FKIE_CVE-2026-99008

Vulnerability from fkie_nvd - Published: 2026-10-23 13:17 - Updated: 2026-10-23 13:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: Fix NULL tty_dev dereference in rfcomm_dev_shutdown syzbot hit a NULL pointer dereference in rfcomm_dev_shutdown() when an RFCOMM tty is closed. rfcomm_dev_add() puts the new device on rfcomm_dev_list first and only then registers the tty device and saves it in dev->tty_dev. If that registration fails, dev->tty_dev is never set at all. The device can be looked up in the meantime, so an open() of /dev/rfcommN gets through rfcomm_tty_install() and attaches to it. When that tty is closed again, rfcomm_dev_shutdown() uses dev->tty_dev without checking it: Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] RIP: 0010:rfcomm_dev_shutdown+0x48/0xb0 net/bluetooth/rfcomm/tty.c:131 Call Trace: tty_port_shutdown+0x1bf/0x220 drivers/tty/tty_port.c:372 tty_port_close+0x4e/0x150 drivers/tty/tty_port.c:705 tty_release+0x359/0x1670 drivers/tty/tty_io.c:1718 __fput+0x418/0xa50 fs/file_table.c:512 rfcomm_dev_destruct() already copes with a NULL dev->tty_dev. Add the same check to rfcomm_dev_shutdown(), so the tty device is only moved when it was actually registered.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/08e90633377f1b2567ab5ad6810b74c552246a07
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3fd5164bdb04635caa7942ddb554b0ec699a9433
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a661f401f83b8462f2d424e0a1a72b7681e92ea2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d0aef0b0374678153244f162df507106d728af39
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d5c372ad03330f02962d4860df4d355ab25487df
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/rfcomm/tty.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d5c372ad03330f02962d4860df4d355ab25487df",
              "status": "affected",
              "version": "cad348a17e170451ea8688b532a6ca3e98c63b60",
              "versionType": "git"
            },
            {
              "lessThan": "3fd5164bdb04635caa7942ddb554b0ec699a9433",
              "status": "affected",
              "version": "cad348a17e170451ea8688b532a6ca3e98c63b60",
              "versionType": "git"
            },
            {
              "lessThan": "a661f401f83b8462f2d424e0a1a72b7681e92ea2",
              "status": "affected",
              "version": "cad348a17e170451ea8688b532a6ca3e98c63b60",
              "versionType": "git"
            },
            {
              "lessThan": "d0aef0b0374678153244f162df507106d728af39",
              "status": "affected",
              "version": "cad348a17e170451ea8688b532a6ca3e98c63b60",
              "versionType": "git"
            },
            {
              "lessThan": "08e90633377f1b2567ab5ad6810b74c552246a07",
              "status": "affected",
              "version": "cad348a17e170451ea8688b532a6ca3e98c63b60",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/rfcomm/tty.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.12"
            },
            {
              "lessThan": "3.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: Fix NULL tty_dev dereference in rfcomm_dev_shutdown\n\nsyzbot hit a NULL pointer dereference in rfcomm_dev_shutdown() when an\nRFCOMM tty is closed.\n\nrfcomm_dev_add() puts the new device on rfcomm_dev_list first and only\nthen registers the tty device and saves it in dev-\u003etty_dev. If that\nregistration fails, dev-\u003etty_dev is never set at all. The device can be\nlooked up in the meantime, so an open() of /dev/rfcommN gets through\nrfcomm_tty_install() and attaches to it. When that tty is closed again,\nrfcomm_dev_shutdown() uses dev-\u003etty_dev without checking it:\n\n  Oops: general protection fault, probably for non-canonical address\n  KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]\n  RIP: 0010:rfcomm_dev_shutdown+0x48/0xb0 net/bluetooth/rfcomm/tty.c:131\n  Call Trace:\n   tty_port_shutdown+0x1bf/0x220 drivers/tty/tty_port.c:372\n   tty_port_close+0x4e/0x150 drivers/tty/tty_port.c:705\n   tty_release+0x359/0x1670 drivers/tty/tty_io.c:1718\n   __fput+0x418/0xa50 fs/file_table.c:512\n\nrfcomm_dev_destruct() already copes with a NULL dev-\u003etty_dev. Add the\nsame check to rfcomm_dev_shutdown(), so the tty device is only moved\nwhen it was actually registered."
    }
  ],
  "id": "CVE-2026-99008",
  "lastModified": "2026-10-23T13:17:23.290",
  "metrics": {},
  "published": "2026-10-23T13:17:23.290",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/08e90633377f1b2567ab5ad6810b74c552246a07"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3fd5164bdb04635caa7942ddb554b0ec699a9433"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a661f401f83b8462f2d424e0a1a72b7681e92ea2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d0aef0b0374678153244f162df507106d728af39"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5c372ad03330f02962d4860df4d355ab25487df"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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