Service interruption via unreleased CacheFiles credentials
Published Apr 17, 2024 · Updated May 11, 2026
Memory leak in the Linux kernel CacheFiles subsystem allows local users to exhaust kernel memory by unbinding /dev/cachefiles. The cachefiles_add_cache error branch and cachefiles_daemon_unbind omit put_cred calls for cache_cred, leaving credential objects referenced after failure or unbind. Local access to the CacheFiles control device is required; repeating the affected lifecycle consumes unreclaimed kernel memory and interrupts service when memory is exhausted.
Summary
What happened
Memory leak in the Linux kernel CacheFiles subsystem allows local users to exhaust kernel memory by unbinding /dev/cachefiles. The cachefiles_add_cache error branch and cachefiles_daemon_unbind omit put_cred calls for cache_cred, leaving credential objects referenced after failure or unbind. Local access to the CacheFiles control device is required; repeating the affected lifecycle consumes unreclaimed kernel memory and interrupts service when memory is exhausted.
The record
- CVE
- CVE-2024-26840
- Published
- Apr 17, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-401, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 17, 2024CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=2.6.30
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <037d5a949b0455540ef9aab34c10ddf54b65d285
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <38e921616320d159336b0ffadb09e9fb4945c7c3
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <43eccc5823732ba6daab2511ed32dfc545a666d8
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <8b218e2f0a27a9f09428b1847b4580640b9d1e58
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <94965be37add0983672e48ecb33cdbda92b62579
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <9cac69912052a4def571fedf1cb9bb4ec590e25a
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <cb5466783793e66272624cf71925ae1d1ba32083
- Affected versionversion=9ae326a69004dea8af2dae4fde58de27db700a8d <e21a2f17566cbd64926fb8f16323972f7a064444
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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