What is CVE-2021-47623?

CVE-2021-47623 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10. CVE-2021-47623 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47623?

CVE-2021-47623 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47623?

No patch is currently available for CVE-2021-47623. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-47623 actively exploited?

CVE-2021-47623 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2021-47623

Medium

In the Linux kernel, the following vulnerability has been resolved: powerpc/fixmap: Fix VM debug warning on unmap Unmapping a fixmap entry is done by calling __set_fixmap() with FIXMAP_PAGE_CLEAR as flags. Today, powerpc __set_fixmap() calls map_kernel_page(). map_kernel_page() is not happy when called a second time for the same page. WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8 CPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682 NIP: c0017cd4 LR: c00187f0 CTR: 00000010 REGS: e1011d50 TRAP: 0700 Not tainted (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 42000208 XER: 00000000 GPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c GPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 GPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000 NIP [c0017cd4] set_pte_at+0xc/0x1e8 LR [c00187f0] map_kernel_page+0x9c/0x100 Call Trace: [e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable) [e1011e30] [c0165fec] __set_fixmap+0x30/0x44 [e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170 [e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0 [e1011e90] [c0c03634] do_one_initcall+0x80/0x178 [e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250 [e1011f20] [c0007e34] kernel_init+0x24/0x140 [e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010 4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030 Implement unmap_kernel_page() which clears an existing pte.

Package Linux Kernel

Published 2024-07-16

Last modified 2025-10-03

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

The following references provide additional information about CVE-2021-47623 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7
Patch
Kernel patch commit
https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03
Patch
Kernel patch commit
https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2021-47623

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-07-16

Modified 2025-10-03

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-47623?

CVE-2021-47623 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . CVE-2021-47623 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47623?

CVE-2021-47623 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47623?

No patch is currently available for CVE-2021-47623. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-47623 actively exploited?

No — CVE-2021-47623 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.