From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89936: iio: dac: m62332: Fix regulator reference count imbalance
Date: Wed, 16 Sep 2026 11:31:06 +0100 [thread overview]
Message-ID: <2026091646-CVE-2026-89936-85a2@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
iio: dac: m62332: Fix regulator reference count imbalance
m62332_set_value() enables the Vcc regulator on every write of a
non-zero value and disables it on every write of zero, without tracking
the channel's current state. Because the regulator is reference counted,
changing a channel directly from one non-zero value to another enables
it more than once, while a later write of zero disables it only once.
The reference count never returns to zero and the regulator is left
enabled indefinitely.
Only enable the regulator on the transition from zero to non-zero, and
only disable it on the transition from non-zero to zero, using the
previously stored channel value to detect the edge. Balance the
regulator on the I2C error path so the reference count stays consistent
if the write fails.
The Linux kernel CVE team has assigned CVE-2026-89936 to this issue.
Affected and fixed versions
===========================
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 5.10.270 with commit bac0ed8bee651aa841375edf72c6ab1d10ac80c6
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 5.15.221 with commit 9263b9ad968a563337a60e0eb66e35186e1faf9a
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 6.1.188 with commit 1d3a7d7dd3adee19e00be2b2237140f0fe169484
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 6.6.157 with commit f5acb824277a97a5210c454872202bf7f08c75d4
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 6.12.110 with commit ae18d2d2ef27a4d04fda6e30c23774513dc9be1e
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 6.18.51 with commit 08ac8d2976d57aa943d64e351c4d0bd8bb0c6de9
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 7.2.5 with commit 9fe22f563b2a0fdb11fd3711a8c39c023629c08a
Issue introduced in 4.2 with commit b87b0c0f81e8d11c881b726b886b7502ab67d884 and fixed in 7.3-rc1 with commit a130404ce0b69ca1438126bd81c1985d3b4d2e6f
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-2026-89936
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/dac/m62332.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/bac0ed8bee651aa841375edf72c6ab1d10ac80c6
https://git.kernel.org/stable/c/9263b9ad968a563337a60e0eb66e35186e1faf9a
https://git.kernel.org/stable/c/1d3a7d7dd3adee19e00be2b2237140f0fe169484
https://git.kernel.org/stable/c/f5acb824277a97a5210c454872202bf7f08c75d4
https://git.kernel.org/stable/c/ae18d2d2ef27a4d04fda6e30c23774513dc9be1e
https://git.kernel.org/stable/c/08ac8d2976d57aa943d64e351c4d0bd8bb0c6de9
https://git.kernel.org/stable/c/9fe22f563b2a0fdb11fd3711a8c39c023629c08a
https://git.kernel.org/stable/c/a130404ce0b69ca1438126bd81c1985d3b4d2e6f
reply other threads:[~2026-09-16 10:39 UTC|newest]
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