CVE-2026-45955
Analyzed Analyzed - Analysis Complete
Linux kernel md-llbitmap percpu_ref Resurrection Failure

Publication date: 2026-05-27

Last updated on: 2026-06-16

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: md/md-llbitmap: fix percpu_ref not resurrected on suspend timeout When llbitmap_suspend_timeout() times out waiting for percpu_ref to become zero, it returns -ETIMEDOUT without resurrecting the percpu_ref. The caller (md_llbitmap_daemon_fn) then continues to the next page without calling llbitmap_resume(), leaving the percpu_ref in a killed state permanently. Fix this by resurrecting the percpu_ref before returning the error, ensuring the page control structure remains usable for subsequent operations.
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Meta Information
Published
2026-05-27
Last Modified
2026-06-16
Generated
2026-06-16
AI Q&A
2026-05-27
EPSS Evaluated
2026-06-15
NVD
CVE-2026-45955
EUVD
EUVD-2026-32239
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 6.19 (inc) to 6.19.4 (exc)
linux linux_kernel From 6.18 (inc) to 6.18.14 (exc)
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Exploitability
CWE
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability exists in the Linux kernel's md/md-llbitmap component. When the function llbitmap_suspend_timeout() times out while waiting for a reference counter (percpu_ref) to reach zero, it returns an error (-ETIMEDOUT) but fails to restore (resurrect) the percpu_ref. As a result, the calling function (md_llbitmap_daemon_fn) proceeds without calling llbitmap_resume(), leaving the percpu_ref permanently in a killed state. This means the page control structure associated with it becomes unusable for future operations.

Impact Analysis

The impact of this vulnerability is that certain page control structures in the Linux kernel may become permanently unusable due to the percpu_ref being left in a killed state. This can lead to potential system instability or malfunction in the handling of these structures, possibly affecting the reliability of the system's storage or memory management components that rely on md/md-llbitmap.

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