CVE-2026-89942

/// Technical description

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

iio: buffer: Fix potential use-after-free in anonymous buffer release

An anonymous buffer handle holds a reference to the underlying IIO device.

The reference is dropped in the buffer handle's release function. If the

device has been removed, either through unbind or hot-unplug, the buffer

handle might hold the last reference.

The release function takes the mutex for the buffer using a guard, which

means the unlock happens after all the code in the function, including

`iio_device_put()`. If the anonymous buffer holds the last reference this

might free both the IIO device and the buffer, which contains the mutex,

leading to use-after-free when the mutex is unlocked.

Fix this by using a scoped guard just around the buffer dmabuf list access,

making sure the mutex is unlocked before releasing the IIO device.

Version 10 of the patch that introduced this issue used this exact scheme

of first unlocking and then dropping

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References