CVE-2025-39771 regulator: pca9450: Use devm_register_sys_off_handler
A kernel warning and potential crash occur in the PCA9450 regulator driver due to duplicate notifier registration, requiring a patch to use managed resource handling.
- 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-2025-39771?
CVE-2025-39771 is a medium-severity denial of service vulnerability in Linux kernel, published on 11 Sep 2025. 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:
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.
Which versions are affected by CVE-2025-39771?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-39771?
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-2025-39771 being exploited?
There is no known exploitation of CVE-2025-39771 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-39771, DEBIAN-CVE-2025-39771, GHSA-fwgp-x7rw-mmhf, ROOT-OS-UBUNTU-2204-CVE-2025-39771, ROOT-OS-UBUNTU-2404-CVE-2025-39771, UBUNTU-CVE-2025-39771.