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NVD / CVE Program· CNA Linux

CVE-2021-47623: powerpc/fixmap: Fix VM debug warning on unmap

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.22% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 033fd42c18d9b2121595b6f1e8419a115f9ac5b7, 43ae0ccc4d2722b833fb59b905af129428e06d03, 67baac10dd5ad1e9f50e8f2659984b3b0728d54e.

Low priority for now. Upgrade to Linux Linux 033fd42c18d9b2121595b6f1e8419a115f9ac5b7, 43ae0ccc4d2722b833fb59b905af129428e06d03, 67baac10dd5ad1e9f50e8f2659984b3b0728d54e or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 16, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 13th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-47623

When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernelbefore 5.10.101
  • linux linux kernel5.11 and later · before 5.15.24
  • linux linux kernel5.16 and later · before 5.16.10
  • linux linux kernel5.17

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.5affected
    • 265c3491c4bc8d40587996d6ee2f447a7ccfb4f3 and later · before 67baac10dd5ad1e9f50e8f2659984b3b0728d54eaffected · git
    • 265c3491c4bc8d40587996d6ee2f447a7ccfb4f3 and later · before 43ae0ccc4d2722b833fb59b905af129428e06d03affected · git
    • 265c3491c4bc8d40587996d6ee2f447a7ccfb4f3 and later · before 033fd42c18d9b2121595b6f1e8419a115f9ac5b7affected · git
    • 265c3491c4bc8d40587996d6ee2f447a7ccfb4f3 and later · before aec982603aa8cc0a21143681feb5f60ecc69d718affected · git
    • before 5.5not affected · semver
    • 5.10.101 and later · up to and including 5.10.*not affected · semver
    • 5.15.24 and later · up to and including 5.15.*not affected · semver
    • 5.16.10 and later · up to and including 5.16.*not affected · semver
    • 5.17 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.16.10-15.16.10-1
openSUSE:Leap 15.5kernel-azurebefore 5.14.21-150500.33.63.15.14.21-150500.33.63.1
openSUSE:Leap 15.5kernel-rt_debugbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
openSUSE:Leap 15.5kernel-source-azurebefore 5.14.21-150500.33.63.15.14.21-150500.33.63.1
openSUSE:Leap 15.5kernel-source-rtbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
openSUSE:Leap 15.5kernel-syms-azurebefore 5.14.21-150500.33.63.15.14.21-150500.33.63.1
openSUSE:Leap 15.5kernel-syms-rtbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
openSUSE:Leap Micro 5.5kernel-rtbefore 5.14.21-150500.13.64.15.14.21-150500.13.64.1
Red Hat:rhel_e4s:9.0::appstreambpftool-debuginfobefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debug-debuginfobefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debug-develbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debug-devel-matchedbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debuginfobefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debuginfo-common-aarch64before 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debuginfo-common-ppc64lebefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debuginfo-common-s390xbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-debuginfo-common-x86_64before 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-develbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-devel-matchedbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-docbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-tools-debuginfobefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-zfcpdump-debuginfobefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-zfcpdump-develbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0
Red Hat:rhel_e4s:9.0::appstreamkernel-zfcpdump-devel-matchedbefore 0:5.14.0-70.117.1.el9_00:5.14.0-70.117.1.el9_0

+28

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2024-41008Jul 16, 2024 · drm/amdgpu: change vm->task_info handling
    22Monitor
  • ← EarlierCVE-2021-47622Jul 16, 2024 · scsi: ufs: Fix a deadlock in the error handler
    22Monitor
  • Later →CVE-2021-47624Jul 16, 2024 · net/sunrpc: fix reference count leaks in rpc_sysfs_xprt_state_change
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux033fd42c18d9b2121595b6f1e8419a115f9ac5b7Vendor (CNA)
Linux Linux43ae0ccc4d2722b833fb59b905af129428e06d03Vendor (CNA)
Linux Linux67baac10dd5ad1e9f50e8f2659984b3b0728d54eVendor (CNA)
Linux Linuxaec982603aa8cc0a21143681feb5f60ecc69d718Vendor (CNA)
debian:linux5.16.10-1 · Debian:12Package registry (OSV)
opensuse:kernel-azure5.14.21-150500.33.63.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-rt5.14.21-150500.13.64.1 · openSUSE:Leap Micro 5.5Package registry (OSV)
opensuse:kernel-rt_debug5.14.21-150500.13.64.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-source-azure5.14.21-150500.33.63.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-source-rt5.14.21-150500.13.64.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-syms-azure5.14.21-150500.33.63.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-syms-rt5.14.21-150500.13.64.1 · openSUSE:Leap 15.5Package registry (OSV)
red hat:bpftool-debuginfo0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-s390x0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-x86_640:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-devel0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-devel-matched0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
red hat:kernel-doc0:5.14.0-70.117.1.el9_0 · Red Hat:rhel_e4s:9.0::appstreamPackage registry (OSV)
suse:kernel-azure5.14.21-150500.33.63.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5Package registry (OSV)
suse:kernel-livepatch-SLE15-SP5-RT_Update_181-150500.11.3.1 · SUSE:Linux Enterprise Live Patching 15 SP5Package registry (OSV)
suse:kernel-rt5.14.21-150500.13.64.1 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)
suse:kernel-rt_debug5.14.21-150500.13.64.1 · SUSE:Real Time Module 15 SP5Package registry (OSV)
suse:kernel-source-azure5.14.21-150500.33.63.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5Package registry (OSV)
suse:kernel-source-rt5.14.21-150500.13.64.1 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)

+2

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records