CVE-2026-89936 iio: dac: m62332: Fix regulator reference count imbalance
A reference count imbalance in the m62332 DAC driver allows local attackers to keep regulators enabled indefinitely, potentially causing resource exhaustion.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89936?
CVE-2026-89936 is a denial of service vulnerability in Linux, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-89936?
How do I fix CVE-2026-89936?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-89936 being exploited?
There is no known exploitation of CVE-2026-89936 in the wild and no public exploit code.
Sources
Also known as AZL-101481, BELL-CVE-2026-89936, DEBIAN-CVE-2026-89936, GHSA-93hj-782q-v32m, UBUNTU-CVE-2026-89936.