CVE-2024-35791: KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region()

Published May 17, 2024
·
Updated

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

KVM: SVM: Flush pages under kvm->lock to fix UAF in svmregisterencregion()

Do the cache flush of converted pages in svmregisterencregion() before dropping kvm->lock to fix use-after-free issues where region and/or its array of pages could be freed by a different task, e.g. if userspace has unregisterencregionlocked() already queued up for the region.

Note, the "obvious" alternative of using local variables doesn't fully resolve the bug, as region->pages is also dynamically allocated. I.e. the region structure itself would be fine, but region->pages could be freed.

Flushing multiple pages under kvm->lock is unfortunate, but the entire flow is a rare slow path, and the manual flush is only needed on CPUs that lack coherency for encrypted memory.

Other sources

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

KVM: SVM: Flush pages under kvm->lock to fix UAF in svmregisterencregion()

The Linux kernel CVE team has assigned CVE-2024-35791 to this issue.

Upstream advisory: https://lore.kernel.org/linux-cve-announce/2024051708-CVE-2024-35791-65ad@gregkh/T

— Red Hat

Affected Software

165 affected componentsFixes available
Linux Linux kernel>=4.19.176<4.20
Linux Linux kernel>=5.4.98<5.5
Linux Linux kernel>=5.10.15<5.10.215
Linux Linux kernel>=5.11.1<5.15.154
Linux Linux kernel>=5.16<6.1.84
Linux Linux kernel>=6.2<6.6.24
Linux Linux kernel>=6.7<6.7.12
Linux Linux kernel=5.11
Linux Linux kernel=5.11-rc7
Linux Linux kernel=6.8-rc1
Linux Linux kernel=6.8-rc2
Linux Linux kernel=6.8-rc3
Linux Linux kernel=6.8-rc4
Linux Linux kernel=6.8-rc5
Linux Linux kernel=6.8-rc6
Linux Linux kernel=6.8-rc7
Debian Debian Linux=10.0
debian/linux<6.1.85-1
6.1.85-1
debian/linux<6.7.12-1
6.7.12-1
debian/linux<6.7.12-1
6.7.12-1
debian/linux
6.1.176-16.1.190-16.12.107-16.12.115-27.2.12-17.2.15-1
redhat/kernel<5.10.215
5.10.215
redhat/kernel<5.15.154
5.15.154
redhat/kernel<6.1.84
6.1.84
redhat/kernel<6.6.24
6.6.24
redhat/kernel<6.7.12
6.7.12
redhat/kernel<6.8
6.8
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-aws-5.4*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-5.4*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gcp-5.4*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-5.4*
ubuntu/linux-ibm-5.4*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-oracle-5.4*
ubuntu/linux-raspi-5.4*
ubuntu/linux-aws-5.15<5.15.0-1065.71~20.04.1
5.15.0-1065.71~20.04.1
ubuntu/linux-azure-5.15<5.15.0-1068.77~20.04.1
5.15.0-1068.77~20.04.1
ubuntu/linux-gcp-5.15<5.15.0-1065.73~20.04.1
5.15.0-1065.73~20.04.1
ubuntu/linux-gkeop-5.15<5.15.0-1048.55~20.04.1
5.15.0-1048.55~20.04.1
ubuntu/linux-hwe-5.15<5.15.0-116.126~20.04.1
5.15.0-116.126~20.04.1
ubuntu/linux-ibm-5.15<5.15.0-1058.61~20.04.1
5.15.0-1058.61~20.04.1
ubuntu/linux-intel-iotg-5.15<5.15.0-1060.66~20.04.1
5.15.0-1060.66~20.04.1
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-116.126~20.04.1
5.15.0-116.126~20.04.1
ubuntu/linux-nvidia-tegra-5.15<5.15.0-1027.27~20.04.1
5.15.0-1027.27~20.04.1
ubuntu/linux-oracle-5.15<5.15.0-1063.69~20.04.1
5.15.0-1063.69~20.04.1
ubuntu/linux-riscv-5.15<5.15.0-1061.65~20.04.1
5.15.0-1061.65~20.04.1
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-bluefield*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm*
ubuntu/linux-intel-5.13*
ubuntu/linux-iot*
ubuntu/linux-kvm*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.8*
ubuntu/linux-xilinx-zynqmp*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-fips*
ubuntu/linux<5.15.0-116.126
5.15.0-116.126
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1065.71
5.15.0-1065.71
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-azure<5.15.0-1068.77
5.15.0-1068.77
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-fde<5.15.0-1068.77.1
5.15.0-1068.77.1
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-gcp<5.15.0-1064.72
5.15.0-1064.72
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gke<5.15.0-1062.68
5.15.0-1062.68
ubuntu/linux-gkeop<5.15.0-1048.55
5.15.0-1048.55
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm<5.15.0-1058.61
5.15.0-1058.61
ubuntu/linux-intel-iotg<5.15.0-1060.66
5.15.0-1060.66
ubuntu/linux-kvm<5.15.0-1062.67
5.15.0-1062.67
ubuntu/linux-lowlatency<5.15.0-116.126
5.15.0-116.126
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-nvidia<5.15.0-1060.61
5.15.0-1060.61
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-tegra<5.15.0-1026.26
5.15.0-1026.26
ubuntu/linux-nvidia-tegra-igx<5.15.0-1015.15
5.15.0-1015.15
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1063.69
5.15.0-1063.69
ubuntu/linux-oracle-6.5*
ubuntu/linux-raspi<5.15.0-1058.61
5.15.0-1058.61
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp<5.15.0-1035.39
5.15.0-1035.39
ubuntu/linux-bluefield<5.15.0-1047.49
5.15.0-1047.49
ubuntu/linux-intel-iot-realtime<5.15.0-1058.60
5.15.0-1058.60
ubuntu/linux-realtime<5.15.0-1066.74
5.15.0-1066.74
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips<5.15.0-1065.71+fips1
5.15.0-1065.71+fips1
ubuntu/linux-azure-fips<5.15.0-1068.77+fips1
5.15.0-1068.77+fips1
ubuntu/linux-fips<5.15.0-115.125+fips1
5.15.0-115.125+fips1
ubuntu/linux-gcp-fips<5.15.0-1064.72+fips1
5.15.0-1064.72+fips1
ubuntu/linux-raspi-realtime<6.8.0-2002.2
6.8.0-2002.2
ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.1.85-1
  2. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.7.12-1
  3. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1
  4. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 5.10.215
  5. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 5.15.154
  6. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 6.1.84
  7. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 6.6.24
  8. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 6.7.12
  9. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 6.8
  10. Upgrade

    Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1065.71~20.04.1
  11. Upgrade

    Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1068.77~20.04.1
  12. Upgrade

    Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1065.73~20.04.1
  13. Upgrade

    Upgrade ubuntu/linux-gkeop-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1048.55~20.04.1
  14. Upgrade

    Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-116.126~20.04.1
  15. Upgrade

    Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1058.61~20.04.1
  16. Upgrade

    Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1060.66~20.04.1
  17. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-116.126~20.04.1
  18. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1027.27~20.04.1
  19. Upgrade

    Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1063.69~20.04.1
  20. Upgrade

    Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1061.65~20.04.1
  21. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 5.15.0-116.126
  22. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 5.15.0-1065.71
  23. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 5.15.0-1068.77
  24. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 5.15.0-1068.77.1
  25. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1064.72
  26. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 5.15.0-1062.68
  27. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 5.15.0-1048.55
  28. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1058.61
  29. Upgrade

    Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.

    Fixed in 5.15.0-1060.66
  30. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1062.67
  31. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 5.15.0-116.126
  32. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 5.15.0-1060.61
  33. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 5.15.0-1026.26
  34. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.

    Fixed in 5.15.0-1015.15
  35. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 5.15.0-1063.69
  36. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 5.15.0-1058.61
  37. Upgrade

    Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1035.39
  38. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 5.15.0-1047.49
  39. Upgrade

    Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1058.60
  40. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1066.74
  41. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1065.71+fips1
  42. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1068.77+fips1
  43. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-115.125+fips1
  44. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1064.72+fips1
  45. Upgrade

    Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.0-2002.2
  46. Compensating control

    Apply the upstream fix described for KVM SVM by ensuring the cache flush of converted pages in svm_register_enc_region() is performed while holding kvm->lock, and only then drop kvm->lock, to prevent UAF where region and/or region->pages could be freed by a different task. (This corresponds to the change titled: “KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region()”.)

  47. Compensating control

    If patching is not immediately possible, mitigate by only relying on systems/CPUs that have coherency for encrypted memory, since the manual flush is only needed on CPUs that lack coherency for encrypted memory (per the description: “the manual flush is only needed on CPUs that lack coherency for encrypted memory”).

Event History

May 17, 2024
CVE Published
via MITRE·12:24 PM
Data Sourced
via MITRE·12:24 PM
DescriptionSeverity
Data Sourced
via OSV·01:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·01:15 PM
Description
Data Sourced
via Red Hat·09:02 PM
DescriptionSeverityAffected Software
Aug 4, 2026
Data Sourced
via NVD·11:17 AM
RemedySeverityWeaknessAffected Software

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2024-35791?

CVE-2024-35791 is classified as a medium severity vulnerability in the Linux kernel.

2

How do I fix CVE-2024-35791?

To fix CVE-2024-35791, upgrade your Linux kernel to the specified secure versions: 5.10.215, 5.15.154, 6.1.84, 6.6.24, 6.7.12, and 6.8, or the listed Debian kernel updates.

3

Which systems are impacted by CVE-2024-35791?

CVE-2024-35791 impacts various versions of the Linux kernel across multiple distributions including Red Hat and Debian.

4

What type of vulnerability is CVE-2024-35791?

CVE-2024-35791 is a use-after-free (UAF) vulnerability related to the KVM subsystem in the Linux kernel.

5

When was CVE-2024-35791 resolved?

CVE-2024-35791 was resolved with a patch provided in a kernel update shortly after its identification.

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