{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "e2b2740f1242bc70b5b46da2cdbbaa419f490e59"
            },
            {
              "fixed": "67b589d09a96882d56842dced5698ed8dd06ce45"
            },
            {
              "fixed": "e239ea91b48180ed48a86ac25643832a02c88456"
            },
            {
              "fixed": "e24b33618231034bf01dfaff4fd3409d4b4d5b2e"
            },
            {
              "fixed": "d5e5cd3654d2b5359a12ea6586120f05b28634ee"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "fixed": "6.6.148"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.101"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.42"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68370.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: dummy_hcd: prevent fifo_req reuse during giveback\n\ndummy_hcd embeds a single shared usb_request (dum-\u003efifo_req) that the\n\"emulated single-request FIFO\" fast-path in dummy_queue() reuses for\nsmall IN transfers: it copies the caller's request into it\n(req-\u003ereq = *_req) and queues it, treating list_empty(\u0026fifo_req.queue)\nas \"the slot is free\".\n\nThe completion side (dummy_timer/transfer/nuke/dummy_dequeue) follows\nthe standard pattern: list_del_init(\u0026req-\u003equeue) unlinks the request,\nthen the lock is dropped and usb_gadget_giveback_request() invokes\nreq-\u003ecomplete().  But list_del_init() makes fifo_req.queue look empty\n*before* the completion callback returns, so a concurrent dummy_queue()\non another CPU sees the slot as free, reuses fifo_req and runs\nreq-\u003ereq = *_req -- overwriting req-\u003ecomplete while dummy_timer is\nmid-calling it.  The indirect call then jumps to a clobbered pointer,\ncausing a general protection fault / page fault in dummy_timer\n(syzkaller extid faf3a6cf579fc65591ca).  The clobbering write is an\nin-bounds memcpy on a live shared object, so KASAN cannot flag it.\n\nAdd a fifo_req_busy bit covering the shared request's whole lifetime:\nset it in dummy_queue() when the FIFO fast-path takes fifo_req (making\nit the fast-path guard, replacing the list_empty(\u0026fifo_req.queue)\ntest), and clear it after the completion callback has returned, via a\ndummy_giveback() helper used at all four gadget-request giveback\nsites.  The shared slot can no longer be reused until its completion\ncallback has finished.",
  "id": "CVE-2026-68370",
  "modified": "2026-08-12T03:51:16.372863558Z",
  "published": "2026-08-10T12:03:48.320Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/67b589d09a96882d56842dced5698ed8dd06ce45"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d5e5cd3654d2b5359a12ea6586120f05b28634ee"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e239ea91b48180ed48a86ac25643832a02c88456"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e24b33618231034bf01dfaff4fd3409d4b4d5b2e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e2b2740f1242bc70b5b46da2cdbbaa419f490e59"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68370.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68370"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "usb: gadget: dummy_hcd: prevent fifo_req reuse during giveback"
}