CVE-2025-71079

/// Technical description

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

net: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write

A deadlock can occur between nfc_unregister_device() and rfkill_fop_write()

due to lock ordering inversion between device_lock and rfkill_global_mutex.

The problematic lock order is:

Thread A (rfkill_fop_write):

rfkill_fop_write()

mutex_lock(&rfkill_global_mutex)

rfkill_set_block()

nfc_rfkill_set_block()

nfc_dev_down()

device_lock(&dev->dev) <- waits for device_lock

Thread B (nfc_unregister_device):

nfc_unregister_device()

device_lock(&dev->dev)

rfkill_unregister()

mutex_lock(&rfkill_global_mutex) <- waits for rfkill_global_mutex

This creates a classic ABBA deadlock scenario.

Fix this by moving rfkill_unregister() and rfkill_destroy() outside the

device_lock critical section. Store the rfkill pointer in a local variable

before releasing the lock, then call rfkill_unregister(

/// 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