md: wake raid456 reshape waiters before suspend

Summary

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.

Timeline

1. Jun 24, 2026, 4:30 PM UTCCVE published
2. Oct 21, 2026, 12:42 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 714d20150ed85811193ae07a494d91f9927c590f · fixed in 8b6a72420821e6da2cab6a69d5233500d2698b93; From 714d20150ed85811193ae07a494d91f9927c590f · fixed in ff6b93410192b812d73cc54062529715b2dc849f; From 714d20150ed85811193ae07a494d91f9927c590f · fixed in 8ae3e14d7f3df58f7f49c02d74344e3dcd5f84f0; From 714d20150ed85811193ae07a494d91f9927c590f · fixed in cf86bb53b9c92354904a328e947a05ffbfdd1840; From 6.6.160 · fixed in 6.7

• Linux Linux

  6.7

• KernelLinux

  From 6.7.0 · fixed in 6.12.91; From 6.13.0 · fixed in 6.18.33; From 6.19.0 · fixed in 7.0.10

References 4