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High · 7.1 CVE-2026-45856 EUVD-2026-32322GHSA-xq3r-74hw-4c5p

RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send

Published May 27, 2026 · Updated Oct 19, 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-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 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-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 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-5.15 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-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 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-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 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-5.15 Package: linux-ibm-5.4 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 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-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx 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-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 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-5.4 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-5.15 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 Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send

ib_uverbs_post_send() uses cmd.wqe_size from userspace without any
validation before passing it to kmalloc() and using the allocated
buffer as struct ib_uverbs_send_wr.

If a user provides a small wqe_size value (e.g., 1), kmalloc() will
succeed, but subsequent accesses to user_wr->opcode, user_wr->num_sge,
and other fields will read beyond the allocated buffer, resulting in
an out-of-bounds read from kernel heap memory. This could potentially
leak sensitive kernel information to userspace.

Additionally, providing an excessively large wqe_size can trigger a
WARNING in the memory allocation path, as reported by syzkaller.

This is inconsistent with ib_uverbs_unmarshall_recv() which properly
validates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before
proceeding.

Add the same validation for ib_uverbs_post_send() to ensure wqe_size
is at least sizeof(struct ib_uverbs_send_wr).

Affected products

VendorProductAffectedFixed
Linux Linux 5.0 5.10.252

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 6.18.14-1 —
Debian 13 linux 6.12.85-1 —
Debian 12 linux 6.1.170-1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1026.30 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1096.98 —
Ubuntu 25.10 linux +8 No fix yet —
Ubuntu 24.04 LTS linux 6.8.0-134.134 USN-8492-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1060.63 USN-8492-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1063.71 USN-8606-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1062.69 USN-8607-1
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1039.42 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1063.69 USN-8492-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1058.64 USN-8492-2
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1045.48 USN-8492-2
Ubuntu 24.04 LTS linux-ibm 6.8.0-1060.61 USN-8492-1
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-134.134.1 USN-8497-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1058.61 USN-8492-1
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1058.61.1 USN-8492-2
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1029.30 USN-8498-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1057.58 USN-8492-1
Ubuntu 24.04 LTS linux-raspi 6.8.0-1060.64 USN-8492-4
Ubuntu 24.04 LTS linux-riscv +26 No fix yet —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1032.33 USN-8499-1
Ubuntu 22.04 LTS linux 5.15.0-186.196 USN-8575-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1112.119 USN-8575-2
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1060.63~22.04.1 USN-8492-2
Ubuntu 22.04 LTS linux-azure +1 5.15.0-1117.126 USN-8610-1, USN-8575-3
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1063.71~22.04.1 USN-8606-1
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1062.69~22.04.1 USN-8609-1
Ubuntu 22.04 LTS linux-gcp 5.15.0-1112.122 USN-8575-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1063.69~22.04.1 USN-8492-2
Ubuntu 22.04 LTS linux-gke 5.15.0-1108.114 USN-8575-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1095.103 USN-8575-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-136.136~22.04.1 USN-8619-1
Ubuntu 22.04 LTS linux-ibm 5.15.0-1106.110 USN-8575-2
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1060.61~22.04.1 USN-8492-2
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1107.113 USN-8620-4
Ubuntu 22.04 LTS linux-kvm 5.15.0-1104.109 USN-8575-1
Ubuntu 22.04 LTS linux-lowlatency 5.15.0-184.194 USN-8575-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-134.134.1~22.04.1 USN-8497-1
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1107.108 USN-8575-2
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1058.61~22.04.1 USN-8492-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1064.66 USN-8576-2
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1053.53 USN-8576-2
Ubuntu 22.04 LTS linux-oracle 5.15.0-1109.115 USN-8575-3
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1057.58~22.04.1 USN-8492-2
Ubuntu 22.04 LTS linux-raspi 5.15.0-1106.109 USN-8668-2
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 6.8.0-134.134~22.04.1 —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1075.79 USN-8575-1
Show 12 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
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 6.8.0-2049.50 USN-8492-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1055.56 USN-8492-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 +1 No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1104.106 USN-8620-3
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1111.120 USN-8575-1
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1055.56~22.04.1 USN-8492-1
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1060.63+fips1 USN-8492-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1062.69+fips1 USN-8492-5
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-134.134+fips1 USN-8492-5
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1063.69+fips1 USN-8492-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1112.119+fips1 USN-8575-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1117.126+fips1 USN-8620-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-186.196+fips1 USN-8575-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1112.122+fips1 USN-8575-1
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux +10 No fix yet —
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1112.119~20.04.1 USN-8575-2
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1117.126~20.04.1 USN-8620-1
Ubuntu Pro 20.04 LTS linux-azure-fde-5.15 5.15.0-1117.126~20.04.2 USN-8620-1
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1112.122~20.04.1 USN-8668-1
Ubuntu Pro 20.04 LTS linux-hwe-5.15 5.15.0-186.196~20.04.1 USN-8575-1
Ubuntu Pro 20.04 LTS linux-ibm-5.15 +1 5.15.0-1106.110~20.04.1 USN-8597-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1107.113~20.04.1 USN-8620-3
Ubuntu Pro 20.04 LTS linux-lowlatency-hwe-5.15 5.15.0-184.194~20.04.1 USN-8575-1
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1064.66~20.04.1 USN-8576-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1109.115~20.04.1 USN-8620-1
Ubuntu Pro 18.04 LTS linux-aws-5.4 +6 No fix yet —
ReleasePackageFixed inAdvisory
RHEL 9 rv +75 5.14.0-687.54.1.el9_8 RHSA-2026:74438
RHEL 8 kernel-rt +12 4.18.0-553.171.1.rt7.512.el8_10 RHSA-2026:75746
RHEL 8 perf +26 4.18.0-553.171.1.el8_10 RHSA-2026:75747

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 10 rv +74 6.12.0-211.63.1.el10_2 ALSA-2026:76738
AlmaLinux 9 rv +73 5.14.0-687.54.1.el9_8 ALSA-2026:74438
AlmaLinux 8 kernel-rt +9 4.18.0-553.171.1.rt7.512.el8_10 ALSA-2026:75746
AlmaLinux 8 perf +24 4.18.0-553.171.1.el8_10 ALSA-2026:75747

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 9 kernel 5.14.0-687.54.1.el9_8 RLSA-2026:74438
Rocky Linux 8 kernel 4.18.0-553.171.1.el8_10 RLSA-2026:75747
Rocky Linux 8 kernel-rt 4.18.0-553.171.1.rt7.512.el8_10 RLSA-2026:75746
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.60.1 SUSE-SU-2026:2482-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.60.1.150700.17.35.4 SUSE-SU-2026:2482-1
SLES 15 SP7 kernel-obs-build 6.4.0-150700.53.60.2 SUSE-SU-2026:2482-1
Show 7 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +8 6.12.0-160000.35.1 SUSE-SU-2026:22127-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.35.1.160000.2.16 SUSE-SU-2026:22127-1
SLES 16.0 kernel-64kb +8 6.12.0-160000.35.1 SUSE-SU-2026:22127-1, SUSE-SU-2026:22099-1
SLES 16.0 kernel-default-base 6.12.0-160000.35.1.160000.2.16 SUSE-SU-2026:22127-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.35.1.160000.2.16 SUSE-SU-2026:22112-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.35.1 SUSE-SU-2026:22117-1, SUSE-SU-2026:22112-1
SLE Micro 6.1 kernel-default-base 6.4.0-47.1.21.24 SUSE-SU-2026:22137-1
SLE Micro 6.1 kernel-rt +1 6.4.0-48.1 SUSE-SU-2026:22458-1
SLE Micro 6.1 kernel-source +2 6.4.0-47.1 SUSE-SU-2026:22137-1
SLE Micro 6.0 kernel-default-base 6.4.0-47.1.21.24 SUSE-SU-2026:22108-1
SLE Micro 6.0 kernel-rt +1 6.4.0-48.1 SUSE-SU-2026:22433-1
SLE Micro 6.0 kernel-source +2 6.4.0-47.1 SUSE-SU-2026:22108-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.60.1 SUSE-SU-2026:2482-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_16 1-150700.1.5.2 SUSE-SU-2026:2591-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_16 1-150700.15.3.2 SUSE-SU-2026:2482-1
SUSE Real Time Module 15 SP7 kernel-rt +1 6.4.0-150700.7.59.2 SUSE-SU-2026:2591-1
SUSE Real Time Module 15 SP7 kernel-syms-rt 6.4.0-150700.7.59.1 SUSE-SU-2026:2591-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.35.1.160000.2.16 openSUSE-SU-2026:20965-1
openSUSE Leap 16.0 kernel-rt +11 6.12.0-160000.35.1 openSUSE-SU-2026:20965-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.12.77-99.140 +2 1:1.0-0.amzn2023 ALAS2023-2026-1544, ALAS2023-2026-1543, ALAS2023-2026-1514
Amazon Linux 2023 perf +14 1:6.1.166-197.305.amzn2023 ALAS2023-2026-1544
Amazon Linux 2023 perf6.12 +14 1:6.12.77-99.140.amzn2023 ALAS2023-2026-1543
Amazon Linux 2023 perf6.18 +14 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 10 rv +29 6.12.0-211.63.1.el10_2 ELSA-2026-76738
Oracle Linux 9 kernel-uek +34 6.12.0-204.92.4.2.el10uek ELSA-2026-50372
Oracle Linux 9 rv +28 5.14.0-687.54.1.el9_8 ELSA-2026-74438
Oracle Linux 8 perf +19 4.18.0-553.171.1.el8_10 ELSA-2026-75747

Advisories 50

References