{"cve":"CVE-2026-89881","nvd":{"published":"2026-09-16T11:16:56.503","modified":"2026-10-19T09:18:33.003","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: rtl2832_sdr: use vb2_video_unregister_device() on remove to fix DMA leak\n\nrtl2832_sdr_remove() runs on USB disconnect and clears dev->udev to\nNULL before any pending streaming teardown has run. When user space\nlater closes its file descriptor, vb2 calls rtl2832_sdr_stop_streaming()\nwhich in turn calls rtl2832_sdr_free_stream_bufs(). That helper releases\neach coherent buffer with:\n\n    usb_free_coherent(dev->udev, dev->buf_size,\n                      dev->buf_list[dev->buf_num],\n                      dev->dma_addr[dev->buf_num]);\n\nusb_free_coherent() returns immediately when its dev argument is NULL,\nso every DMA stream buffer that was live at disconnect is silently\nleaked. The URBs allocated in rtl2832_sdr_alloc_urbs() outlive the\ndevice for the same reason.\n\nThe rtl2832_sdr driver uses vb2_fop_release() in its file_operations,\nso replace video_unregister_device(&dev->vdev) with\nvb2_video_unregister_device(&dev->vdev) and move it before clearing\ndev->udev. vb2_video_unregister_device() releases the vb2 queue, which\nsynchronously runs rtl2832_sdr_stop_streaming() if streaming is active,\nso URBs and coherent DMA stream buffers are freed while dev->udev is\nstill valid.\n\nvb2_video_unregister_device() locks vdev->queue->lock (vb_queue_lock)\ninternally, and stop_streaming() locks v4l2_lock, so the previous outer\nmutex_lock(&dev->vb_queue_lock) / mutex_lock(&dev->v4l2_lock) pair\naround the unregister sequence would self-deadlock and has been removed.\nA short v4l2_lock critical section around dev->udev = NULL remains so\nany ioctl path that still holds the file descriptor sees coherent state.\n\nIssue identified by automated review of the INV-003 series at\nhttps://sashiko.dev/","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/034b6a4f9589c04bc3f2bd5125658cd72d3e17c8","https://git.kernel.org/stable/c/053581d4657c6b5289c5de71a4828d313c005189","https://git.kernel.org/stable/c/0ef9f19010ae4ba93aca211ea8f0081b9bf7aab2","https://git.kernel.org/stable/c/234c46b95a032232e31fa5987b84fb8f87a9693b","https://git.kernel.org/stable/c/7443b16b6dd8889a3b9c5236a09e7c58f0d11dae"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:54:41.405518556+00:00"},"epss":{"cve":"CVE-2026-89881","score":0.00216,"percentile":0.11957,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}