CVE-2026-53123: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 6.7, before 6.12.91 (fixed in 6.12.91); from 6.13, before 6.18.33 (fixed in 6.18.33); from 6.19, before 7.0.10 (fixed in 7.0.10)

Published 2026-06-24. Last modified 2026-07-23.