CyberRota Analysis
AI-GeneratedThe vulnerability in the Linux kernel affects the Bluetooth 6LoWPAN implementation, where a race condition allows a scheduled work item to execute against stale state after the debugfs operation has completed. This can lead to a use-after-free condition, potentially resulting in system instability or exploitation. Organizations utilizing Linux systems with Bluetooth capabilities, especially those implementing 6LoWPAN, should prioritize applying patches to mitigate this risk.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: 6lowpan: avoid untracked enable work lowpan_enable_set() allocates a temporary work item and schedules do_enable_set() on system_wq, then returns to debugfs. The debugfs active operation has ended at that point, but the worker still executes module text and manipulates enable_6lowpan and listen_chan. bt_6lowpan_exit() removes the debugfs files and immediately closes and puts listen_chan. It has no pointer to the queued work item, so it cannot cancel or flush it before tearing down the state that the worker uses. The buggy scenario involves two paths, with each column showing the order within that path: debugfs enable write module exit 1. lowpan_enable_set() allocates 1. bt_6lowpan_exit() removes set_enable work the debugfs file 2. schedule_work() queues 2. bt_6lowpan_exit() closes do_enable_set() and puts listen_chan 3. the write operation returns 3. module teardown can continue 4. do_enable_set() later runs against stale state Run the enable state transition synchronously in lowpan_enable_set() instead. The simple debugfs setter can sleep, and this file already handles the 6LoWPAN control write synchronously under the same set_lock. Once the setter returns, debugfs removal covers the whole operation and exit can no longer race with an untracked work item. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in do_enable_set+0x113/0x2e0 Workqueue: events do_enable_set [bluetooth_6lowpan] The buggy address belongs to the object at ffff888109cb8000