6.2

CVE-2021-47228: x86/ioremap: Map EFI-reserved memory as encrypted for SEV

Analyzed
AliasesUBUNTU-CVE-2021-47228DEBIAN-CVE-2021-47228
Published 21-05-2024Last modified 11-05-2026

Vulnerability summary

CVE-2021-47228 is a medium (CVSS 6.2) vulnerability in linux. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 14.8% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.2, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.2/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.24%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
SUSE-SU-2024:2010-1SUSE-SU-2024:2185-1

Timeline

  1. 21-05-2024
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

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. ]

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

15%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.24% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu87 products
  • linuxAll versions (No fix recorded) | < 5.4.0-94.106
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.4.0-1063.66
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < 208bb686e7fa7fff16e8fa78ff0db34aa9acdbd7 | ≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < b7a05aba39f733ec337c5b952e112dd2dc4fc404 | ≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < 8d651ee9c71bb12fc0c8eb2786b66cbe5aa3e43b | 5.10
  • linux_kernel≥ 5.10, < 5.10.46 | ≥ 5.11, < 5.12.13 | 5.13:rc1 | 5.13:rc2 | 5.13:rc3 | 5.13:rc4 | 5.13:rc5 | 5.13:rc6
Debian1 product
  • linux< 5.10.46-1

3 vendors · 90 products

References

7 links