CVE-2026-45955: md/md-llbitmap: fix percpu_ref not resurrected on suspend timeout

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-10-19
Weakness: CWE-404

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.

Affected products

Linux kernel: from 6.18 before 6.18.14; from 6.19 before 6.19.4 — fixed in 6.18.14, 6.19.4

How to fix

Upgrade to a fixed version: Linux kernel 6.18.14, 6.19.4. Check the vendor advisory for mitigations.

References

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