CVE-2026-90278

In the Linux kernel, the following vulnerability has been resolved:

md: wait for behind writes before destroying bitmap

__md_stop() destroyed the bitmap before calling mddev_detach(). That made

mddev_detach() skip bitmap_ops->wait_behind_writes(), because the bitmap

was already disconnected from mddev.

This was still safe for the legacy bitmap because bitmap_destroy() waits

for behind writes itself. llbitmap keeps that wait in its

->wait_behind_writes() operation instead, while ->destroy() tears down the

llbitmap storage. With the old ordering, RAID1 behind-write completions

could still run after llbitmap storage had been freed.

Call mddev_detach() before md_bitmap_destroy() so the common detach path

can wait for behind writes while the bitmap is still alive. Only destroy

the bitmap after those users are gone.