show 18 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-realtime +3 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime +2 | No fix yet | — |
| 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-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips +3 | No fix yet | — |
| 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 +21 | No fix yet | — |
| 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 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +5 | 6.4.0-150700.53.87.3 | SUSE-SU-2026:4935-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.87.3.150700.17.49.2 | SUSE-SU-2026:4935-1 |
| SLES 15 SP7 | kernel-obs-build | 6.4.0-150700.53.87.2 | SUSE-SU-2026:4935-1 |
| SLES 15 SP7 | kernel-syms | 6.4.0-150700.53.87.1 | SUSE-SU-2026:4935-1 |
| SLES 12 SP5 | kernel-syms +2 | 4.12.14-122.336.1 | SUSE-SU-2026:4892-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.39.1 | SUSE-SU-2026:24235-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24235-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.39.1 | SUSE-SU-2026:24235-1, SUSE-SU-2026:24197-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24235-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24184-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.39.1 | SUSE-SU-2026:24184-1, SUSE-SU-2026:24179-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-159998.54.1.159998.21.39 | SUSE-SU-2026:24379-1 |
| SLE Micro 6.1 | kernel-rt +4 | 6.4.0-159998.54.1 | SUSE-SU-2026:24553-1, SUSE-SU-2026:24379-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-159998.54.1.159998.21.40 | SUSE-SU-2026:24371-1 |
| SLE Micro 6.0 | kernel-rt +4 | 6.4.0-159998.54.1 | SUSE-SU-2026:24473-1, SUSE-SU-2026:24371-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.87.3 | SUSE-SU-2026:4935-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_22 | 1-150700.1.3.1 | SUSE-SU-2026:4940-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_23 | 1-150700.15.3.2 | SUSE-SU-2026:4935-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.336.1 | SUSE-SU-2026:4892-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_89 | 1-8.3.1 | SUSE-SU-2026:4892-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.81.1 | SUSE-SU-2026:4940-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.1 | kernel-default-base | 6.12.0-160100.9.1.160100.3.14 | openSUSE-SU-2026:22309-1 |
| openSUSE Leap 16.1 | kernel-nvidia64kb +2 | 6.12.0-160100.6.1 | openSUSE-SU-2026:22313-1 |
| openSUSE Leap 16.1 | kernel-rt +11 | 6.12.0-160100.9.1 | openSUSE-SU-2026:22309-1 |
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.25 | openSUSE-SU-2026:22091-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.39.1 | openSUSE-SU-2026:22091-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.94-123.174 | 1:1.0-0.amzn2023 | ALAS2023-2026-1968 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.94-123.174.amzn2023 | ALAS2023-2026-1968 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-206.104.3.3.el10uek | ELSA-2026-500248 |
Advisories 25
- openSUSE-SU-2026:22313-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 14, 2026
- openSUSE-SU-2026:22309-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 14, 2026
- USN-8593-1 linux-ibm, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8663-1 linux-nvidia, linux-nvidia-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-1 linux-gcp-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8618-1 linux-aws, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-3 linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-2 linux-azure-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8603-1 linux-azure, linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8664-1 linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- WID-SEC-2026-2403 Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:24553-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 7, 2026
- SUSE-SU-2026:24473-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 4, 2026
- SUSE-SU-2026:4940-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 31, 2026
- SUSE-SU-2026:4935-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 31, 2026
- SUSE-SU-2026:24379-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 27, 2026
- SUSE-SU-2026:24371-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 27, 2026
- SUSE-SU-2026:4892-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 24, 2026
- SUSE-SU-2026:24235-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 21, 2026
- SUSE-SU-2026:24197-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 21, 2026
- SUSE-SU-2026:24184-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- SUSE-SU-2026:24179-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- openSUSE-SU-2026:22091-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 19, 2026
- ELSA-2026-500248 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Sep 4, 2026
- ALAS2023-2026-1968 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 12, 2026