CVE-2026-90087 (GCVE-0-2026-90087)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:06 – Updated: 2026-09-17 16:06
VLAI
Title
Bluetooth: do not leak an hci_conn when a second LE connect is rejected
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: do not leak an hci_conn when a second LE connect is rejected create_le_conn_complete() decides whether the failed connection is still pending by comparing it against hci_lookup_le_connect(), which returns the first LE connection in BT_CONNECT. That is the same connection only while at most one is pending. Two can be pending. Connections created on the passive scan path sit in BT_CONNECT with HCI_CONN_SCANNING set and are invisible to hci_lookup_le_connect() until hci_le_create_conn_sync() clears the flag when their command is issued, so the -EBUSY guard in hci_connect_le() does not prevent a second connection from being queued while the first is still on the scan path. Whenever two connections are in BT_CONNECT at once, the lookup may return one connection while create_le_conn_complete() is reporting the failure of the other; the early exit then drops the error and hci_conn_failed() never runs on the connection that failed. The controller also rejects a second HCI_OP_LE_CREATE_CONN issued while another connection creation is still outstanding, per Core Spec Vol 4, Part E. The spec calls for Command Disallowed there; the bcm43438 observed here answers with an LMP/LL error code instead, which bt_to_errno() maps to the -EPROTO (-71) in the log below. The leaked connection stays in BT_CONNECT forever, and because hci_connect_le() refuses to dial while hci_lookup_le_connect() finds anything, every subsequent attempt to reach any peer fails with -EBUSY and no command reaches the controller at all. Seen on a bcm43438 with two BLE peers polled on the same interval (state 5 is BT_CONNECT; both handles are UNSET ones, allocated from the ida above HCI_CONN_HANDLE_MAX): Bluetooth: hci1: Opcode 0x2013 failed: -71 # hcitool con < LE 14:9C:EF:03:68:81 handle 3840 state 5 lm CENTRAL < LE C4:D3:6A:8C:B5:38 handle 3841 state 5 lm CENTRAL A btmon capture across the next ten minutes of connect attempts contains no HCI_OP_LE_CREATE_CONN at all; outgoing LE connections do not recover until the adapter is reset. With this change the same scenario fails the rejected connection cleanly and further connects to both peers go through. Ask about the connection itself instead of about the device.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: c9f73a2178c12fb24d2807634209559d6a836e08 , < 2eafcf310f4e0ad4f387881db01116bbe3cc0b39 (git)
Affected: c9f73a2178c12fb24d2807634209559d6a836e08 , < 7e1e4047200fd7519f9bdfe8a001437715e618b4 (git)
Affected: ee23bb0e4315476413e4e1ed9c486d6f9472294d (git)
Affected: da499d598cb84b45a2aa930dc9213dc9a746a81d (git)
Affected: 5.17.14 , < 5.18 (semver)
Affected: 5.18.3 , < 5.19 (semver)
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Linux Linux Affected: 5.19
Unaffected: 0 , < 5.19 (semver)
Unaffected: 7.2.6 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/hci_sync.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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      "cpeApplicability": [
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          "nodes": [
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                  "vulnerable": true
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                  "versionStartIncluding": "5.18.3",
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              ],
              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: do not leak an hci_conn when a second LE connect is rejected\n\ncreate_le_conn_complete() decides whether the failed connection is\nstill pending by comparing it against hci_lookup_le_connect(), which\nreturns the first LE connection in BT_CONNECT. That is the same\nconnection only while at most one is pending.\n\nTwo can be pending. Connections created on the passive scan path sit\nin BT_CONNECT with HCI_CONN_SCANNING set and are invisible to\nhci_lookup_le_connect() until hci_le_create_conn_sync() clears the\nflag when their command is issued, so the -EBUSY guard in\nhci_connect_le() does not prevent a second connection from being\nqueued while the first is still on the scan path. Whenever two\nconnections are in BT_CONNECT at once, the lookup may return one\nconnection while create_le_conn_complete() is reporting the failure\nof the other; the early exit then drops the error and hci_conn_failed()\nnever runs on the connection that failed.\n\nThe controller also rejects a second HCI_OP_LE_CREATE_CONN issued\nwhile another connection creation is still outstanding, per Core Spec\nVol 4, Part E. The spec calls for Command Disallowed there; the\nbcm43438 observed here answers with an LMP/LL error code instead,\nwhich bt_to_errno() maps to the -EPROTO (-71) in the log below.\n\nThe leaked connection stays in BT_CONNECT forever, and because\nhci_connect_le() refuses to dial while hci_lookup_le_connect() finds\nanything, every subsequent attempt to reach any peer fails with\n-EBUSY and no command reaches the controller at all.\n\nSeen on a bcm43438 with two BLE peers polled on the same interval\n(state 5 is BT_CONNECT; both handles are UNSET ones, allocated from\nthe ida above HCI_CONN_HANDLE_MAX):\n\n  Bluetooth: hci1: Opcode 0x2013 failed: -71\n\n  # hcitool con\n          \u003c LE 14:9C:EF:03:68:81 handle 3840 state 5 lm CENTRAL\n          \u003c LE C4:D3:6A:8C:B5:38 handle 3841 state 5 lm CENTRAL\n\nA btmon capture across the next ten minutes of connect attempts\ncontains no HCI_OP_LE_CREATE_CONN at all; outgoing LE connections\ndo not recover until the adapter is reset. With this change the same\nscenario fails the rejected connection cleanly and further connects\nto both peers go through.\n\nAsk about the connection itself instead of about the device."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-17T16:06:02.872Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/2eafcf310f4e0ad4f387881db01116bbe3cc0b39"
        },
        {
          "url": "https://git.kernel.org/stable/c/7e1e4047200fd7519f9bdfe8a001437715e618b4"
        }
      ],
      "title": "Bluetooth: do not leak an hci_conn when a second LE connect is rejected",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90087",
    "datePublished": "2026-09-17T16:06:02.872Z",
    "dateReserved": "2026-09-11T19:38:34.785Z",
    "dateUpdated": "2026-09-17T16:06:02.872Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "date": "2026-09-25",
      "epss": "0.00198",
      "percentile": "0.08481"
    },
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                "programFiles": [
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              }
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        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: do not leak an hci_conn when a second LE connect is rejected\n\ncreate_le_conn_complete() decides whether the failed connection is\nstill pending by comparing it against hci_lookup_le_connect(), which\nreturns the first LE connection in BT_CONNECT. That is the same\nconnection only while at most one is pending.\n\nTwo can be pending. Connections created on the passive scan path sit\nin BT_CONNECT with HCI_CONN_SCANNING set and are invisible to\nhci_lookup_le_connect() until hci_le_create_conn_sync() clears the\nflag when their command is issued, so the -EBUSY guard in\nhci_connect_le() does not prevent a second connection from being\nqueued while the first is still on the scan path. Whenever two\nconnections are in BT_CONNECT at once, the lookup may return one\nconnection while create_le_conn_complete() is reporting the failure\nof the other; the early exit then drops the error and hci_conn_failed()\nnever runs on the connection that failed.\n\nThe controller also rejects a second HCI_OP_LE_CREATE_CONN issued\nwhile another connection creation is still outstanding, per Core Spec\nVol 4, Part E. The spec calls for Command Disallowed there; the\nbcm43438 observed here answers with an LMP/LL error code instead,\nwhich bt_to_errno() maps to the -EPROTO (-71) in the log below.\n\nThe leaked connection stays in BT_CONNECT forever, and because\nhci_connect_le() refuses to dial while hci_lookup_le_connect() finds\nanything, every subsequent attempt to reach any peer fails with\n-EBUSY and no command reaches the controller at all.\n\nSeen on a bcm43438 with two BLE peers polled on the same interval\n(state 5 is BT_CONNECT; both handles are UNSET ones, allocated from\nthe ida above HCI_CONN_HANDLE_MAX):\n\n  Bluetooth: hci1: Opcode 0x2013 failed: -71\n\n  # hcitool con\n          \u003c LE 14:9C:EF:03:68:81 handle 3840 state 5 lm CENTRAL\n          \u003c LE C4:D3:6A:8C:B5:38 handle 3841 state 5 lm CENTRAL\n\nA btmon capture across the next ten minutes of connect attempts\ncontains no HCI_OP_LE_CREATE_CONN at all; outgoing LE connections\ndo not recover until the adapter is reset. With this change the same\nscenario fails the rejected connection cleanly and further connects\nto both peers go through.\n\nAsk about the connection itself instead of about the device."
          }
        ],
        "id": "CVE-2026-90087",
        "lastModified": "2026-09-17T17:16:59.117",
        "metrics": {},
        "published": "2026-09-17T17:16:59.117",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/2eafcf310f4e0ad4f387881db01116bbe3cc0b39"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/7e1e4047200fd7519f9bdfe8a001437715e618b4"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.