Linux Kernel up to 6.16.3/6.17-rc2 kernel/notifier.c devm_register_sys_off_handler denial of service

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.16.3/6.17-rc2. It has been classified as critical. Affected is the function devm_register_sys_off_handler of the file kernel/notifier.c. Performing a manipulation results in denial of service. This vulnerability is known as CVE-2025-39771. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.16.3/6.17-rc2. This affects the function devm_register_sys_off_handler of the file kernel/notifier.c. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: regulator: pca9450: Use devm_register_sys_off_handler With module test, there is error dump: ------------[ cut here ]------------ notifier callback pca9450_i2c_restart_handler already registered WARNING: kernel/notifier.c:23 at notifier_chain_register+0x5c/0x88, CPU#0: kworker/u16:3/50 Call trace: notifier_chain_register+0x5c/0x88 (P) atomic_notifier_chain_register+0x30/0x58 register_restart_handler+0x1c/0x28 pca9450_i2c_probe+0x418/0x538 i2c_device_probe+0x220/0x3d0 really_probe+0x114/0x410 __driver_probe_device+0xa0/0x150 driver_probe_device+0x40/0x114 __device_attach_driver+0xd4/0x12c So use devm_register_sys_off_handler to let kernel handle the resource free to avoid kernel dump.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-39771 since 04/16/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 264765 (Linux Distros Unpatched Vulnerability : CVE-2025-39771), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.16.4 or 6.17-rc3 eliminates this vulnerability. Applying a patch 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 (264765) and CERT Bund (WID-SEC-2025-2040). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Google Cloud Platform
• Amazon Linux 2
• Red Hat Enterprise Linux
• Fedora Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel
• Proxmox Virtual Environment
• Proxmox Backup Server
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.16.0
• 6.16.1
• 6.16.2
• 6.16.3
• 6.17-rc1
• 6.17-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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