CVE-2026-90091

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-90091", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.786Z", "datePublished": "2026-09-17T16:06:05.478Z", "dateUpdated": "2026-10-19T08:57:49.423Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:57:49.423Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan\n\nFor L2CAP sockets without owning sk->sk_socket, reading\nl2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() ->\nl2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks,\nbut access in l2cap_sock_cleanup_listen() has unsafe lockless read.\n\n [Task 1] [Task 2 (hdev->workqueue)]\n l2cap_sock_release(parent) l2cap_disconn_cfm\n l2cap_sock_cleanup_listen l2cap_conn_del\n bt_accept_dequeue l2cap_chan_del\n lock_sock(sk) l2cap_sock_teardown_cb\n bt_accept_unlink\n bt_sk(sk)->parent = NULL\n release_sock(sk) ----------------> lock_sock(sk)\n parent = /* NULL */\n lock_sock(sk) <--------------------- release_sock(sk)\n sock_set_flag(sk, SOCK_ZAPPED)\n l2cap_sock_close_cb\n l2cap_sock_kill(sk)\n l2cap_sock_put_chan\n chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL\n l2cap_chan_hold_unless_zero l2cap_put_chan(chan)\n kref_get_unless_zero(&chan->ref)\n\nTask 1 may observe NULL which causes null-ptr-deref.\n\nFix the race by taking lock_sock() in l2cap_sock_kill() to\nsynchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not\nneeded here, l2cap_pi(sk)->chan owns reference if it is non-NULL.\n\nClarify code comments vs. locking."}], "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 - A nearby peer's HCI Disconnection Complete (hci_disconn_complete_evt \u2192 hci_disconn_cfm \u2192 l2cap_disconn_cfm on hdev->rx_work) or L2CAP_DISCONN_REQ (l2cap_disconnect_req) runs l2cap_sock_put_chan on an unaccepted child created by L2CAP_CONN_REQ; the transport is Bluetooth radio range, so Adjacent not Network.\nAC:L - The attacker drives both sides: close() of their listening socket runs l2cap_sock_release \u2192 l2cap_sock_cleanup_listen \u2192 bt_accept_dequeue, while the peer's disconnect concurrently runs l2cap_sock_kill \u2192 l2cap_sock_put_chan on that child without lock_sock; repeating connect/disconnect/close hits the window.\nPR:L - l2cap_sock_create() allows unprivileged SOCK_SEQPACKET/SOCK_STREAM (only SOCK_RAW needs CAP_NET_RAW), and l2cap_validate_bredr_psm() permits dynamic PSM >= 0x1001 without CAP_NET_BIND_SERVICE, so listen()+close() needs only a normal local account; AF_BLUETOOTH is init_net-only (bt_sock_create), not a userns CAP_NET_ADMIN path.\nUI:N - The attacker closes their own listening L2CAP socket and, from a radio they control, sends L2CAP_CONN_REQ then disconnect; no other user must pair, accept, or confirm during the race.\nS:U - The race corrupts the host kernel l2cap_chan stored in l2cap_pi(sk)->chan of the unaccepted child; it does not escape a VM, bypass an IOMMU, or leave the kernel's own authority.\nC:H - cleanup_listen loads l2cap_pi(sk)->chan then calls l2cap_chan_hold_unless_zero(); concurrent l2cap_sock_put_chan plus l2cap_conn_del's final l2cap_chan_put can kfree that object first, so kref_get_unless_zero and later l2cap_chan_lock/__set_chan_timer run on a freed kmalloc l2cap_chan that can be sprayed for disclosure.\nI:H - Winning that UAF lets cleanup_listen take l2cap_chan_lock, arm __set_chan_timer, and l2cap_chan_put on a reclaimed fake chan, corrupting mutex/timer/kref state and invoking chan->ops from sprayed memory for hijack.\nA:H - If cleanup_listen observes the NULL stored by l2cap_sock_put_chan, l2cap_chan_hold_unless_zero() calls kref_get_unless_zero(&c->kref) with c==NULL and oopses; the UAF interleaving likewise panics on poisoned slab or a corrupted chan mutex."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/bluetooth/l2cap.h", "net/bluetooth/l2cap_sock.c"], "versions": [{"version": "b39298044e5534612511a2ff5de03ba5f6e7a820", "lessThan": "827de6bd2865b22aaabd554540def3b8a33018ab", "status": "affected", "versionType": "git"}, {"version": "8c37e4338c801ebb8cee52436c01c41e009f6e87", "lessThan": "7c7ac736b50fa259ed1bdddc18d79523f07c0442", "status": "affected", "versionType": "git"}, {"version": "84e718b6a814edc84159361f9f454a4e92ae91ae", "lessThan": "4f8c63fe0097c9f6ea34409f82f79b3894903d91", "status": "affected", "versionType": "git"}, {"version": "36da806f7fbaee56ad9e81859deec203f9728700", "lessThan": "61d5ddbd524c715b224cbe7e9f01da4e05098b19", "status": "affected", "versionType": "git"}, {"version": "6fef032af0092ed5ccb767239a9ac1bc38c08a40", "lessThan": "32a7bc6e93be36b37fe61f351d312d358195bd61", "status": "affected", "versionType": "git"}, {"version": "6fef032af0092ed5ccb767239a9ac1bc38c08a40", "lessThan": "66d6ef18548ae6d7dd452b84115fc82c0a73a4ea", "status": "affected", "versionType": "git"}, {"version": "733e76e74e406c1d1ddc7369420dd8a47f48bb8a", "status": "affected", "versionType": "git"}, {"version": "6.1.178", "lessThan": "6.1.188", "status": "affected", "versionType": "semver"}, {"version": "6.6.145", "lessThan": "6.6.157", "status": "affected", "versionType": "semver"}, {"version": "6.12.97", "lessThan": "6.12.110", "status": "affected", "versionType": "semver"}, {"version": "6.18.40", "lessThan": "6.18.52", "status": "affected", "versionType": "semver"}, {"version": "7.1.5", "lessThan": "7.2", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/bluetooth/l2cap.h", "net/bluetooth/l2cap_sock.c"], "versions": [{"version": "7.2", "status": "affected"}, {"version": "0", "lessThan": "7.2", "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": "6.1.178", "versionEndExcluding": "6.1.188"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.145", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.97", "versionEndExcluding": "6.12.110"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.40", "versionEndExcluding": "6.18.52"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.2", "versionEndExcluding": "7.2.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.2", "versionEndExcluding": "7.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1.5"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/827de6bd2865b22aaabd554540def3b8a33018ab"}, {"url": "https://git.kernel.org/stable/c/7c7ac736b50fa259ed1bdddc18d79523f07c0442"}, {"url": "https://git.kernel.org/stable/c/4f8c63fe0097c9f6ea34409f82f79b3894903d91"}, {"url": "https://git.kernel.org/stable/c/61d5ddbd524c715b224cbe7e9f01da4e05098b19"}, {"url": "https://git.kernel.org/stable/c/32a7bc6e93be36b37fe61f351d312d358195bd61"}, {"url": "https://git.kernel.org/stable/c/66d6ef18548ae6d7dd452b84115fc82c0a73a4ea"}], "title": "Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/net/bluetooth/l2cap.h", "net/bluetooth/l2cap_sock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "827de6bd2865b22aaabd554540def3b8a33018ab", "status": "affected", "version": "b39298044e5534612511a2ff5de03ba5f6e7a820", "versionType": "git"}, {"lessThan": "7c7ac736b50fa259ed1bdddc18d79523f07c0442", "status": "affected", "version": "8c37e4338c801ebb8cee52436c01c41e009f6e87", "versionType": "git"}, {"lessThan": "4f8c63fe0097c9f6ea34409f82f79b3894903d91", "status": "affected", "version": "84e718b6a814edc84159361f9f454a4e92ae91ae", "versionType": "git"}, {"lessThan": "61d5ddbd524c715b224cbe7e9f01da4e05098b19", "status": "affected", "version": "36da806f7fbaee56ad9e81859deec203f9728700", "versionType": "git"}, {"lessThan": "32a7bc6e93be36b37fe61f351d312d358195bd61", "status": "affected", "version": "6fef032af0092ed5ccb767239a9ac1bc38c08a40", "versionType": "git"}, {"lessThan": "66d6ef18548ae6d7dd452b84115fc82c0a73a4ea", "status": "affected", "version": "6fef032af0092ed5ccb767239a9ac1bc38c08a40", "versionType": "git"}, {"status": "affected", "version": "733e76e74e406c1d1ddc7369420dd8a47f48bb8a", "versionType": "git"}, {"lessThan": "6.1.188", "status": "affected", "version": "6.1.178", "versionType": "semver"}, {"lessThan": "6.6.157", "status": "affected", "version": "6.6.145", "versionType": "semver"}, {"lessThan": "6.12.110", "status": "affected", "version": "6.12.97", "versionType": "semver"}, {"lessThan": "6.18.52", "status": "affected", "version": "6.18.40", "versionType": "semver"}, {"lessThan": "7.2", "status": "affected", "version": "7.1.5", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/net/bluetooth/l2cap.h", "net/bluetooth/l2cap_sock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.2"}, {"lessThan": "7.2", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.188", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.110", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.52", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan\n\nFor L2CAP sockets without owning sk->sk_socket, reading\nl2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() ->\nl2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks,\nbut access in l2cap_sock_cleanup_listen() has unsafe lockless read.\n\n [Task 1] [Task 2 (hdev->workqueue)]\n l2cap_sock_release(parent) l2cap_disconn_cfm\n l2cap_sock_cleanup_listen l2cap_conn_del\n bt_accept_dequeue l2cap_chan_del\n lock_sock(sk) l2cap_sock_teardown_cb\n bt_accept_unlink\n bt_sk(sk)->parent = NULL\n release_sock(sk) ----------------> lock_sock(sk)\n parent = /* NULL */\n lock_sock(sk) <--------------------- release_sock(sk)\n sock_set_flag(sk, SOCK_ZAPPED)\n l2cap_sock_close_cb\n l2cap_sock_kill(sk)\n l2cap_sock_put_chan\n chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL\n l2cap_chan_hold_unless_zero l2cap_put_chan(chan)\n kref_get_unless_zero(&chan->ref)\n\nTask 1 may observe NULL which causes null-ptr-deref.\n\nFix the race by taking lock_sock() in l2cap_sock_kill() to\nsynchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not\nneeded here, l2cap_pi(sk)->chan owns reference if it is non-NULL.\n\nClarify code comments vs. locking."}], "id": "CVE-2026-90091", "lastModified": "2026-10-19T09:18:58.190", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.0, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.1, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-17T17:17:00.563", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/32a7bc6e93be36b37fe61f351d312d358195bd61"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4f8c63fe0097c9f6ea34409f82f79b3894903d91"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/61d5ddbd524c715b224cbe7e9f01da4e05098b19"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/66d6ef18548ae6d7dd452b84115fc82c0a73a4ea"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7c7ac736b50fa259ed1bdddc18d79523f07c0442"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/827de6bd2865b22aaabd554540def3b8a33018ab"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b39298044e5534612511a2ff5de03ba5f6e7a820,827de6bd2865b22aaabd554540def3b8a33018ab)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8c37e4338c801ebb8cee52436c01c41e009f6e87,7c7ac736b50fa259ed1bdddc18d79523f07c0442)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[84e718b6a814edc84159361f9f454a4e92ae91ae,4f8c63fe0097c9f6ea34409f82f79b3894903d91)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[36da806f7fbaee56ad9e81859deec203f9728700,61d5ddbd524c715b224cbe7e9f01da4e05098b19)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[6fef032af0092ed5ccb767239a9ac1bc38c08a40,32a7bc6e93be36b37fe61f351d312d358195bd61)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[6fef032af0092ed5ccb767239a9ac1bc38c08a40,66d6ef18548ae6d7dd452b84115fc82c0a73a4ea)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "733e76e74e406c1d1ddc7369420dd8a47f48bb8a"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.1.178,6.1.188)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.6.145,6.6.157)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.12.97,6.12.110)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.18.40,6.18.52)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[7.1.5,7.2)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "7.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.2)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.1.188,6.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.6.157,6.6.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.110,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.52,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2.6,7.2.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-18T16:30:10.519203+00:00", "updated": "2026-09-20T04:15:17.353279+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-476", "CWE-410"]}