CVE-2021-47453

System crash via unallocated IDA free

Published May 22, 2024 · Updated May 11, 2026

A teardown flaw in the Linux kernel ice driver 5.14 through 5.14.14 allows local users to crash the system when the driver unloads. The remove path calls ida_free() for aux_idx even when that identifier was never allocated, corrupting IDA bookkeeping and triggering a kernel crash. The condition exists when the ice driver unloads on a system where RDMA support did not initialize the auxiliary index.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A teardown flaw in the Linux kernel ice driver 5.14 through 5.14.14 allows local users to crash the system when the driver unloads. The remove path calls ida_free() for aux_idx even when that identifier was never allocated, corrupting IDA bookkeeping and triggering a kernel crash. The condition exists when the ice driver unloads on a system where RDMA support did not initialize the auxiliary index.

The record

CVE
CVE-2021-47453
Published
May 22, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 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=5.14
  2. Affected versionversion=d25a0fc41c1f927bb914e72a03c1898052557406 <73e30a62b19b9fbb4e6a3465c59da186630d5f2e
  3. Affected versionversion=d25a0fc41c1f927bb914e72a03c1898052557406 <777682e59840e24e6c5672197e6ffbcf4bff823b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.14; version=d25a0fc41c1f927bb914e72a03c1898052557406 <73e30a62b19b9fbb4e6a3465c59da186630d5f2e; version=d25a0fc41c1f927bb914e72a03c1898052557406 <777682e59840e24e6c5672197e6ffbcf4bff823b

Published CVSS scores

5.5NVDCVSS: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

CWE-401Missing Release of Memory after Effective Lifetime
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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