CVE-2026-53123
Low risk· EPSS 7%Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
A bug was found in the Linux kernel md module (RAID456) that can cause a deadlock during RAID reshape. When I/O waits for reshape progress and the user freezes the reshape and writes to md/suspend_lo or md/suspend_hi sysfs files, mddev_suspend() waits for all I/O to drain, which never completes because reshape is frozen.
Risk Assessment
The deadlock can prevent normal system operation by blocking I/O on the RAID array and preventing device suspension. This may lead to data unavailability and require manual administrator intervention.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit adding wake_up(&conf->wait_for_reshape) call in raid5_prepare_suspend()). Before the update, avoid simultaneously performing RAID reshape operations and writing to md/suspend_lo or md/suspend_hi files.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: md: wake raid456 reshape waiters before suspend During raid456 reshape, direct IO across the reshape position can sleep in raid5_make_request() waiting for reshape progress while still holding an active_io reference. If userspace then freezes reshape and writes md/suspend_lo or md/suspend_hi, mddev_suspend() kills active_io and waits for all in-flight IO to drain. This can deadlock: the IO needs reshape progress to continue, but the reshape thread is already frozen, so the active_io reference is never dropped and suspend never completes. raid5_prepare_suspend() already wakes wait_for_reshape for dm-raid. Do the same for normal md suspend when reshape is already interrupted, so waiting raid456 IO can abort, drop its reference, and let suspend finish. The mdadm test tests/25raid456-reshape-deadlock reproduces the hang.