CVE-2021-47037

Kernel oops via consumed clock initialization state

Published Feb 28, 2024 · Updated May 11, 2026

Kernel driver reprobe failure in the Linux q6afe-clocks component allows local users to trigger a kernel oops after an APR restart. Static clock objects retain clk_hw.init pointers that the clock framework clears during initial registration, leaving a subsequent probe without valid initialization data. Reachability requires the Qualcomm q6afe audio-clock driver and an APR service restart, such as after a firmware crash; the resulting kernel oops interrupts the host.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Kernel driver reprobe failure in the Linux q6afe-clocks component allows local users to trigger a kernel oops after an APR restart. Static clock objects retain clk_hw.init pointers that the clock framework clears during initial registration, leaving a subsequent probe without valid initialization data. Reachability requires the Qualcomm q6afe audio-clock driver and an APR service restart, such as after a firmware crash; the resulting kernel oops interrupts the host.

The record

CVE
CVE-2021-47037
Published
Feb 28, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 28, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.10
  2. Affected versionversion=520a1c396d1966b64884d8e0176a580150d5a09e <2202e87fc19440cecfd4f7b4f60a7d48bc2e236c
  3. Affected versionversion=520a1c396d1966b64884d8e0176a580150d5a09e <62413972f5266568848a36fd15160397b211fa74
  4. Affected versionversion=520a1c396d1966b64884d8e0176a580150d5a09e <6893df3753beafa5f7351228a9dd8157a57d7492
  5. Affected versionversion=520a1c396d1966b64884d8e0176a580150d5a09e <96fadf7e8ff49fdb74754801228942b67c3eeebd

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=520a1c396d1966b64884d8e0176a580150d5a09e <2202e87fc19440cecfd4f7b4f60a7d48bc2e236c; version=520a1c396d1966b64884d8e0176a580150d5a09e <62413972f5266568848a36fd15160397b211fa74; version=520a1c396d1966b64884d8e0176a580150d5a09e <6893df3753beafa5f7351228a9dd8157a57d7492; version=520a1c396d1966b64884d8e0176a580150d5a09e <96fadf7e8ff49fdb74754801228942b67c3eeebd

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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