CVE-2026-89901

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

media: airspy: use vb2_video_unregister_device() on disconnect to fix NULL deref

airspy_disconnect() clears s->udev under v4l2_lock, but

airspy_stop_streaming() unconditionally calls airspy_ctrl_msg() and

airspy_free_stream_bufs() afterwards. If a streaming user closes the

device after disconnect, stop_streaming() runs and dereferences the

NULL s->udev:

airspy_stop_streaming()

airspy_ctrl_msg(s, CMD_RECEIVER_MODE, 0, 0, NULL, 0)

usb_sndctrlpipe(s->udev, 0) /* NULL deref */

airspy_free_stream_bufs(s)

usb_free_coherent(s->udev, ...) /* NULL deref */

The airspy driver uses vb2_fop_release() in its file_operations, so

replace video_unregister_device(&s->vdev) with

vb2_video_unregister_device(&s->vdev) and move it before clearing

s->udev. vb2_video_unregister_device() releases the vb2 queue, which

synchronously runs airspy_stop_streaming() if streaming is active, so

the URBs, coherent DMA stream buffers and the hardware stop control

message all execute while s->udev is still valid.

vb2_video_unregister_device() locks vdev->queue->lock (vb_queue_lock)

internally, and stop_streaming() locks v4l2_lock, so the previous outer

mutex_lock(&s->vb_queue_lock) / mutex_lock(&s->v4l2_lock) pair around

the unregister sequence would self-deadlock and has been removed. A

short v4l2_lock critical section around s->udev = NULL remains so any

ioctl path that still holds the file descriptor sees coherent state.

Issue identified by automated review of the INV-003 series at

https://sashiko.dev/