CVE Catalog

CVE-2025-40249

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel, the gpio/cdev driver has a use-after-free risk. A GPIO event may be emitted after the file descriptor's reference count reached zero but before .release() is called.

Risk Assessment

The organization risks system crashes or potential privilege escalation via GPIO event manipulation.

Recommendation

Update the Linux kernel to a version containing the fix for CVE-2025-40249.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: gpio: cdev: make sure the cdev fd is still active before emitting events With the final call to fput() on a file descriptor, the release action may be deferred and scheduled on a work queue. The reference count of that descriptor is still zero and it must not be used. It's possible that a GPIO change, we want to notify the user-space about, happens AFTER the reference count on the file descriptor associated with the character device went down to zero but BEFORE the .release() callback was called from the workqueue and so BEFORE we unregistered from the notifier. Using the regular get_file() routine in this situation triggers the following warning: struct file::f_count incremented from zero; use-after-free condition present! So use the get_file_active() variant that will return NULL on file descriptors that have been or are being released.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS