Bug 2535368 (CVE-2026-89936)

Summary: CVE-2026-89936 kernel: iio: dac: m62332: Fix regulator reference count imbalance
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's iio: dac: m62332 driver. The m62332_set_value() function incorrectly manages the reference count for the Vcc regulator. When a channel's value is changed directly from one non-zero value to another, the regulator is enabled multiple times, but only disabled once when the value returns to zero. This imbalance causes the regulator to remain enabled indefinitely, leading to a resource leak.
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Description OSIDB Bzimport 2026-09-16 12:22:39 UTC 
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.
Comment 1 Keith Grant 2026-09-22 12:56:40 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89936.mbox