CVE-2025-71079
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() after releasing device_lock. This change is safe because rfkill_fop_write() holds rfkill_global_mutex while calling the rfkill callbacks, and rfkill_unregister() also acquires rfkill_global_mutex before cleanup. Therefore, rfkill_unregister() will wait for any ongoing callback to complete before proceeding, and device_del() is only called after rfkill_unregister() returns, preventing any use-after-free. The similar lock ordering in nfc_register_device() (device_lock -> rfkill_global_mutex via rfkill_register) is safe because during registration the device is not yet in rfkill_list, so no concurrent rfkill operations can occur on this device.
How to fix
- linux linux_kernel4.5, 4.10, 4.15, 4.20, 5.5, 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64, 6.18.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 4.4.293 ≤ v < 4.5, 4.9.291 ≤ v < 4.10, 4.14.256 ≤ v < 4.15, 4.19.218 ≤ v < 4.20, 5.4.162 ≤ v < 5.5, 5.10.82 ≤ v < 5.10.248, 5.15.5 ≤ v < 5.15.198, 5.16.1 ≤ v < 6.1.160, 6.2 ≤ v < 6.6.120, 6.7 ≤ v < 6.12.64, 6.13 ≤ v < 6.18.4, 5.16, 6.19 | 4.5, 4.10, 4.15, 4.20, 5.5, 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64, 6.18.4 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.