Cloudanix VulnDB

CVE-2024-35804

Medium · 5.5

CVSS

5.5

EPSS

0.2%

Published

May 17, 2024

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A bug in the Linux kernel's virtual-machine support can cause guest memory to become corrupted when machines are moved between physical servers, potentially crashing applications or losing data.

Exploitation
Local Privilege
Attacker needs
Low Privilege
Complexity
Low
Impact
Data Tampering
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

KVM fails to mark the target guest frame number (gfn) as dirty after emulating an atomic instruction such as CMPXCHG, so the write to guest memory is not reported to userspace.

Why it matters to the business

Live migration of virtual machines can silently corrupt guest memory, leading to application crashes, data loss, or failed migrations that disrupt availability of virtualized workloads.

How an attack unfolds

An attacker with the ability to run code inside a KVM guest triggers an emulated atomic memory operation; during a subsequent live migration the hypervisor writes the result without logging the page as dirty, causing the destination to receive stale or inconsistent memory contents.

How to fix it

Upgrade the Linux kernel to a version containing commit 4b0986a3613c92f4ec1bdc7f60ec66fea135991f or later; rebuild and reboot all affected hosts.

How to confirm the fix worked

Verify the running kernel contains commit 4b0986a3613c92f4ec1bdc7f60ec66fea135991f; test live migration of a guest that performs atomic operations and confirm dirty pages are correctly reported to userspace.

Typical attack path

  1. Obtain code execution inside a KVM guest VM
  2. Execute an atomic instruction (CMPXCHG) that KVM must emulate
  3. Initiate or wait for a live migration of the VM
  4. KVM performs the write without dirty logging, resulting in memory corruption on the target host

How to detect it

Review kernel logs for KVM live-migration events around the time of guest instability; look for unexpected guest memory checksum mismatches or application crashes immediately after migration completes.

What your security team should do

  • Prioritize patching KVM hosts that perform live migration within the next maintenance window
  • Monitor kernel changelogs for backports of the fix to distribution kernels
  • Temporarily disable live migration on unpatched hosts if the workload allows

The record

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Mark target gfn of emulated atomic instruction as dirty When emulating an atomic access on behalf of the guest, mark the target gfn dirty if the CMPXCHG by KVM is attempted and doesn't fault. This fixes a bug where KVM effectively corrupts guest memory during live migration by writing to guest memory without informing userspace that the page is dirty. Marking the page dirty got unintentionally dropped when KVM's emulated CMPXCHG was converted to do a user access. Before that, KVM explicitly mapped the guest page into kernel memory, and marked the page dirty during the unmap phase. Mark the page dirty even if the CMPXCHG fails, as the old data is written back on failure, i.e. the page is still written. The value written is guaranteed to be the same because the operation is atomic, but KVM's ABI is that all writes are dirty logged regardless of the value written. And more importantly, that's what KVM did before the buggy commit. Huge kudos to the folks on the Cc list (and many others), who did all the actual work of triaging and debugging. base-commit: 6769ea8da8a93ed4630f1ce64df6aafcaabfce64

Affected packages

Ecosystem Package Introduced Fixed
Debian:12 linux 0 6.1.85-1
Debian:13 linux 0 6.7.12-1
Debian:14 linux 0 6.7.12-1
Linux Kernel 0 5.15.154
SUSE:Linux Enterprise High Availability Extension 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise High Availability Extension 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5-RT_Update_16 0 1-150500.11.3.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5_Update_15 0 1-150500.11.3.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_1 0 1-150600.1.5.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_1 0 1-150600.13.3.7
SUSE:Linux Enterprise Micro 5.5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Micro 5.5 kernel-default-base 0 5.14.21-150500.55.68.1.150500.6.31.1
SUSE:Linux Enterprise Micro 5.5 kernel-rt 0 5.14.21-150500.13.58.1
SUSE:Linux Enterprise Micro 5.5 kernel-source-rt 0 5.14.21-150500.13.58.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-64kb 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default-base 0 5.14.21-150500.55.68.1.150500.6.31.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-source 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-zfcpdump 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.7.3.150600.12.2.7
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.7.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-docs 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-obs-build 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-source 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-syms 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.7.4
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.7.2
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.7.1
SUSE:Linux Enterprise Module for Legacy 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-azure 0 5.14.21-150500.33.57.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure 0 5.14.21-150500.33.57.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-syms-azure 0 5.14.21-150500.33.57.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.5.4
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.5.4
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.5.1
SUSE:Linux Enterprise Workstation Extension 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Real Time Module 15 SP5 kernel-rt 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP5 kernel-rt_debug 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP5 kernel-source-rt 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP5 kernel-syms-rt 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP6 kernel-rt 0 6.4.0-150600.10.5.1
SUSE:Real Time Module 15 SP6 kernel-rt_debug 0 6.4.0-150600.10.5.1
SUSE:Real Time Module 15 SP6 kernel-source-rt 0 6.4.0-150600.10.5.1
SUSE:Real Time Module 15 SP6 kernel-syms-rt 0 6.4.0-150600.10.5.1
Ubuntu:14.04:LTS linux 0 3.11.0-12.19
Ubuntu:14.04:LTS linux-aws 0 4.4.0-1002.2
Ubuntu:14.04:LTS linux-azure 0 4.15.0-1023.24~14.04.1
Ubuntu:14.04:LTS linux-lts-xenial 0 4.4.0-13.29~14.04.1
Ubuntu:16.04:LTS linux 0 4.4.0-2.16
Ubuntu:16.04:LTS linux-aws 0 4.4.0-1001.10
Ubuntu:16.04:LTS linux-aws-hwe 0 4.15.0-1030.31~16.04.1
Ubuntu:16.04:LTS linux-azure 0 4.11.0-1009.9
Ubuntu:16.04:LTS linux-gcp 0 4.10.0-1004.4
Ubuntu:16.04:LTS linux-hwe 0 4.8.0-39.42~16.04.1
Ubuntu:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:16.04:LTS linux-kvm 0 4.4.0-1004.9
Ubuntu:16.04:LTS linux-oracle 0 4.15.0-1007.9~16.04.1
Ubuntu:18.04:LTS linux 0 4.13.0-16.19
Ubuntu:18.04:LTS linux-aws 0 4.15.0-1001.1
Ubuntu:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:18.04:LTS linux-aws-5.4 0 5.4.0-1018.18~18.04.1
Ubuntu:18.04:LTS linux-azure 0 No fix
Ubuntu:18.04:LTS linux-azure-4.15 0 4.15.0-1082.92
Ubuntu:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure-5.4 0 5.4.0-1020.20~18.04.1
Ubuntu:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:18.04:LTS linux-gcp 0 No fix
Ubuntu:18.04:LTS linux-gcp-4.15 0 4.15.0-1071.81
Ubuntu:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:18.04:LTS linux-gcp-5.4 0 5.4.0-1019.19~18.04.2
Ubuntu:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:18.04:LTS linux-hwe 0 No fix
Ubuntu:18.04:LTS linux-hwe-5.4 0 5.4.0-37.41~18.04.1
Ubuntu:18.04:LTS linux-hwe-edge 0 5.0.0-15.16~18.04.1
Ubuntu:18.04:LTS linux-ibm-5.4 0 5.4.0-1010.11~18.04.2
Ubuntu:18.04:LTS linux-kvm 0 4.15.0-1002.2
Ubuntu:18.04:LTS linux-oem 0 No fix
Ubuntu:18.04:LTS linux-oracle 0 4.15.0-1007.9
Ubuntu:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.4 0 5.4.0-1019.19~18.04.1
Ubuntu:18.04:LTS linux-raspi-5.4 0 5.4.0-1013.13~18.04.1
Ubuntu:20.04:LTS linux 0 5.4.0-9.12
Ubuntu:20.04:LTS linux-aws 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:20.04:LTS linux-aws-5.15 0 5.15.0-1065.71~20.04.1
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 5.4.0-1006.6
Ubuntu:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:20.04:LTS linux-azure-5.15 0 5.15.0-1068.77~20.04.1
Ubuntu:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:20.04:LTS linux-azure-fde-5.15 0 5.15.0-1068.77~20.04.1.1
Ubuntu:20.04:LTS linux-bluefield 0 5.4.0-1007.10
Ubuntu:20.04:LTS linux-gcp 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.15 0 5.15.0-1065.73~20.04.1
Ubuntu:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:20.04:LTS linux-gke 0 No fix
Ubuntu:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:20.04:LTS linux-gkeop 0 5.4.0-1008.9
Ubuntu:20.04:LTS linux-gkeop-5.15 0 5.15.0-1048.55~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.15 0 5.15.0-116.126~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 5.4.0-1003.4
Ubuntu:20.04:LTS linux-ibm-5.15 0 5.15.0-1058.61~20.04.1
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 5.15.0-1060.66~20.04.1
Ubuntu:20.04:LTS linux-iot 0 5.4.0-1001.3
Ubuntu:20.04:LTS linux-kvm 0 5.4.0-1004.4
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 5.15.0-116.126~20.04.1
Ubuntu:20.04:LTS linux-nvidia-tegra-5.15 0 5.15.0-1027.27~20.04.1
Ubuntu:20.04:LTS linux-oem-5.10 0 No fix
Ubuntu:20.04:LTS linux-oem-5.13 0 No fix
Ubuntu:20.04:LTS linux-oem-5.14 0 No fix
Ubuntu:20.04:LTS linux-oem-5.6 0 No fix
Ubuntu:20.04:LTS linux-oracle 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-oracle-5.11 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.13 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.15 0 5.15.0-1063.69~20.04.1
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 5.4.0-1007.7
Ubuntu:20.04:LTS linux-raspi2 0 No fix
Ubuntu:20.04:LTS linux-riscv 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.11 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.15 0 5.15.0-1061.65~20.04.1
Ubuntu:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 5.4.0-1020.24
Ubuntu:22.04:LTS linux 0 5.15.0-116.126
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 5.15.0-1065.71
Ubuntu:22.04:LTS linux-aws-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws-6.2 0 No fix
Ubuntu:22.04:LTS linux-aws-6.5 0 No fix
Ubuntu:22.04:LTS linux-aws-6.8 0 6.8.0-1009.9~22.04.2
Ubuntu:22.04:LTS linux-azure 0 5.15.0-1068.77
Ubuntu:22.04:LTS linux-azure-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-6.2 0 No fix
Ubuntu:22.04:LTS linux-azure-6.5 0 No fix
Ubuntu:22.04:LTS linux-azure-6.8 0 6.8.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-azure-fde 0 5.15.0-1068.77.1
Ubuntu:22.04:LTS linux-azure-fde-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-6.2 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-6.8 0 No fix
Ubuntu:22.04:LTS linux-gcp 0 5.15.0-1064.72
Ubuntu:22.04:LTS linux-gcp-5.19 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.5 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.8 0 6.8.0-1010.11~22.04.1
Ubuntu:22.04:LTS linux-gke 0 5.15.0-1062.68
Ubuntu:22.04:LTS linux-gkeop 0 5.15.0-1048.55
Ubuntu:22.04:LTS linux-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 6.8.0-38.38~22.04.1
Ubuntu:22.04:LTS linux-ibm 0 5.15.0-1058.61
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 No fix
Ubuntu:22.04:LTS linux-intel-iotg 0 5.15.0-1060.66
Ubuntu:22.04:LTS linux-kvm 0 5.15.0-1062.67
Ubuntu:22.04:LTS linux-lowlatency 0 5.15.0-116.126
Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 6.8.0-38.38.1~22.04.2
Ubuntu:22.04:LTS linux-nvidia 0 5.15.0-1060.61
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-nvidia-tegra 0 5.15.0-1026.26
Ubuntu:22.04:LTS linux-nvidia-tegra-igx 0 5.15.0-1015.15
Ubuntu:22.04:LTS linux-oem-5.17 0 No fix
Ubuntu:22.04:LTS linux-oem-6.0 0 No fix
Ubuntu:22.04:LTS linux-oem-6.1 0 No fix
Ubuntu:22.04:LTS linux-oem-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle 0 5.15.0-1063.69
Ubuntu:22.04:LTS linux-oracle-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle-6.8 0 6.8.0-1006.6~22.04.3
Ubuntu:22.04:LTS linux-raspi 0 5.15.0-1058.61
Ubuntu:22.04:LTS linux-realtime 0 No fix
Ubuntu:22.04:LTS linux-riscv 0 No fix
Ubuntu:22.04:LTS linux-riscv-5.19 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.5 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.8 0 6.8.0-38.38.1~22.04.1
Ubuntu:22.04:LTS linux-starfive-5.19 0 No fix

Related vulnerabilities