CVE-2026-98669: iio: buffer: serialize buffer teardown with mode claims

CVE-2026-98669: iio: buffer: serialize buffer teardown with mode claims

[Greg Kroah-Hartman]

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

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

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

iio: buffer: serialize buffer teardown with mode claims

Buffer-mode claims hold mlock to guarantee that the device remains in
buffer mode until the claim is released. Normal buffer updates take
info_exist_lock followed by mlock in iio_update_buffers().

However, iio_device_unregister() disables and deactivates all buffers
without taking mlock. This can invalidate buffer state, including
active_scan_mask, while a buffer-mode claim is held.

Take mlock in iio_disable_all_buffers() so that unregister honors the
mode-claim lifetime guarantee. The info_exist_lock -> mlock ordering
matches iio_update_buffers().

The Linux kernel CVE team has assigned CVE-2026-98669 to this issue.


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

	Issue introduced in 6.2 with commit 0a8565425afd8ba0e1a0ea73e21da119ee6dacea and fixed in 6.12.113 with commit 89f3852a28fcf7bab599280cb082baa0675536db
	Issue introduced in 6.2 with commit 0a8565425afd8ba0e1a0ea73e21da119ee6dacea and fixed in 6.18.56 with commit b466db9e68b4741af85f6c017e2bb0a2f025053f
	Issue introduced in 6.2 with commit 0a8565425afd8ba0e1a0ea73e21da119ee6dacea and fixed in 7.2.10 with commit e63188d77e10c0951bf67da6c295f768fd1abf4b
	Issue introduced in 6.2 with commit 0a8565425afd8ba0e1a0ea73e21da119ee6dacea and fixed in 7.3-rc6 with commit 84bb0fc46ccf6a545b8fdf57cda83770186ed8dd
	Issue introduced in 5.15.137 with commit a9c471892d75847671a246619c2148578f22bbc6
	Issue introduced in 6.1.60 with commit 7bca0af538a49dacb1470f233be0676bdc09605b

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-2026-98669
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/iio/industrialio-buffer.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/89f3852a28fcf7bab599280cb082baa0675536db
	https://git.kernel.org/stable/c/b466db9e68b4741af85f6c017e2bb0a2f025053f
	https://git.kernel.org/stable/c/e63188d77e10c0951bf67da6c295f768fd1abf4b
	https://git.kernel.org/stable/c/84bb0fc46ccf6a545b8fdf57cda83770186ed8dd