CVE-2024-56531

Host soft lockup via synchronous USB teardown

Published Dec 27, 2024 · Updated Aug 5, 2026

Improper locking in the Linux kernel ALSA caiaq driver allows local users to cause a soft lockup by disconnecting an in-use USB device. The disconnect callback calls snd_card_free(), which waits for every open file descriptor and blocks upper-layer USB ioctls instead of deferring cleanup. Exploitation requires local access to an affected caiaq USB audio device with an open descriptor; the documented impact is a host soft lockup.

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

Improper locking in the Linux kernel ALSA caiaq driver allows local users to cause a soft lockup by disconnecting an in-use USB device. The disconnect callback calls snd_card_free(), which waits for every open file descriptor and blocks upper-layer USB ioctls instead of deferring cleanup. Exploitation requires local access to an affected caiaq USB audio device with an open descriptor; the documented impact is a host soft lockup.

The record

CVE
CVE-2024-56531
Published
Dec 27, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 27, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=2.6.22
  2. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <237f3faf0177bdde728fa3106d730d806436aa4d
  3. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <3993edf44d3df7b6e8c753eac6ac8783473fcbab
  4. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <4507a8b9b30344c5ddd8219945f446d47e966a6d
  5. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <4dd821dcbfcecf7af6a08370b0b217cde2818acf
  6. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <a3f9314752dbb6f6aa1f0f2b4c58243bda800738
  7. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <b04dcbb7f7b1908806b7dc22671cdbe78ff2b82c
  8. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <cadf1d8e9ddcd74584ec961aeac14ac549b261d8
  9. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <dd0de8cb708951cebf727aa045e8242ba651bb52
  10. Affected versionversion=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <ebad462eec93b0f701dfe4de98990e7355283801

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.22; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <237f3faf0177bdde728fa3106d730d806436aa4d; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <3993edf44d3df7b6e8c753eac6ac8783473fcbab; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <4507a8b9b30344c5ddd8219945f446d47e966a6d; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <4dd821dcbfcecf7af6a08370b0b217cde2818acf; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <a3f9314752dbb6f6aa1f0f2b4c58243bda800738; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <b04dcbb7f7b1908806b7dc22671cdbe78ff2b82c; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <cadf1d8e9ddcd74584ec961aeac14ac549b261d8; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <dd0de8cb708951cebf727aa045e8242ba651bb52; version=523f1dce37434a9a6623bf46e7893e2b4b10ac3c <ebad462eec93b0f701dfe4de98990e7355283801

Published CVSS scores

5.5CISA ADP VulnrichmentCVSS: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-667Improper Locking
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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