FKIE_CVE-2026-99239

Vulnerability from fkie_nvd - Published: 2026-11-02 16:17 - Updated: 2026-11-03 20:18
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: refuse __l2cap_chan_add if chan already has conn l2cap_chan may be linked to l2cap_conn at most once. This is assumed in several places, eg l2cap_chan_del cleanup. There is a TOCTOU race where the invariant is violated: [Task 1] [Task 2] l2cap_chan_connect l2cap_sock_bind l2cap_chan_lock lock_sock l2cap_state_change if (sk->sk_state != BT_OPEN) chan->state = BT_CONNECT l2cap_sock_state_change_cb chan->state = BT_BOUND sk->sk_state = BT_BOUND lock_sock <------------------ release_sock sk->sk_state = BT_CONNECT l2cap_sock_connect() does not check sk->sk_state, so since chan->state is now BT_BOUND, subsequent connect() ends up with second __l2cap_chan_add. Explicitly document and check the invariant in __l2cap_chan_add with WARN_ON_ONCE. The only callsite where it could be hit is l2cap_chan_connect, so add pre-check there to avoid relying on chan->state. chan->state read/write is not properly guarded currently so there can be other TOCTOUC problems. Add l2cap_lock_chan in l2cap_sock_bind() to guard chan->state write.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/10c705dd706aa93164ba41f2566f15206d6c178e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/52fe88e4ef87311eee32b45c65603e7c69e75e7d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/73820561d8cbfd3364a29b8fa77f1707f26029da
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/820579652b24ce277e0097cd65b42bd9b7b8bf07
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/85cc289eb08afa975375f838187369e68b429ee0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/86b55991d3cd690e73c5ef8d20b75ae4905b357a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d3afd7803f9bc2a8c4270199497b60158b2fc647
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e618d928ec7f88cbeadfa3542adcac40f474e629
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_core.c",
            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "85cc289eb08afa975375f838187369e68b429ee0",
              "status": "affected",
              "version": "8f90405a4a6f1f1880dc07996b47bf57c712bd8a",
              "versionType": "git"
            },
            {
              "lessThan": "820579652b24ce277e0097cd65b42bd9b7b8bf07",
              "status": "affected",
              "version": "32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b",
              "versionType": "git"
            },
            {
              "lessThan": "e618d928ec7f88cbeadfa3542adcac40f474e629",
              "status": "affected",
              "version": "8922c7940bae9ce4b1736dddb6362370793835c2",
              "versionType": "git"
            },
            {
              "lessThan": "fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2",
              "status": "affected",
              "version": "91047a4396a8b1857a6f712a90cf33ec0012b189",
              "versionType": "git"
            },
            {
              "lessThan": "52fe88e4ef87311eee32b45c65603e7c69e75e7d",
              "status": "affected",
              "version": "0b0e2bf39cf99e458d991b9df253727e036a7d7d",
              "versionType": "git"
            },
            {
              "lessThan": "10c705dd706aa93164ba41f2566f15206d6c178e",
              "status": "affected",
              "version": "d3b739db5dc6f688a60d56da872fabaf65246032",
              "versionType": "git"
            },
            {
              "lessThan": "73820561d8cbfd3364a29b8fa77f1707f26029da",
              "status": "affected",
              "version": "b66774b48dd98f07254951f74ea6f513efe7ff8b",
              "versionType": "git"
            },
            {
              "lessThan": "d3afd7803f9bc2a8c4270199497b60158b2fc647",
              "status": "affected",
              "version": "b66774b48dd98f07254951f74ea6f513efe7ff8b",
              "versionType": "git"
            },
            {
              "lessThan": "86b55991d3cd690e73c5ef8d20b75ae4905b357a",
              "status": "affected",
              "version": "b66774b48dd98f07254951f74ea6f513efe7ff8b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "50c38d9f42a529691e4e67ea9cedf4f0bfc8d277",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.273",
              "status": "affected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThan": "5.15.224",
              "status": "affected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThan": "6.1.191",
              "status": "affected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThan": "6.6.161",
              "status": "affected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12.115",
              "status": "affected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThan": "6.18.60",
              "status": "affected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThan": "7.2",
              "status": "affected",
              "version": "7.1.4",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_core.c",
            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.2"
            },
            {
              "lessThan": "7.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.273",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.224",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.161",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.115",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.60",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.3.*",
              "status": "unaffected",
              "version": "7.3.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.4-rc1",
              "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: L2CAP: refuse __l2cap_chan_add if chan already has conn\n\nl2cap_chan may be linked to l2cap_conn at most once. This is assumed in\nseveral places, eg l2cap_chan_del cleanup.\n\nThere is a TOCTOU race where the invariant is violated:\n\n    [Task 1]                          [Task 2]\n    l2cap_chan_connect                l2cap_sock_bind\n      l2cap_chan_lock                   lock_sock\n      l2cap_state_change                if (sk-\u003esk_state != BT_OPEN)\n        chan-\u003estate = BT_CONNECT\n        l2cap_sock_state_change_cb      chan-\u003estate = BT_BOUND\n                                        sk-\u003esk_state = BT_BOUND\n          lock_sock \u003c------------------ release_sock\n          sk-\u003esk_state = BT_CONNECT\n\nl2cap_sock_connect() does not check sk-\u003esk_state, so since chan-\u003estate\nis now BT_BOUND, subsequent connect() ends up with second\n__l2cap_chan_add.\n\nExplicitly document and check the invariant in __l2cap_chan_add with\nWARN_ON_ONCE. The only callsite where it could be hit is\nl2cap_chan_connect, so add pre-check there to avoid relying on\nchan-\u003estate. chan-\u003estate read/write is not properly guarded currently so\nthere can be other TOCTOUC problems.\n\nAdd l2cap_lock_chan in l2cap_sock_bind() to guard chan-\u003estate write."
    }
  ],
  "id": "CVE-2026-99239",
  "lastModified": "2026-11-03T20:18:30.280",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-11-02T16:17:49.540",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/10c705dd706aa93164ba41f2566f15206d6c178e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/52fe88e4ef87311eee32b45c65603e7c69e75e7d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/73820561d8cbfd3364a29b8fa77f1707f26029da"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/820579652b24ce277e0097cd65b42bd9b7b8bf07"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/85cc289eb08afa975375f838187369e68b429ee0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/86b55991d3cd690e73c5ef8d20b75ae4905b357a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d3afd7803f9bc2a8c4270199497b60158b2fc647"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e618d928ec7f88cbeadfa3542adcac40f474e629"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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