{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.85-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.19.14-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  media: mediatek: vcodec: fix use-after-free in encoder release path  The fops_vcodec_release() function frees the context structure (ctx) without first cancelling any pending or running work in ctx-\u003eencode_work. This creates a race window where the workqueue handler (mtk_venc_worker) may still be accessing the context memory after it has been freed.  Race condition:      CPU 0 (release path)               CPU 1 (workqueue)     ---------------------               ------------------     fops_vcodec_release()       v4l2_m2m_ctx_release()         v4l2_m2m_cancel_job()         // waits for m2m job \"done\"                                         mtk_venc_worker()                                           v4l2_m2m_job_finish()                                           // m2m job \"done\"                                           // BUT worker still running!                                           // post-job_finish access:                                         other ctx dereferences                                           // UAF if ctx already freed         // returns (job \"done\")       kfree(ctx)  // ctx freed  Root cause: The v4l2_m2m_ctx_release() only waits for the m2m job lifecycle (via TRANS_RUNNING flag), not the workqueue lifecycle. After v4l2_m2m_job_finish() is called, the m2m framework considers the job complete and v4l2_m2m_ctx_release() returns, but the worker function continues executing and may still access ctx.  The work is queued during encode operations via:   queue_work(ctx-\u003edev-\u003eencode_workqueue, \u0026ctx-\u003eencode_work) The worker function accesses ctx-\u003em2m_ctx, ctx-\u003edev, and other ctx fields even after calling v4l2_m2m_job_finish().  This vulnerability was confirmed with KASAN by running an instrumented test module that widens the post-job_finish race window. KASAN detected:    BUG: KASAN: slab-use-after-free in mtk_venc_worker+0x159/0x180   Read of size 4 at addr ffff88800326e000 by task kworker/u8:0/12    Workqueue: mtk_vcodec_enc_wq mtk_venc_worker    Allocated by task 47:     __kasan_kmalloc+0x7f/0x90     fops_vcodec_open+0x85/0x1a0    Freed by task 47:     __kasan_slab_free+0x43/0x70     kfree+0xee/0x3a0     fops_vcodec_release+0xb7/0x190  Fix this by calling cancel_work_sync(\u0026ctx-\u003eencode_work) before kfree(ctx). This ensures the workqueue handler is both cancelled (if pending) and synchronized (waits for any running handler to complete) before the context is freed.  Placement rationale: The fix is placed after v4l2_ctrl_handler_free() and before list_del_init(\u0026ctx-\u003elist). At this point, all m2m operations are done (v4l2_m2m_ctx_release() has returned), and we need to ensure the workqueue is synchronized before removing ctx from the list and freeing it.  Note: The open error path does NOT need cancel_work_sync() because INIT_WORK() only initializes the work structure - it does not schedule it. Work is only scheduled later during device_run() operations.",
  "id": "DEBIAN-CVE-2026-31584",
  "modified": "2026-09-14T16:47:29.774756904Z",
  "published": "2026-04-24T15:16:33.117Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-31584"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-31584"
  ]
}