{"id":"CVE-2026-89881","title":"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 pen…","summary":"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 pen…","severity":"medium","vendor":"Linux","product":"Linux","affected":["Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < 234c46b95a032232e31fa5987b84fb8f87a9693b","Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < 034b6a4f9589c04bc3f2bd5125658cd72d3e17c8","Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < 0ef9f19010ae4ba93aca211ea8f0081b9bf7aab2","Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < 053581d4657c6b5289c5de71a4828d313c005189","Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < bbf15e83c37d9ac938b7c35c02b748fe54230010","Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < 7443b16b6dd8889a3b9c5236a09e7c58f0d11dae","Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < a0d9d9a3b41a1346c26af57aade6ba3f552fa171","Linux >= 771138920eafa399f68d3492c8a75dfeea23474b < dabb047c62668f280998e29117c55e41aabac336","Linux 3.15"],"published":"2026-09-16","updated":"2026-09-16","sourceUpdated":"2026-09-16T11:16:56.503","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89881","references":[{"url":"https://git.kernel.org/stable/c/034b6a4f9589c04bc3f2bd5125658cd72d3e17c8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/053581d4657c6b5289c5de71a4828d313c005189","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/0ef9f19010ae4ba93aca211ea8f0081b9bf7aab2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/234c46b95a032232e31fa5987b84fb8f87a9693b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7443b16b6dd8889a3b9c5236a09e7c58f0d11dae","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a0d9d9a3b41a1346c26af57aade6ba3f552fa171","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bbf15e83c37d9ac938b7c35c02b748fe54230010","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dabb047c62668f280998e29117c55e41aabac336","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89881.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89881"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2535224"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89881"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89881"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89881.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-09-16T10:53:53.984Z","epss":0.00216,"epssPercentile":0.11994,"cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-772"],"slug":"CVE-2026-89881","body":"## Overview\n\nIn 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/\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-10-05 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89881.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":216257,"id":"CVE-2026-89881","ts":1791274050121,"field":"cvss","old":null,"new":"5.5"},{"seq":216256,"id":"CVE-2026-89881","ts":1791274050121,"field":"severity","old":"none","new":"medium"}]}