CVE-2026-90390: md/bitmap: resume array on backlog_store() error path
In the Linux kernel, the following vulnerability has been resolved:
md/bitmap: resume array on backlogstore() error path
backlogstore() suspends the array before checking whether a write-mostly device exists. If no such device exists, the error path only unlocks reconfigmutex and leaves the array suspended, blocking subsequent I/O.
Use mddevunlockandresume() to release both states.
Affected Software
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems using Linux md arrays are exposed when backlog_store() is invoked on an array that has no write-mostly device. The described failure leaves that array suspended and blocks subsequent I/O.
What action triggers the affected error path?
The trigger is an attempt to use backlog_store() when no write-mostly device exists in the array. The array is suspended before that condition is checked, and the pre-fix error path does not resume it.
How can administrators tell whether an array has been affected?
An affected array will remain suspended after the backlog_store() operation fails because no write-mostly device exists. Subsequent I/O to that array is blocked.