CVE-2024-56739

Soft lockup via unchecked RTC read failure

Published Dec 29, 2024 · Updated May 11, 2026

Use of uninitialized data in the Linux RTC timer work queue allows local users to cause a kernel soft lockup after an RTC read failure. rtc_timer_do_work ignores a failed __rtc_read_time call and passes an uninitialized or invalid rtc_time value to rtc_tm_to_ktime, which can produce KTIME_MAX. Reachability requires a failed or invalid RTC time read and periodic timers in the timer queue; the resulting continual expiration can stall kernel processing.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized data in the Linux RTC timer work queue allows local users to cause a kernel soft lockup after an RTC read failure. rtc_timer_do_work ignores a failed __rtc_read_time call and passes an uninitialized or invalid rtc_time value to rtc_tm_to_ktime, which can produce KTIME_MAX. Reachability requires a failed or invalid RTC time read and periodic timers in the timer queue; the resulting continual expiration can stall kernel processing.

The record

CVE
CVE-2024-56739
Published
Dec 29, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 29, 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=2.6.38
  2. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <0d68e8514d9040108ff7d1b37ca71096674b6efe
  3. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <246f621d363988e7040f4546d20203dc713fa3e1
  4. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <39ad0a1ae17b54509cd9e93dcd8cec16e7c12d3f
  5. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <44b3257ff705d63d5f00ef8ed314a0eeb7ec37f2
  6. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <a1f0b4af90cc18b10261ecde56c6a56b22c75bd1
  7. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <dd4b1cbcc916fad5d10c2662b62def9f05e453d4
  8. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <e77bce0a8c3989b4173c36f4195122bca8f4a3e1
  9. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <e8ba8a2bc4f60a1065f23d6a0e7cbea945a0f40d
  10. Affected versionversion=6610e0893b8bc6f59b14fed7f089c5997f035f88 <fde56535505dde3336df438e949ef4742b6d6d6e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.38; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <0d68e8514d9040108ff7d1b37ca71096674b6efe; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <246f621d363988e7040f4546d20203dc713fa3e1; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <39ad0a1ae17b54509cd9e93dcd8cec16e7c12d3f; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <44b3257ff705d63d5f00ef8ed314a0eeb7ec37f2; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <a1f0b4af90cc18b10261ecde56c6a56b22c75bd1; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <dd4b1cbcc916fad5d10c2662b62def9f05e453d4; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <e77bce0a8c3989b4173c36f4195122bca8f4a3e1; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <e8ba8a2bc4f60a1065f23d6a0e7cbea945a0f40d; version=6610e0893b8bc6f59b14fed7f089c5997f035f88 <fde56535505dde3336df438e949ef4742b6d6d6e

Published CVSS scores

5.5OracleCVSS: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

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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

No sourced classifications are available.

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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