CVE-2026-89901

Summary

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/

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/c9081e2655188d2d134a741aec837dc70439d505
• https://git.kernel.org/stable/c/75089cea32e5055773bd13116236d08fdc98678a
• https://git.kernel.org/stable/c/155d0378ae0d6305cc4840583a6b42d2d0595bff
• https://git.kernel.org/stable/c/6e4ea90fdc6608cd5fac342e146ab6ae15d430bc
• https://git.kernel.org/stable/c/a9a8c37ddda9fa3687b142be9098e1c37b8faf35
• https://git.kernel.org/stable/c/297fee023f46d771a844520675692ea089d80d9d
• https://git.kernel.org/stable/c/c6749ac8f59cc80eb1b2d52f167fdf13e12655cc
• https://git.kernel.org/stable/c/2f378dc45e685fc825d2dd08e7864666d6fcc009

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