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Bluetooth: RFCOMM: connect the session socket without rfcomm_mutex

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: connect the session socket without rfcomm_mutex An RFCOMM connect() issued while a BR/EDR link is being authenticated makes lockdep report a circular dependency, and the reported cycle is a real AB/BA between rfcomm_mutex and hdev->lock. rfcomm_security_cfm() is called from the HCI event path, which already holds hdev->lock: hci_rx_work() hci_event_packet() hci_cc_read_enc_key_size() [hdev->lock] hci_encrypt_cfm() [hci_cb_list_lock] rfcomm_security_cfm() [rfcomm_mutex] while an RFCOMM connect() from userspace takes the same two locks the other way round: rfcomm_sock_connect() rfcomm_dlc_open() [rfcomm_mutex] __rfcomm_dlc_open() rfcomm_session_create() kernel_connect() l2cap_sock_connect() l2cap_chan_connect() [hdev->lock] WARNING: possible circular locking dependency detected kworker/u131:1/1128 is trying to acquire lock: rfcomm_mutex, at: rfcomm_security_cfm+0x31/0x3e0 [rfcomm] but task is already holding lock: hci_cb_list_lock, at: hci_cc_read_enc_key_size+0x1d2/0xcc0 Chain exists of: rfcomm_mutex --> &hdev->lock --> hci_cb_list_lock hci_auth_complete_evt() and hci_encrypt_change_evt() reach the callback the same way. Both orders have to be seen in the same boot, which is why a BR/EDR connection alone is not enough to show it: a session set up by the remote side is created by rfcomm_accept_connection() in krfcommd, which calls kernel_accept() and never takes hdev->lock under rfcomm_mutex.

Announced Source revision 1
Original source ↗

CVE-2026-99009

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-99009

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
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Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "82425b14f0fb22e46cfddc56d6465570f5ed0ce6",
        "lessThan": "4dc3d5a004b8fd59f3c905631dbb18cb601b1b41",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "1b7841ffad08e911e8c4b9470f3fa08423568940",
        "lessThan": "d2206e8c78be69d21d4f5343c3e99fbaeef41cbb",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "946d76db77ee5f922968ce558629ae47b381e3fc",
        "lessThan": "cc7732b8549ecb6f02457edeb8db1f6d255e381c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fbf7961964a6e93360179f64712320ae9a1e9577",
        "lessThan": "f492de11b325446b0b11bc2eb86e1f546eaa61b6",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "759c185d0bbdb131357408f50b8735e04ed3caff",
        "lessThan": "ac022970e9fb0a5f7e7d1f6c8e104c1ed924dd1c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "62ce8b33eb238cf18c15207332fbdc26d858f592",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "3873f3449701b3dc98cba577923be6493598e7a1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "7ded3264106418c6456ccceaafd9fda596ce12c3",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5.10.270",
        "lessThan": "5.11",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "5.15.221",
        "lessThan": "5.16",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.1.188",
        "lessThan": "6.2",
        "versionType": "semver"
      }
    ],
    "programFiles": [
      "include/net/bluetooth/rfcomm.h",
      "net/bluetooth/rfcomm/core.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.6.157",
        "lessThan": "6.6.160",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.12.109",
        "lessThan": "6.12.114",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "6.18.50",
        "lessThan": "6.18.58",
        "versionType": "semver"
      },
      {
        "status": "affected",
        "version": "7.2.4",
        "lessThan": "7.2.11",
        "versionType": "semver"
      }
    ],
    "programFiles": [
      "include/net/bluetooth/rfcomm.h",
      "net/bluetooth/rfcomm/core.c"
    ],
    "defaultStatus": "unaffected"
  }
]
Related CVEs
CVE-2026-99009

Source reference: /cveMetadata/cveId

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Event
#52851 · Revision 1
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