Description
In the Linux kernel, the following vulnerability has been resolved:
vmxnet3: Fix malformed packet sizing in vmxnet3_process_xdp
vmxnet3 driver's XDP handling is buggy for packet sizes using ring0 (that
is, packet sizes between 128 - 3k bytes).
We noticed MTU-related connectivity issues with Cilium's service load-
balancing in case of vmxnet3 as NIC underneath. A simple curl to a HTTP
backend service where the XDP LB was doing IPIP encap led to overly large
packet sizes but only for *some* of the packets (e.g. HTTP GET request)
while others (e.g. the prior TCP 3WHS) looked completely fine on the wire.
In fact, the pcap recording on the backend node actually revealed that the
node with the XDP LB was leaking uninitialized kernel data onto the wire
for the affected packets, for example, while the packets should have been
152 bytes their actual size was 1482 bytes, so the remainder after 152 bytes
was padded with whatever other data was in that page at the time (e.g. we
saw user/payload data from prior processed packets).
We only noticed this through an MTU issue, e.g. when the XDP LB node and
the backend node both had the same MTU (e.g. 1500) then the curl request
got dropped on the backend node's NIC given the packet was too large even
though the IPIP-encapped packet normally would never even come close to
the MTU limit. Lowering the MTU on the XDP LB (e.g. 1480) allowed to let
the curl request succeed (which also indicates that the kernel ignored the
padding, and thus the issue wasn't very user-visible).
Commit e127ce7699c1 ("vmxnet3: Fix missing reserved tailroom") was too eager
to also switch xdp_prepare_buff() from rcd->len to rbi->len. It really needs
to stick to rcd->len which is the actual packet length from the descriptor.
The latter we also feed into vmxnet3_process_xdp_small(), by the way, and
it indicates the correct length needed to initialize the xdp->{data,data_end}
parts. For e127ce7699c1 ("vmxnet3: Fix missing reserved tailroom") the
relevant part was adapting xdp_init_buff() to address the warning given the
xdp_data_hard_end() depends on xdp->frame_sz. With that fixed, traffic on
the wire looks good again.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.6.23 – < 6.6.89, 6.7.11 – < 6.8, 6.8.2 – < 6.9, 6.9 | 6.6.89 |
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 | 6.12.27-1 | — |
| Debian 13 | linux | 6.12.27-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1016.20 | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.04 | linux | 6.14.0-22.22 | USN-7594-1 |
| Ubuntu 25.04 | linux-aws +3 | 6.14.0-1007.7 | USN-7594-3, USN-7594-2, USN-7594-1 |
| Ubuntu 25.04 | linux-gcp | 6.14.0-1008.8 | USN-7594-1 |
| Ubuntu 25.04 | linux-realtime | 6.14.0-1004.4 | USN-7594-1 |
| 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-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-gcp | 6.8.0-1047.50 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gcp-6.14 | 6.14.0-1011.11~24.04.1 | — |
| 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-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-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-xilinx | 6.8.0-1023.24 | USN-8052-2 |
| 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-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1046.53~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1047.50~22.04.2 | USN-8031-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-100.100~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1044.44~22.04.1 | USN-8028-8 |
| 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-oracle-6.8 | 6.8.0-1043.44~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
Show 6 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 | 6.8.0-2037.38 | 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 | 6.14.0-1010.10~24.04.1 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1041.42~22.04.1 | USN-8028-2 |
| Ubuntu Pro FIPS-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 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | rv +77 | 6.12.0-55.20.1.el10_0 | RHSA-2025:10371 |
| RHEL 9 | kpatch-patch-5_14_0-570_17_1 | 1-3.el9_6 | RHSA-2025:10674 |
| RHEL 9 | rv +77 | 5.14.0-570.25.1.el9_6 | RHSA-2025:10379 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | kernel-doc +1 | 6.12.0-55.20.1.el10_0 | ALSA-2025:10371 |
| AlmaLinux 9 | rv +75 | 5.14.0-570.25.1.el9_6 | ALSA-2025:10379 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | kernel | 6.12.0-55.20.1.el10_0 | RLSA-2025:10371 |
| Rocky Linux 9 | kernel | 5.14.0-570.25.1.el9_6 | RLSA-2025:10379 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.3.1 | SUSE-SU-2025:01951-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.3.1 | SUSE-SU-2025:01967-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.3.1.150700.17.2.1 | SUSE-SU-2025:01951-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.50.1 | SUSE-SU-2025:01614-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.37.1 | SUSE-SU-2025:01707-1 |
| SLES 15 SP6 | kernel-coco +3 | 6.4.0-15061.21.coco15sp6.1 | SUSE-SU-2025:01919-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.50.1.150600.12.22.1 | SUSE-SU-2025:01614-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.1 | kernel-default-base | 6.4.0-29.1.21.7 | SUSE-SU-2025:20354-1 |
| SLE Micro 6.1 | kernel-livepatch-MICRO-6-0_Update_7 +1 | 1-1.2 | SUSE-SU-2025:20355-1, SUSE-SU-2025:20354-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-31.1 | SUSE-SU-2025:20355-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-29.1 | SUSE-SU-2025:20354-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-29.1.21.7 | SUSE-SU-2025:20343-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0_Update_7 +1 | 1-1.2 | SUSE-SU-2025:20344-1, SUSE-SU-2025:20343-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-31.1 | SUSE-SU-2025:20344-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-29.1 | SUSE-SU-2025:20343-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.3.1 | SUSE-SU-2025:01951-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_1 | 1-150700.1.3.1 | SUSE-SU-2025:01972-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_1 | 1-150700.15.3.1 | SUSE-SU-2025:01951-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.50.1 | SUSE-SU-2025:01614-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_11 | 1-150600.1.3.2 | SUSE-SU-2025:01964-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_11 | 1-150600.13.3.1 | SUSE-SU-2025:01614-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +3 | 6.4.0-150700.7.3.1 | SUSE-SU-2025:01972-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.39.1 | SUSE-SU-2025:01964-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.50.1 | SUSE-SU-2025:01614-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.37.1 | SUSE-SU-2025:01707-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.50.1.150600.12.22.1 | SUSE-SU-2025:01614-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.39.1 | SUSE-SU-2025:01964-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | bpftool +14 | 6.12.29-33.102.amzn2023 | ALAS2023-2025-994 |
| Amazon Linux 2023 | kernel-livepatch-6.12.29-33.102 | 1.0-0.amzn2023 | ALAS2023-2025-994 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | rv +28 | 6.12.0-55.20.1.0.1.el10_0 | ELSA-2025-10371 |
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-101.33.4.3.el10uek | ELSA-2025-20530, ELSA-2025-20480 |
| Oracle Linux 9 | rv +28 | 5.14.0-570.25.1.0.1.el9_6 | ELSA-2025-10379 |
Advisories 43
- 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-8028-4 linux-aws-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-1 linux, linux-raspi 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-8028-2 linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-7 linux-nvidia-lowlatency 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
- ALSA-2025:10379 Important: kernel security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:10371 Important: kernel security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2025:10379 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- WID-SEC-2025-0932 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 22, 2026
- RHSA-2025:10674 Red Hat Security Advisory: kpatch-patch-5_14_0-570_17_1 security update Red Hat Security Advisories (RHSA) · Jul 30, 2026
- RHSA-2025:10371 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Jul 30, 2026
- SUSE-SU-2025:20343-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20344-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20354-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20355-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:01972-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:01614-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:01967-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:01919-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:01951-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:01964-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:01707-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- USN-7594-2 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- USN-7594-1 linux, linux-gcp, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- USN-7594-3 linux-aws, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- RLSA-2025:10379 Important: kernel security update Rocky Linux Security Advisories · Oct 4, 2025
- RLSA-2025:10371 Important: kernel security update Rocky Linux Security Advisories · Oct 3, 2025
- ALAS2023-2025-994 Important: kernel6.12 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-2025-20480 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 17, 2025
- ELSA-2025-10371 Important: kernel security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 8, 2025
- ELSA-2025-10379 Important: kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 7, 2025