Skip to content
OpenAdvisories
Unscored CVE-2026-23057 EUVD-2026-5487GHSA-2725-mxxg-w826

vsock/virtio: Coalesce only linear skb

Published Feb 4, 2026 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-lowlatency Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

vsock/virtio: Coalesce only linear skb

vsock/virtio common tries to coalesce buffers in rx queue: if a linear skb
(with a spare tail room) is followed by a small skb (length limited by
GOOD_COPY_LEN = 128), an attempt is made to join them.

Since the introduction of MSG_ZEROCOPY support, assumption that a small skb
will always be linear is incorrect. In the zerocopy case, data is lost and
the linear skb is appended with uninitialized kernel memory.

Of all 3 supported virtio-based transports, only loopback-transport is
affected. G2H virtio-transport rx queue operates on explicitly linear skbs;
see virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G
vhost-transport may allocate non-linear skbs, but only for sizes that are
not considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in
virtio_vsock_alloc_skb().

Ensure only linear skbs are coalesced. Note that skb_tailroom(last_skb) > 0
guarantees last_skb is linear.

Affected products

VendorProductAffectedFixed
Linux Linux 6.7 6.12.68

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.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.18.8-1 —
Debian 13 linux 6.12.69-1 DSA-6126-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1022.26 —
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-aws-6.8 6.8.0-1057.60~22.04.1 —
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-6.8 6.8.0-1058.65~22.04.1 —
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1060.63~22.04.1 —
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-124.124~22.04.1 —
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1055.56~22.04.1 USN-8278-1
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-6.8 6.8.0-1054.57~22.04.1 USN-8289-2
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 20.04 LTS linux-gke +28 No fix yet —
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
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-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
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +7 6.4.0-150700.53.34.1 SUSE-SU-2026:1081-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.34.1.150700.17.23.1 SUSE-SU-2026:1081-1
Show 7 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +8 6.12.0-160000.27.1 SUSE-SU-2026:20931-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.27.1.160000.2.8 SUSE-SU-2026:20931-1
SLES 16.0 kernel-64kb +8 6.12.0-160000.27.1 SUSE-SU-2026:20931-1
SLES 16.0 kernel-default-base 6.12.0-160000.27.1.160000.2.8 SUSE-SU-2026:20931-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.27.1.160000.2.8 SUSE-SU-2026:20838-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.27.1 SUSE-SU-2026:20873-1, SUSE-SU-2026:20838-1
SLE Micro 6.1 kernel-default-base 6.4.0-40.1.21.17 SUSE-SU-2026:20667-1
SLE Micro 6.1 kernel-rt +4 6.4.0-40.1 SUSE-SU-2026:20876-1, SUSE-SU-2026:20667-1
SLE Micro 6.0 kernel-default-base 6.4.0-40.1.21.17 SUSE-SU-2026:20720-1
SLE Micro 6.0 kernel-rt +4 6.4.0-40.1 SUSE-SU-2026:20845-1, SUSE-SU-2026:20720-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.34.1 SUSE-SU-2026:1081-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_10 1-150700.1.3.1 SUSE-SU-2026:0962-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_10 1-150700.15.3.1 SUSE-SU-2026:1081-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.34.1 SUSE-SU-2026:0962-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.27.1.160000.2.8 openSUSE-SU-2026:20416-1
openSUSE Leap 16.0 kernel-rt +11 6.12.0-160000.27.1 openSUSE-SU-2026:20416-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.12.68-92.122 1:1.0-0.amzn2023 ALAS2023-2026-1455
Amazon Linux 2023 perf6.12 +14 1:6.12.68-92.122.amzn2023 ALAS2023-2026-1455

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-200.74.27.el10uek ELSA-2026-50372, ELSA-2026-50232, ELSA-2026-50160

Advisories 31

References