CVE-2026-90256

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-90256", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.796Z", "datePublished": "2026-09-17T16:07:55.427Z", "dateUpdated": "2026-10-21T12:50:40.034Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:50:40.034Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind\n\nhci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via\nhci_conn_timeout (disc_work) -> hci_proto_disconn_ind ->\nl2cap_disconn_ind. This is UAF if the l2cap_conn is deleted\nconcurrently.\n\ndisc_work is disabled sync in hci_conn_del(), so we cannot take\nhci_dev_lock in disc_work.\n\nFix by using proto_lock to guard l2cap_data, in addition to hdev->lock\nwhich is held in other access paths."}], "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 - l2cap_disconn_ind() is reached from hci_conn_timeout() (hci_conn.disc_work) via hci_proto_disconn_ind() only for ACL_LINK/LE_LINK; hcon->l2cap_data is installed by l2cap_conn_add() from l2cap_connect_cfm()/l2cap_chan_connect() on that HCI connection, so the triggering peer must be in Bluetooth radio range.\nAC:L - The attacker creates the ACL/LE link so l2cap_conn_add() publishes hcon->l2cap_data, then tears it down so l2cap_conn_del() or the last l2cap_conn_put() from l2cap_chan_destroy() (rfcomm_process_rx on rfcomm_run) frees the object while hci_conn_timeout() reads conn->disc_reason; both sides are attacker-driven and retryable.\nPR:N - HCI Connection Complete delivers l2cap_connect_cfm() \u2192 l2cap_conn_add() and later disc_work with no host uid or capability check; SDP (PSM 0x0001) and RFCOMM session close on remote disconnect likewise need no pairing, so an unauthenticated Bluetooth peer is enough.\nUI:N - hci_conn_timeout() runs from hdev->workqueue after the last hci_conn_drop() once the adapter is powered and connectable; incoming ACL/LE setup, RFCOMM/L2CAP teardown, and the disconnect timer need no per-attack user click.\nS:U - The UAF is of the host kmalloc l2cap_conn used by l2cap_disconn_ind() and only corrupts that kernel's Bluetooth/HCI state, with no VM, IOMMU, or sandbox boundary crossing.\nC:H - l2cap_disconn_ind() locklessly loads hcon->l2cap_data and reads conn->disc_reason after l2cap_conn_free() has kfree'd the kmalloc-1k object, so a sprayed replacement discloses kernel heap contents through that dangling pointer.\nI:H - The same freed l2cap_conn can be reallocated under attacker control while hci_conn_timeout() still holds the pointer; heap UAF of this object enables spraying and write/control-flow hijack, and the stale disc_reason is consumed as the HCI abort reason.\nA:H - The syzbot report is a slab-use-after-free read of conn->disc_reason in l2cap_disconn_ind() from the hci_conn_timeout worker, which oopses or panics the kernel when the freed l2cap_conn slab is touched."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/bluetooth/l2cap_core.c"], "versions": [{"version": "efc30877bd4bc85fefe98d80af60fafc86e5775e", "lessThan": "0fa448369c87e20b2aeaeaca0187d698dd61f791", "status": "affected", "versionType": "git"}, {"version": "f87271d21dd4ee83857ca11b94e7b4952749bbae", "lessThan": "7c032b6d48a46634cbd58aaebad2638c00ad3b51", "status": "affected", "versionType": "git"}, {"version": "ab4eedb790cae44313759b50fe47da285e2519d5", "lessThan": "b495a3a9b33bc4e4613e685bf5c96c136caa22d8", "status": "affected", "versionType": "git"}, {"version": "ab4eedb790cae44313759b50fe47da285e2519d5", "lessThan": "2b66c83ff1751d6bd3201b3017206262ab46dc05", "status": "affected", "versionType": "git"}, {"version": "18ab6b6078fa8191ca30a3065d57bf35d5635761", "status": "affected", "versionType": "git"}, {"version": "6.6.84", "lessThan": "6.6.160", "status": "affected", "versionType": "semver"}, {"version": "6.12.20", "lessThan": "6.12.114", "status": "affected", "versionType": "semver"}, {"version": "6.13.8", "lessThan": "6.14", "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_core.c"], "versions": [{"version": "6.14", "status": "affected"}, {"version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.114", "lessThanOrEqual": "6.12.*", "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": "6.6.84", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.20", "versionEndExcluding": "6.12.114"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.2.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13.8"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0fa448369c87e20b2aeaeaca0187d698dd61f791"}, {"url": "https://git.kernel.org/stable/c/7c032b6d48a46634cbd58aaebad2638c00ad3b51"}, {"url": "https://git.kernel.org/stable/c/b495a3a9b33bc4e4613e685bf5c96c136caa22d8"}, {"url": "https://git.kernel.org/stable/c/2b66c83ff1751d6bd3201b3017206262ab46dc05"}], "title": "Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/bluetooth/l2cap_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "0fa448369c87e20b2aeaeaca0187d698dd61f791", "status": "affected", "version": "efc30877bd4bc85fefe98d80af60fafc86e5775e", "versionType": "git"}, {"lessThan": "7c032b6d48a46634cbd58aaebad2638c00ad3b51", "status": "affected", "version": "f87271d21dd4ee83857ca11b94e7b4952749bbae", "versionType": "git"}, {"lessThan": "b495a3a9b33bc4e4613e685bf5c96c136caa22d8", "status": "affected", "version": "ab4eedb790cae44313759b50fe47da285e2519d5", "versionType": "git"}, {"lessThan": "2b66c83ff1751d6bd3201b3017206262ab46dc05", "status": "affected", "version": "ab4eedb790cae44313759b50fe47da285e2519d5", "versionType": "git"}, {"status": "affected", "version": "18ab6b6078fa8191ca30a3065d57bf35d5635761", "versionType": "git"}, {"lessThan": "6.6.160", "status": "affected", "version": "6.6.84", "versionType": "semver"}, {"lessThan": "6.12.114", "status": "affected", "version": "6.12.20", "versionType": "semver"}, {"lessThan": "6.14", "status": "affected", "version": "6.13.8", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/bluetooth/l2cap_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.14"}, {"lessThan": "6.14", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.114", "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: use proto_lock for l2cap_data to fix l2cap_disconn_ind\n\nhci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via\nhci_conn_timeout (disc_work) -> hci_proto_disconn_ind ->\nl2cap_disconn_ind. This is UAF if the l2cap_conn is deleted\nconcurrently.\n\ndisc_work is disabled sync in hci_conn_del(), so we cannot take\nhci_dev_lock in disc_work.\n\nFix by using proto_lock to guard l2cap_data, in addition to hdev->lock\nwhich is held in other access paths."}], "id": "CVE-2026-90256", "lastModified": "2026-10-21T13:20:44.707", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-17T17:17:21.980", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0fa448369c87e20b2aeaeaca0187d698dd61f791"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2b66c83ff1751d6bd3201b3017206262ab46dc05"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7c032b6d48a46634cbd58aaebad2638c00ad3b51"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b495a3a9b33bc4e4613e685bf5c96c136caa22d8"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ab4eedb790cae44313759b50fe47da285e2519d5,b495a3a9b33bc4e4613e685bf5c96c136caa22d8)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ab4eedb790cae44313759b50fe47da285e2519d5,2b66c83ff1751d6bd3201b3017206262ab46dc05)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "efc30877bd4bc85fefe98d80af60fafc86e5775e"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "f87271d21dd4ee83857ca11b94e7b4952749bbae"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "18ab6b6078fa8191ca30a3065d57bf35d5635761"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.6.84,6.7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.12.20,6.13)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.13.8,6.14)"}}], "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": "6.14"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.14)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.6,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "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": "2026-09-19T03:45:17.045327+00:00", "updated": "2026-09-20T03:15:08.051941+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416"]}