{"id":"CVE-2026-90092","state":"PUBLISHED","title":"Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN","description":"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.","publishedAt":"2026-09-17T16:06:06.197Z","updatedAt":"2026-10-19T08:57:50.446Z","severity":{"score":8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0c17c8832562b2aac288e89cefd0f46074f54bcb","status":"affected","lessThan":"bf61a65c6093970e3b50031c4b79ebf3bd411eba","versionType":"git"},{"version":"5105f3e6b2df619c635b5f6a49fac131a36c7952","status":"affected","lessThan":"491e4c60017969b053888029998d2a61f298986a","versionType":"git"},{"version":"c88c185ae0a1067823661b220aeea613df2c127b","status":"affected","lessThan":"2a3a27aaf19bf069720e024ce6fde54e6bf80df9","versionType":"git"},{"version":"1810e42ff6716f320c7269d5850eca48b07b7427","status":"affected","lessThan":"87276dc15b559d32757a43b4415c8445fbae06c4","versionType":"git"},{"version":"2ff1a41a912de8517b4482e946dd951b7d80edbf","status":"affected","lessThan":"c47339e169bf4a0a4cfabb91351471f67744c2bc","versionType":"git"},{"version":"2ff1a41a912de8517b4482e946dd951b7d80edbf","status":"affected","lessThan":"d4bfa78fd67929b62b02013c107973e0c5b7aa9a","versionType":"git"},{"version":"1b1c0da227bf63479bac9982fc8d12df9aaea0fb","status":"affected","versionType":"git"},{"version":"85426e97dc72f2088ba6d27e74cd58c3fbd43e31","status":"affected","versionType":"git"},{"version":"a2dcf1a61d056aef15b63c6eae9441344d624389","status":"affected","versionType":"git"},{"version":"6.1.175","status":"affected","lessThan":"6.1.188","versionType":"semver"},{"version":"6.6.140","status":"affected","lessThan":"6.6.157","versionType":"semver"},{"version":"6.12.88","status":"affected","lessThan":"6.12.110","versionType":"semver"},{"version":"6.18.30","status":"affected","lessThan":"6.18.52","versionType":"semver"},{"version":"5.10.258","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.209","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"7.0.7","status":"affected","lessThan":"7.1","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/l2cap_sock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/l2cap_sock.c"]}],"references":["https://git.kernel.org/stable/c/bf61a65c6093970e3b50031c4b79ebf3bd411eba","https://git.kernel.org/stable/c/491e4c60017969b053888029998d2a61f298986a","https://git.kernel.org/stable/c/2a3a27aaf19bf069720e024ce6fde54e6bf80df9","https://git.kernel.org/stable/c/87276dc15b559d32757a43b4415c8445fbae06c4","https://git.kernel.org/stable/c/c47339e169bf4a0a4cfabb91351471f67744c2bc","https://git.kernel.org/stable/c/d4bfa78fd67929b62b02013c107973e0c5b7aa9a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90092.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90092","state":"PUBLISHED","datePublished":"2026-09-17T16:06:06.197Z","dateUpdated":"2026-10-19T08:57:50.446Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.786Z"},"containers":{"cna":{"title":"Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0c17c8832562b2aac288e89cefd0f46074f54bcb","status":"affected","lessThan":"bf61a65c6093970e3b50031c4b79ebf3bd411eba","versionType":"git"},{"version":"5105f3e6b2df619c635b5f6a49fac131a36c7952","status":"affected","lessThan":"491e4c60017969b053888029998d2a61f298986a","versionType":"git"},{"version":"c88c185ae0a1067823661b220aeea613df2c127b","status":"affected","lessThan":"2a3a27aaf19bf069720e024ce6fde54e6bf80df9","versionType":"git"},{"version":"1810e42ff6716f320c7269d5850eca48b07b7427","status":"affected","lessThan":"87276dc15b559d32757a43b4415c8445fbae06c4","versionType":"git"},{"version":"2ff1a41a912de8517b4482e946dd951b7d80edbf","status":"affected","lessThan":"c47339e169bf4a0a4cfabb91351471f67744c2bc","versionType":"git"},{"version":"2ff1a41a912de8517b4482e946dd951b7d80edbf","status":"affected","lessThan":"d4bfa78fd67929b62b02013c107973e0c5b7aa9a","versionType":"git"},{"version":"1b1c0da227bf63479bac9982fc8d12df9aaea0fb","status":"affected","versionType":"git"},{"version":"85426e97dc72f2088ba6d27e74cd58c3fbd43e31","status":"affected","versionType":"git"},{"version":"a2dcf1a61d056aef15b63c6eae9441344d624389","status":"affected","versionType":"git"},{"version":"6.1.175","status":"affected","lessThan":"6.1.188","versionType":"semver"},{"version":"6.6.140","status":"affected","lessThan":"6.6.157","versionType":"semver"},{"version":"6.12.88","status":"affected","lessThan":"6.12.110","versionType":"semver"},{"version":"6.18.30","status":"affected","lessThan":"6.18.52","versionType":"semver"},{"version":"5.10.258","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.209","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"7.0.7","status":"affected","lessThan":"7.1","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/l2cap_sock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/l2cap_sock.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:57:50.446Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}