CVE-2026-74375: md/raid1,raid10: fix deadlock in read error recovery path

From: Greg Kroah-Hartman <[email protected]>

Description
===========

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

md/raid1,raid10: fix deadlock in read error recovery path

raid1d and raid10d may resubmit a split md cloned bio while handling
a read error. In this case, resubmitting the bio can lead to a deadlock
if the array is suspended before md_handle_request() acquires an
active_io reference via percpu_ref_tryget_live().

Since the cloned bio already holds an active_io reference,
trying to acquire another reference via percpu_ref_tryget_live()
can lead to a deadlock while the array is suspended.

Fix this by using percpu_ref_get() for md cloned bios.

The Linux kernel CVE team has assigned CVE-2026-74375 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.6 with commit bb2a9acefaf9ce5bbc1e70f407e34599233d0243 and fixed in 7.1.5 with commit 38777f014c37972868f1733a651c85288bb8a757
	Issue introduced in 6.6 with commit bb2a9acefaf9ce5bbc1e70f407e34599233d0243 and fixed in 7.2-rc1 with commit 7b15c24f805339a585cfe7d72f446b7e88b9bcc0

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-74375
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/md/md.c
	drivers/md/md.h


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/38777f014c37972868f1733a651c85288bb8a757
	https://git.kernel.org/stable/c/7b15c24f805339a585cfe7d72f446b7e88b9bcc0