{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "80ea73378af46b0023eb2f400d26c2a60248ffaa"
            },
            {
              "fixed": "a03ccf1ab77380d4c4a3c56552e12de4a83efa21"
            },
            {
              "fixed": "0a554901bd227537f79220443b2b36d585d62893"
            },
            {
              "fixed": "e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b"
            },
            {
              "fixed": "2d696c1ed3468dcb62578a3911e687110d463520"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.15.0"
            },
            {
              "fixed": "6.12.113"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.56"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98739.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: Fix initial port reference race\n\nFor RFCOMM_RELEASE_ONHUP devices, rfcomm_tty_install() and\n__rfcomm_release_dev() both use RFCOMM_TTY_OWNED to decide who drops the\ninitial tty_port reference. The release path tests the bit separately\nfrom the install path setting it, so both can drop that reference.\n\nThe synchronous hangup does not prevent this race: port-\u003etty is not\nassigned until tty_port_open(), after installation. The following\ninterleaving is possible:\n\n  1. Install and release each obtain a reference with rfcomm_dev_get().\n  2. Release observes RFCOMM_TTY_OWNED clear.\n  3. Install sets RFCOMM_TTY_OWNED and drops the initial reference.\n  4. Release drops the same initial reference again.\n  5. TTY cleanup drops its reference and frees the device.\n  6. Release performs its final tty_port_put() on the freed port.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in tty_port_put+0x22/0x190\n  Write of size 4 at addr ffff8881001d3d5c by task poc/92\n\n  Call Trace:\n   tty_port_put+0x22/0x190\n   rfcomm_dev_ioctl+0x1d4/0x1930\n   sock_do_ioctl+0x110/0x260\n   sock_ioctl+0x380/0x590\n   __x64_sys_ioctl+0x134/0x1c0\n\n  Allocated by task 88:\n   rfcomm_dev_ioctl+0x8f6/0x1930\n   sock_do_ioctl+0x110/0x260\n   sock_ioctl+0x380/0x590\n   __x64_sys_ioctl+0x134/0x1c0\n\n  Freed by task 65:\n   kfree+0x131/0x3c0\n   rfcomm_dev_destruct+0x23b/0x2f0\n   release_one_tty+0xc1/0x370\n   process_one_work+0x661/0x1090\n\nUse test_and_set_bit() in both paths so that only the caller that changes\nRFCOMM_TTY_OWNED from clear to set drops the initial reference. Each path\nkeeps its own lookup reference until release or TTY cleanup, preserving\nthe existing callback ordering and error handling.",
  "id": "CVE-2026-98739",
  "modified": "2026-10-20T02:30:54.636228974Z",
  "published": "2026-10-18T15:47:23.653Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0a554901bd227537f79220443b2b36d585d62893"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2d696c1ed3468dcb62578a3911e687110d463520"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a03ccf1ab77380d4c4a3c56552e12de4a83efa21"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98739.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98739"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "Bluetooth: RFCOMM: Fix initial port reference race"
}