{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90255", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.796Z", "datePublished": "2026-09-17T16:07:54.775Z", "dateUpdated": "2026-10-19T09:00:31.949Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:00:31.949Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_conn: fix the SCO setup context lifetime\n\nhci_setup_sync() queues a conn_handle_t with a NULL destroy callback, so\nthe context is only freed if hci_enhanced_setup_sync() actually runs. An\nentry that is cancelled instead is leaked, as\n_hci_cmd_sync_cancel_entry() does not release entry->data when there is\nno destroy callback, and hci_cmd_sync_clear() cancels every pending entry\nwhen the controller is unregistered.\n\nThe context also stores a bare hci_conn pointer, so the connection can be\nfreed while the work is queued. The dequeue in hci_conn_del() does not\ncover it either, as it matches on entry->data == conn and entry->data is\nthe wrapper here. Same problem as commit 2f5d635ad590 (\"Bluetooth:\nhci_sync: hold conn in hci_connect_acl/le_sync() callbacks\").\n\nHold the connection and release both from a destroy callback. The\nsubmission failure path drops both, since hci_cmd_sync_submit() does not\ncall the destroy callback when it fails to queue." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - hci_setup_sync() is reached from hci_sco_setup() on ACL HCI Connection Complete (hci_conn_complete_evt) and from hci_sync_conn_complete_evt retrying Enhanced Setup Synchronous Connection on remote error statuses (0x1a, 0x1c, 0x1e, 0x1f); those HCI events arrive over Bluetooth radio, scored Adjacent.\nAC:L - An attacker queues hci_enhanced_setup_sync via hci_setup_sync() (sco_connect->hci_connect_sco->hci_sco_setup, or Sync Conn Complete retries) then frees that SCO hci_conn with hci_conn_del (socket close, hci_disconn_complete_evt, or hci_setup_sync_conn_status). Dequeue matches entry->data==conn but data is the conn_handle_t wrapper, so both sides of the race are attacker-controlled.\nPR:N - A radio-adjacent peer needs no Linux account: HFP/PipeWire stacks cause the host to call hci_setup_sync, and the peer's Disconnection Complete or Synchronous Connection Complete events run hci_conn_del. Locally sco_sock_create() has no capability check (AF_BLUETOOTH is init_net only).\nUI:N - No extra victim action at exploit time: Bluetooth audio stacks automatically open outgoing SCO for a connected HFP/headset, and a local attacker uses their own BTPROTO_SCO sockets rather than inducing another user to mount or open a file.\nS:U - The use-after-free corrupts kernel heap (struct hci_conn) in the host Bluetooth stack and can escalate privileges in that same kernel authority; it does not cross a VM, guest-to-host, or IOMMU boundary.\nC:H - hci_enhanced_setup_sync() reads conn_handle->conn, kfree()s the wrapper, then uses conn (conn->codec, conn->parent, conn->attempt) after only a pointer-compare hci_conn_valid() check, so a freed or slab-reused hci_conn yields arbitrary kernel reads.\nI:H - The same callback writes conn->state, conn->out, and conn->attempt and builds HCI_OP_ENHANCED_SETUP_SYNC_CONN from freed codec fields; struct hci_conn has cleanup/connect_cfm_cb pointers, so slab reuse gives a kernel write and control-flow primitive.\nA:H - Dereferencing a freed hci_conn from hci_cmd_sync_work on req_workqueue causes a kernel oops or panic; UAF availability is High even without full exploitation. Cancelled cmd_sync entries also leak conn_handle_t because destroy was NULL." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/hci_conn.c" ], "versions": [ { "version": "e07a06b4eb417f5271d33ce2240e93c62d98b7b4", "lessThan": "37cfec41365c826d5496ef5d00c9e215eee53aa2", "status": "affected", "versionType": "git" }, { "version": "e07a06b4eb417f5271d33ce2240e93c62d98b7b4", "lessThan": "9a2ba69cebe3fc5a3d4fa8eaaad3c42862723c27", "status": "affected", "versionType": "git" }, { "version": "e07a06b4eb417f5271d33ce2240e93c62d98b7b4", "lessThan": "a661de0ee29d0915c5e924edf91d2be2b4d35bae", "status": "affected", "versionType": "git" }, { "version": "e07a06b4eb417f5271d33ce2240e93c62d98b7b4", "lessThan": "c1fe3c74a89a7749cba3caa0dd91236049c66116", "status": "affected", "versionType": "git" }, { "version": "e07a06b4eb417f5271d33ce2240e93c62d98b7b4", "lessThan": "4d7b1c834d2775b73c65e4888e01f5af8b477fe9", "status": "affected", "versionType": "git" }, { "version": "e07a06b4eb417f5271d33ce2240e93c62d98b7b4", "lessThan": "42de40abe25db9211107af8896d0fd741f10648d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/hci_conn.c" ], "versions": [ { "version": "6.1", "status": "affected" }, { "version": "0", "lessThan": "6.1", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/37cfec41365c826d5496ef5d00c9e215eee53aa2" }, { "url": "https://git.kernel.org/stable/c/9a2ba69cebe3fc5a3d4fa8eaaad3c42862723c27" }, { "url": "https://git.kernel.org/stable/c/a661de0ee29d0915c5e924edf91d2be2b4d35bae" }, { "url": "https://git.kernel.org/stable/c/c1fe3c74a89a7749cba3caa0dd91236049c66116" }, { "url": "https://git.kernel.org/stable/c/4d7b1c834d2775b73c65e4888e01f5af8b477fe9" }, { "url": "https://git.kernel.org/stable/c/42de40abe25db9211107af8896d0fd741f10648d" } ], "title": "Bluetooth: hci_conn: fix the SCO setup context lifetime", "x_generator": { "engine": "bippy-1.2.0" } } } }