media: rtl2832_sdr: use vb2_video_unregister_device() on remove to fix DMA leak

{
  "id": "9ae2dfc8f86c6b07dec16dfc85a3e4208903f68045a567f1c5342c541a89678d",
  "url": "https://osv.dev/vulnerability/CVE-2026-89881",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "media: rtl2832_sdr: use vb2_video_unregister_device() on remove to fix DMA leak",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: media: rtl2832_sdr: use vb2_video_unregister_device() on remove to fix DMA leak rtl2832_sdr_remove() runs on USB disconnect and clears dev->udev to NULL before any pending streaming teardown has run. When user space later closes its file descriptor, vb2 calls rtl2832_sdr_stop_streaming() which in turn calls rtl2832_sdr_free_stream_bufs(). That helper releases each coherent buffer with: usb_free_coherent(dev->udev, dev->buf_size, dev->buf_list[dev->buf_num], dev->dma_addr[dev->buf_num]); usb_free_coherent() returns immediately when its dev argument is NULL, so every DMA stream buffer that was live at disconnect is silently leaked. The URBs allocated in rtl2832_sdr_alloc_urbs() outlive the device for the same reason. The rtl2832_sdr driver uses vb2_fop_release() in its file_operations, so replace video_unregister_device(&dev->vdev) with vb2_video_unregister_device(&dev->vdev) and move it before clearing dev->udev. vb2_video_unregister_device() releases the vb2 queue, which synchronously runs rtl2832_sdr_stop_streaming() if streaming is active, so URBs and coherent DMA stream buffers are freed while dev->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(&dev->vb_queue_lock) / mutex_lock(&dev->v4l2_lock) pair around the unregister sequence would self-deadlock and has been removed. A short v4",
    "evidence": "osv:CVE-2026-89881",
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    "severity": "unknown",
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      "aliases": [
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      "modified": "2026-10-28T02:30:43.603126321Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/034b6a4f9589c04bc3f2bd5125658cd72d3e17c8",
        "https://git.kernel.org/stable/c/053581d4657c6b5289c5de71a4828d313c005189",
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        "https://git.kernel.org/stable/c/234c46b95a032232e31fa5987b84fb8f87a9693b",
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        "https://git.kernel.org/stable/c/dabb047c62668f280998e29117c55e41aabac336",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89881.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89881",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89881.json"
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    "related_cves": [
      {
        "value": "CVE-2026-89881",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 511561,
  "published_at": "2026-09-16T10:31:46.966+00:00"
}