{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90092", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.786Z", "datePublished": "2026-09-17T16:06:06.197Z", "dateUpdated": "2026-10-19T08:57:50.446Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:57:50.446Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: reject accept queue add unless BT_LISTEN\n\nNew sk should not be added to parent socket accept queue after last\nl2cap_sock_cleanup_listen() has run in l2cap_sock_teardown_cb() and\nstate set to BT_CLOSED, as that can result to UAF on dereferencing the\ndangling parent reference.\n\nl2cap_sock_new_connection_cb() may race with parent l2cap_chan teardown,\ndue to chan->state accessed without consistent locking:\n\n [Task 1] [Task 2]\n l2cap_sock_release(parent) l2cap_connect\n l2cap_sock_shutdown pchan = l2cap_global_chan_by_psm\n l2cap_chan_lock(pchan)\n l2cap_chan_close\n l2cap_sock_teardown_cb\n pchan->state = BT_CLOSED\n l2cap_chan_unlock(pchan) ------> l2cap_chan_lock(pchan)\n l2cap_new_connection\n l2cap_sock_new_connection_cb\n l2cap_chan_lock(pchan) <-------- l2cap_chan_unlock(pchan)\n l2cap_sock_kill(parent) /* bt_sk(sk)->parent dangling */\n\nFix by adding check for sk_state == BT_LISTEN after acquiring sk lock in\nl2cap_sock_new_connection_cb(). Add lock_sock() around sk_state writes\nwhere missing, to avoid data races.\n\nAlthough the data races on pchan->state should be fixed too, this\ndefensive sk_state check probably makes sense in any case." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - The UAF is reached when a remote peer's L2CAP Connection Request (L2CAP_CONN_REQ, L2CAP_LE_CONN_REQ, or L2CAP_ECRED_CONN_REQ) is delivered via hci_acldata_packet() → l2cap_recv_acldata() → l2cap_recv_frame() into l2cap_connect()/l2cap_le_connect_req(), which calls l2cap_new_connection() → l2cap_sock_new_connection_cb(). Bluetooth radio range is adjacent.\nAC:L - The race is between the attacker's close() of their listening socket (l2cap_sock_release() → l2cap_sock_teardown_cb() setting BT_CLOSED, then l2cap_sock_kill()) and an in-flight L2CAP_CONN_REQ that already passed l2cap_global_chan_by_psm(BT_LISTEN) and is waiting on the chan lock. The attacker owns both sides and can retry.\nPR:L - Triggering the parent-free half requires owning the listener: l2cap_sock_create() has no capability check for SOCK_SEQPACKET/SOCK_STREAM, and l2cap_validate_le_psm()/l2cap_validate_bredr_psm() allow dynamic PSMs (≥0x0080 LE, ≥0x1001 BR/EDR) without CAP_NET_BIND_SERVICE. smp_sufficient_security() returns true at default BT_SECURITY_LOW, so the LE connect side needs no pairing.\nUI:N - The attacker close()s their own L2CAP listen fd and sends L2CAP Connection Requests from a radio they control; no victim pairing prompt, mount, or other user action is required to reach l2cap_sock_new_connection_cb() or the later l2cap_sock_ready_cb() dereference.\nS:U - The use-after-free corrupts the listening kernel struct sock in kmalloc-2k and stays within the kernel's own security authority; it is not a VM, IOMMU, or sandbox escape.\nC:H - syzbot KASAN reports a slab-use-after-free Read in l2cap_sock_ready_cb() of the parent sock already freed by l2cap_sock_release()→__sk_destruct(). The child's dangling bt_sk(sk)->parent is then used to load parent->sk_data_ready from the freed kmalloc-2k object, so spraying that cache discloses kernel memory.\nI:H - l2cap_sock_ready_cb() calls parent->sk_data_ready(parent) on the freed sock, hijacking a function pointer, and l2cap_sock_teardown_cb() may still run bt_accept_unlink() which list_del_init()s and writes sk_ack_backlog on that same freed parent, giving a write/CFI primitive.\nA:H - The same dangling-parent load in l2cap_sock_ready_cb() is a confirmed slab-use-after-free (syzbot KASAN splat from l2cap_info_timeout()→l2cap_chan_ready()) that oopses or panics the kernel even without a completed exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/l2cap_sock.c" ], "versions": [ { "version": "0c17c8832562b2aac288e89cefd0f46074f54bcb", "lessThan": "bf61a65c6093970e3b50031c4b79ebf3bd411eba", "status": "affected", "versionType": "git" }, { "version": "5105f3e6b2df619c635b5f6a49fac131a36c7952", "lessThan": "491e4c60017969b053888029998d2a61f298986a", "status": "affected", "versionType": "git" }, { "version": "c88c185ae0a1067823661b220aeea613df2c127b", "lessThan": "2a3a27aaf19bf069720e024ce6fde54e6bf80df9", "status": "affected", "versionType": "git" }, { "version": "1810e42ff6716f320c7269d5850eca48b07b7427", "lessThan": "87276dc15b559d32757a43b4415c8445fbae06c4", "status": "affected", "versionType": "git" }, { "version": "2ff1a41a912de8517b4482e946dd951b7d80edbf", "lessThan": "c47339e169bf4a0a4cfabb91351471f67744c2bc", "status": "affected", "versionType": "git" }, { "version": "2ff1a41a912de8517b4482e946dd951b7d80edbf", "lessThan": "d4bfa78fd67929b62b02013c107973e0c5b7aa9a", "status": "affected", "versionType": "git" }, { "version": "1b1c0da227bf63479bac9982fc8d12df9aaea0fb", "status": "affected", "versionType": "git" }, { "version": "85426e97dc72f2088ba6d27e74cd58c3fbd43e31", "status": "affected", "versionType": "git" }, { "version": "a2dcf1a61d056aef15b63c6eae9441344d624389", "status": "affected", "versionType": "git" }, { "version": "6.1.175", "lessThan": "6.1.188", "status": "affected", "versionType": "semver" }, { "version": "6.6.140", "lessThan": "6.6.157", "status": "affected", "versionType": "semver" }, { "version": "6.12.88", "lessThan": "6.12.110", "status": "affected", "versionType": "semver" }, { "version": "6.18.30", "lessThan": "6.18.52", "status": "affected", "versionType": "semver" }, { "version": "5.10.258", "lessThan": "5.11", "status": "affected", "versionType": "semver" }, { "version": "5.15.209", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "7.0.7", "lessThan": "7.1", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/l2cap_sock.c" ], "versions": [ { "version": "7.1", "status": "affected" }, { "version": "0", "lessThan": "7.1", "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": "6.1.175", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.140", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.88", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.30", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0.7" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bf61a65c6093970e3b50031c4b79ebf3bd411eba" }, { "url": "https://git.kernel.org/stable/c/491e4c60017969b053888029998d2a61f298986a" }, { "url": "https://git.kernel.org/stable/c/2a3a27aaf19bf069720e024ce6fde54e6bf80df9" }, { "url": "https://git.kernel.org/stable/c/87276dc15b559d32757a43b4415c8445fbae06c4" }, { "url": "https://git.kernel.org/stable/c/c47339e169bf4a0a4cfabb91351471f67744c2bc" }, { "url": "https://git.kernel.org/stable/c/d4bfa78fd67929b62b02013c107973e0c5b7aa9a" } ], "title": "Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN", "x_generator": { "engine": "bippy-1.2.0" } } } }