CVE-2026-46051: md/raid5: fix soft lockup in retry_aligned_read()

CVE-2026-46051: md/raid5: fix soft lockup in retry_aligned_read()

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

md/raid5: fix soft lockup in retry_aligned_read()

When retry_aligned_read() encounters an overlapped stripe, it releases
the stripe via raid5_release_stripe() which puts it on the lockless
released_stripes llist. In the next raid5d loop iteration,
release_stripe_list() drains the stripe onto handle_list (since
STRIPE_HANDLE is set by the original IO), but retry_aligned_read()
runs before handle_active_stripes() and removes the stripe from
handle_list via find_get_stripe() -> list_del_init(). This prevents
handle_stripe() from ever processing the stripe to resolve the
overlap, causing an infinite loop and soft lockup.

Fix this by using __release_stripe() with temp_inactive_list instead
of raid5_release_stripe() in the failure path, so the stripe does not
go through the released_stripes llist. This allows raid5d to break out
of its loop, and the overlap will be resolved when the stripe is
eventually processed by handle_stripe().

The Linux kernel CVE team has assigned CVE-2026-46051 to this issue.


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

	Issue introduced in 3.12 with commit 773ca82fa1ee58dd1bf88b6a5ca385ec83a2cac6 and fixed in 6.6.140 with commit 09880592f5a9dc73377d6eb5ac123537b5f8df49
	Issue introduced in 3.12 with commit 773ca82fa1ee58dd1bf88b6a5ca385ec83a2cac6 and fixed in 6.12.86 with commit 80fc6ca2cbde018d52e13f305edcd643911bd94b
	Issue introduced in 3.12 with commit 773ca82fa1ee58dd1bf88b6a5ca385ec83a2cac6 and fixed in 6.18.27 with commit 1985cb3247e87ff6b8ca4bc5f9626f4f51024507
	Issue introduced in 3.12 with commit 773ca82fa1ee58dd1bf88b6a5ca385ec83a2cac6 and fixed in 7.0.4 with commit 883cc33b7af1c448663287f069ef9dfea001e90f
	Issue introduced in 3.12 with commit 773ca82fa1ee58dd1bf88b6a5ca385ec83a2cac6 and fixed in 7.1-rc1 with commit 7f9f7c697474268d9ef9479df3ddfe7cdcfbbffc

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-2026-46051
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/raid5.c


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/09880592f5a9dc73377d6eb5ac123537b5f8df49
	https://git.kernel.org/stable/c/80fc6ca2cbde018d52e13f305edcd643911bd94b
	https://git.kernel.org/stable/c/1985cb3247e87ff6b8ca4bc5f9626f4f51024507
	https://git.kernel.org/stable/c/883cc33b7af1c448663287f069ef9dfea001e90f
	https://git.kernel.org/stable/c/7f9f7c697474268d9ef9479df3ddfe7cdcfbbffc