From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-43309: md raid: fix hang when stopping arrays with metadata through dm-raid
Date: Fri, 8 May 2026 15:12:14 +0200 [thread overview]
Message-ID: <2026050859-CVE-2026-43309-873c@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
md raid: fix hang when stopping arrays with metadata through dm-raid
When using device-mapper's dm-raid target, stopping a RAID array can cause
the system to hang under specific conditions.
This occurs when:
- A dm-raid managed device tree is suspended from top to bottom
(the top-level RAID device is suspended first, followed by its
underlying metadata and data devices)
- The top-level RAID device is then removed
Removing the top-level device triggers a hang in the following sequence:
the dm-raid destructor calls md_stop(), which tries to flush the
write-intent bitmap by writing to the metadata sub-devices. However, these
devices are already suspended, making them unable to complete the write-intent
operations and causing an indefinite block.
Fix:
- Prevent bitmap flushing when md_stop() is called from dm-raid
destructor context
and avoid a quiescing/unquescing cycle which could also cause I/O
- Still allow write-intent bitmap flushing when called from dm-raid
suspend context
This ensures that RAID array teardown can complete successfully even when the
underlying devices are in a suspended state.
This second patch uses md_is_rdwr() to distinguish between suspend and
destructor paths as elaborated on above.
The Linux kernel CVE team has assigned CVE-2026-43309 to this issue.
Affected and fixed versions
===========================
Fixed in 6.18.16 with commit 24783dd06de870d646c25207bae186f78195f912
Fixed in 6.19.6 with commit 338378dfffbdbb8d37a18f0a0c0358812671f91e
Fixed in 7.0 with commit cefcb9297fbdb6d94b61787b4f8d84f55b741470
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-2026-43309
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
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/24783dd06de870d646c25207bae186f78195f912
https://git.kernel.org/stable/c/338378dfffbdbb8d37a18f0a0c0358812671f91e
https://git.kernel.org/stable/c/cefcb9297fbdb6d94b61787b4f8d84f55b741470
reply other threads:[~2026-05-08 13:14 UTC|newest]
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