Linux Kernel up to 6.12.10 yt2_1380_fc_serdev_probe null pointer dereference

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.12.10. The impacted element is the function yt2_1380_fc_serdev_probe. The manipulation leads to null pointer dereference. This vulnerability is traded as CVE-2025-21685. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.12.10. This issue affects the function yt2_1380_fc_serdev_probe. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-21685 since 12/29/2024. The exploitation is known to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 234757 (Ubuntu 24.04 LTS / 24.10 : Linux kernel vulnerabilities (USN-7445-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.11 eliminates this vulnerability. Applying the patch 3f67e07873df3c6d9ce2582260b83732e1d3a40b/59616a91e5e74833b2008b56c66879857c616006 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (234757) and CERT Bund (WID-SEC-2025-0297). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Open Source Linux Kernel
• Debian Linux
• Ubuntu Linux
• SUSE Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10

License

• open-source

Website

• Vendor: https://www.kernel.org/

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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