CVE-2025-21685

/// Technical description

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

platform/x86: lenovo-yoga-tab2-pro-1380-fastcharger: fix serdev race

The yt2_1380_fc_serdev_probe() function calls devm_serdev_device_open()

before setting the client ops via serdev_device_set_client_ops(). This

ordering can trigger a NULL pointer dereference in the serdev controller's

receive_buf handler, as it assumes serdev->ops is valid when

SERPORT_ACTIVE is set.

This is similar to the issue fixed in commit 5e700b384ec1

("platform/chrome: cros_ec_uart: properly fix race condition") where

devm_serdev_device_open() was called before fully initializing the

device.

Fix the race by ensuring client ops are set before enabling the port via

devm_serdev_device_open().

Note, serdev_device_set_baudrate() and serdev_device_set_flow_control()

calls should be after the devm_serdev_device_open() call.

/// 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