CVE-2024-26999

Kernel crash via recursive serial-console spinlock

Published May 1, 2024 · Updated May 11, 2026

Improper locking in the Linux pmac_zilog serial driver allows local users to crash the kernel or disable serial reception. Error logging in pmz_receive_chars calls pmz_console_write while pmz_interrupt already holds the uart_port spinlock, causing recursive locking. The path requires pmac_zilog to serve as the serial console; CONFIG_DEBUG_SPINLOCK makes the recursion fatal, while other configurations lose receive service.

CVSS severity5.5
Medium
EPSS probability0.18%
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 pmac_zilog serial driver allows local users to crash the kernel or disable serial reception. Error logging in pmz_receive_chars calls pmz_console_write while pmz_interrupt already holds the uart_port spinlock, causing recursive locking. The path requires pmac_zilog to serve as the serial console; CONFIG_DEBUG_SPINLOCK makes the recursion fatal, while other configurations lose receive service.

The record

CVE
CVE-2024-26999
Published
May 1, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1be3226445362bfbf461c92a5bcdb1723f2e4907
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <52aaf1ff14622a04148dbb9ccce6d9de5d534ea7
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69a02273e288011b521ee7c1f3ab2c23fda633ce
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7a3bbe41efa55323b6ea3c35fa15941d4dbecdef
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ab86cf6f8d24e63e9aca23da5108af1aa5483928
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bbaafbb4651fede8d3c3881601ecaa4f834f9d3f
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ca09dfc3cfdf89e6af3ac24e1c6c0be5c575a729
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d679c816929d62af51c8e6d7fc0e165c9412d2f3
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1be3226445362bfbf461c92a5bcdb1723f2e4907; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <52aaf1ff14622a04148dbb9ccce6d9de5d534ea7; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69a02273e288011b521ee7c1f3ab2c23fda633ce; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7a3bbe41efa55323b6ea3c35fa15941d4dbecdef; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ab86cf6f8d24e63e9aca23da5108af1aa5483928; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bbaafbb4651fede8d3c3881601ecaa4f834f9d3f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ca09dfc3cfdf89e6af3ac24e1c6c0be5c575a729; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d679c816929d62af51c8e6d7fc0e165c9412d2f3; version=2.6.12

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-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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