CVE-2021-47151

Kernel resource exhaustion via device-node reference leak

Published Mar 25, 2024 · Updated May 11, 2026

Reference leak in the Qualcomm BCM voter driver in Linux allows local users to exhaust kernel memory through repeated device-tree lookups. The of_bcm_voter_get() function obtains a device-node reference with of_parse_phandle() but returns the matched voter without releasing that reference. Reachability requires a Qualcomm platform using the BCM voter device-tree binding and local ability to trigger repeated voter lookups; the resulting consequence is limited to availability.

CVSS severity5.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reference leak in the Qualcomm BCM voter driver in Linux allows local users to exhaust kernel memory through repeated device-tree lookups. The of_bcm_voter_get() function obtains a device-node reference with of_parse_phandle() but returns the matched voter without releasing that reference. Reachability requires a Qualcomm platform using the BCM voter device-tree binding and local ability to trigger repeated voter lookups; the resulting consequence is limited to availability.

The record

CVE
CVE-2021-47151
Published
Mar 25, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 25, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=5.7
  2. Affected versionversion=976daac4a1c581e5d5fd64047519fd6fcde39738 <4e3cea8035b6f1b9055e69cc6ebf9fa4e50763ae
  3. Affected versionversion=976daac4a1c581e5d5fd64047519fd6fcde39738 <93d1dbe7043b3c9492bdf396b2e98a008435b55b
  4. Affected versionversion=976daac4a1c581e5d5fd64047519fd6fcde39738 <a00593737f8bac2c9e97b696e7ff84a4446653e8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.7; version=976daac4a1c581e5d5fd64047519fd6fcde39738 <4e3cea8035b6f1b9055e69cc6ebf9fa4e50763ae; version=976daac4a1c581e5d5fd64047519fd6fcde39738 <93d1dbe7043b3c9492bdf396b2e98a008435b55b; version=976daac4a1c581e5d5fd64047519fd6fcde39738 <a00593737f8bac2c9e97b696e7ff84a4446653e8

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

T1499.004Application or System Exploitation

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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