Cloudanix VulnDB

CVE-2021-47228

None

CVSS

—

EPSS

0.2%

Published

May 21, 2024

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A kernel issue can make some secure virtual machines crash during startup on certain hardware setups.

Exploitation
Other
Attacker needs
None
Complexity
Theoretical
Impact
Denial Of Service
Component
OS kernel
Class
Misconfiguration
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

The kernel fails to mark EFI boot services data memory descriptors with the EFI_MEMORY_RUNTIME attribute as requiring encrypted mapping under SEV, resulting in general protection faults during early EFI variable access.

Why it matters to the business

AMD SEV-enabled systems may experience boot failures or kernel panics when EFI runtime reservations are present, increasing downtime risk for virtualized workloads though exploitation likelihood remains low.

How an attack unfolds

No active exploitation occurs; the condition triggers automatically at boot on affected SEV guests when drivers reserve EFI memory, manifesting as a non-canonical address fault in efi_mokvar_entry_next rather than an attacker-controlled sequence.

How to fix it

Apply the upstream fix expanding __ioremap_check_other() to treat EFI runtime reservations as encrypted, or upgrade to a Linux kernel containing commit x86/ioremap: Map EFI-reserved memory as encrypted for SEV.

How to confirm the fix worked

Confirm successful boot on SEV guests without EFI-related GPFs and verify the presence of the corrected __ioremap_check_other logic or updated kernel version string.

How to detect it

Review early boot logs and kernel panics for references to efi_mokvar_entry_next, EFI Variables Facility, or non-canonical address faults on SEV-enabled systems.

  • efi_mokvar_entry_next
  • EFI Variables Facility v0.08
  • general protection fault, probably for non-canonical address

What your security team should do

  • Prioritize kernel updates for SEV hosts given the boot-time impact
  • Test EFI variable handling in virtualization test environments after patching
  • Monitor EPSS and KEV status for any future changes in exploit maturity

The record

In the Linux kernel, the following vulnerability has been resolved: x86/ioremap: Map EFI-reserved memory as encrypted for SEV Some drivers require memory that is marked as EFI boot services data. In order for this memory to not be re-used by the kernel after ExitBootServices(), efi_mem_reserve() is used to preserve it by inserting a new EFI memory descriptor and marking it with the EFI_MEMORY_RUNTIME attribute. Under SEV, memory marked with the EFI_MEMORY_RUNTIME attribute needs to be mapped encrypted by Linux, otherwise the kernel might crash at boot like below: EFI Variables Facility v0.08 2004-May-17 general protection fault, probably for non-canonical address 0x3597688770a868b2: 0000 [#1] SMP NOPTI CPU: 13 PID: 1 Comm: swapper/0 Not tainted 5.12.4-2-default #1 openSUSE Tumbleweed Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:efi_mokvar_entry_next [...] Call Trace: efi_mokvar_sysfs_init ? efi_mokvar_table_init do_one_initcall ? __kmalloc kernel_init_freeable ? rest_init kernel_init ret_from_fork Expand the __ioremap_check_other() function to additionally check for this other type of boot data reserved at runtime and indicate that it should be mapped encrypted for an SEV guest. [ bp: Massage commit message. ]

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux 0 5.10.46-1
Debian:12 linux 0 5.10.46-1
Debian:13 linux 0 5.10.46-1
SUSE:Enterprise Storage 7.1 kernel-64kb 0 5.3.18-150300.59.164.1
SUSE:Enterprise Storage 7.1 kernel-default 0 5.3.18-150300.59.164.1
SUSE:Enterprise Storage 7.1 kernel-default-base 0 5.3.18-150300.59.164.1.150300.18.96.1
SUSE:Enterprise Storage 7.1 kernel-docs 0 5.3.18-150300.59.164.1
SUSE:Enterprise Storage 7.1 kernel-obs-build 0 5.3.18-150300.59.164.1
SUSE:Enterprise Storage 7.1 kernel-preempt 0 5.3.18-150300.59.164.1
SUSE:Enterprise Storage 7.1 kernel-source 0 5.3.18-150300.59.164.1
SUSE:Enterprise Storage 7.1 kernel-syms 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Availability Extension 15 SP3 kernel-default 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-64kb 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default-base 0 5.3.18-150300.59.164.1.150300.18.96.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-docs 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-obs-build 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-preempt 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-syms 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Live Patching 15 SP3 kernel-default 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Live Patching 15 SP3 kernel-livepatch-SLE15-SP3_Update_45 0 1-150300.7.3.1
SUSE:Linux Enterprise Micro 5.1 kernel-default 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Micro 5.1 kernel-default-base 0 5.3.18-150300.59.164.1.150300.18.96.1
SUSE:Linux Enterprise Micro 5.1 kernel-rt 0 5.3.18-150300.172.1
SUSE:Linux Enterprise Micro 5.1 kernel-source-rt 0 5.3.18-150300.172.1
SUSE:Linux Enterprise Micro 5.2 kernel-default 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Micro 5.2 kernel-default-base 0 5.3.18-150300.59.164.1.150300.18.96.1
SUSE:Linux Enterprise Micro 5.2 kernel-rt 0 5.3.18-150300.172.1
SUSE:Linux Enterprise Micro 5.2 kernel-source-rt 0 5.3.18-150300.172.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-64kb 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-default 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-default-base 0 5.3.18-150300.59.164.1.150300.18.96.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-docs 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-obs-build 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-preempt 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-source 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-syms 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server 15 SP3-LTSS kernel-zfcpdump 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server for SAP Applications 15 SP3 kernel-default 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server for SAP Applications 15 SP3 kernel-default-base 0 5.3.18-150300.59.164.1.150300.18.96.1
SUSE:Linux Enterprise Server for SAP Applications 15 SP3 kernel-docs 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server for SAP Applications 15 SP3 kernel-obs-build 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server for SAP Applications 15 SP3 kernel-preempt 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server for SAP Applications 15 SP3 kernel-source 0 5.3.18-150300.59.164.1
SUSE:Linux Enterprise Server for SAP Applications 15 SP3 kernel-syms 0 5.3.18-150300.59.164.1
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-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 5.4.0-1063.66~18.04.1
Ubuntu:18.04:LTS linux-azure 0 No fix
Ubuntu:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure-5.4 0 5.4.0-1067.70~18.04.1
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-5.3 0 No fix
Ubuntu:18.04:LTS linux-gcp-5.4 0 5.4.0-1060.64~18.04.1
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 5.4.0-94.106~18.04.1
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 5.4.0-1012.13~18.04.1
Ubuntu:18.04:LTS linux-oem 0 No fix
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 5.4.0-1061.65~18.04.1
Ubuntu:18.04:LTS linux-raspi-5.4 0 5.4.0-1050.56~18.04.1
Ubuntu:20.04:LTS linux 0 No fix
Ubuntu:20.04:LTS linux 0 5.4.0-94.106
Ubuntu:20.04:LTS linux-aws 0 No fix
Ubuntu:20.04:LTS linux-aws 0 5.4.0-1063.66
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 5.15.0-1014.18~20.04.1
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 No fix
Ubuntu:20.04:LTS linux-azure 0 5.4.0-1067.70
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 5.15.0-1007.8~20.04.1
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 5.15.0-1019.24~20.04.1.1
Ubuntu:20.04:LTS linux-bluefield 0 No fix
Ubuntu:20.04:LTS linux-bluefield 0 5.4.0-1025.28
Ubuntu:20.04:LTS linux-gcp 0 No fix
Ubuntu:20.04:LTS linux-gcp 0 5.4.0-1060.64
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 5.15.0-1006.9~20.04.1
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 No fix
Ubuntu:20.04:LTS linux-gkeop 0 5.4.0-1031.32
Ubuntu:20.04:LTS linux-gkeop-5.15 0 5.15.0-1003.5~20.04.2
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 5.15.0-33.34~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 5.4.0-1012.13
Ubuntu:20.04:LTS linux-ibm-5.15 0 5.15.0-1033.36~20.04.1
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 5.15.0-1003.5~20.04.1
Ubuntu:20.04:LTS linux-iot 0 5.4.0-1001.3
Ubuntu:20.04:LTS linux-kvm 0 No fix
Ubuntu:20.04:LTS linux-kvm 0 5.4.0-1053.55
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 5.15.0-33.34~20.04.1
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 No fix
Ubuntu:20.04:LTS linux-oracle 0 5.4.0-1061.65
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 5.15.0-1007.9~20.04.1
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 5.4.0-1050.56
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 5.15.0-1015.17~20.04.1
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 5.13.0-19.19
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 5.13.0-1005.6
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 6.5.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-aws-6.8 0 6.8.0-1009.9~22.04.2
Ubuntu:22.04:LTS linux-azure 0 5.13.0-1006.7
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 6.5.0-1007.7~22.04.1
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 5.15.0-1019.24.1
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-gcp 0 5.13.0-1005.6
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 6.5.0-1010.10~22.04.3
Ubuntu:22.04:LTS linux-gcp-6.8 0 6.8.0-1010.11~22.04.1
Ubuntu:22.04:LTS linux-gke 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-gkeop 0 5.15.0-1001.2
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 6.5.0-14.14~22.04.1
Ubuntu:22.04:LTS linux-hwe-6.8 0 6.8.0-38.38~22.04.1
Ubuntu:22.04:LTS linux-ibm 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 No fix
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 5.15.0-1021.26
Ubuntu:22.04:LTS linux-intel-iotg 0 5.15.0-1004.6
Ubuntu:22.04:LTS linux-kvm 0 5.13.0-1004.4
Ubuntu:22.04:LTS linux-lowlatency 0 5.15.0-22.22
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 6.5.0-14.14.1~22.04.1
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 5.15.0-1005.5
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 6.5.0-1004.4
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1008.8~22.04.1
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 6.5.0-1003.3
Ubuntu:22.04:LTS linux-oracle 0 5.13.0-1008.10
Ubuntu:22.04:LTS linux-oracle-6.5 0 6.5.0-1013.13~22.04.4
Ubuntu:22.04:LTS linux-oracle-6.8 0 6.8.0-1006.6~22.04.3
Ubuntu:22.04:LTS linux-raspi 0 5.13.0-1008.9
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 6.5.0-17.17.1.1~22.04.1
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
Ubuntu:22.04:LTS linux-starfive-6.2 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.5 0 6.5.0-1007.8~22.04.1
Ubuntu:22.04:LTS linux-xilinx-zynqmp 0 5.15.0-1022.26
Ubuntu:22.04:LTS:for:NVIDIA:BlueField linux-bluefield 0 5.15.0-1011.13
Ubuntu:24.04:LTS linux 0 6.5.0-9.9

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