{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-68304", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-16T14:48:05.294Z", "datePublished": "2025-12-16T15:06:21.887Z", "dateUpdated": "2026-08-05T12:10:46.641Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:10:46.641Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: lookup hci_conn on RX path on protocol side\n\nThe hdev lock/lookup/unlock/use pattern in the packet RX path doesn't\nensure hci_conn* is not concurrently modified/deleted. This locking\nappears to be leftover from before conn_hash started using RCU\ncommit bf4c63252490b (\"Bluetooth: convert conn hash to RCU\")\nand not clear if it had purpose since then.\n\nCurrently, there are code paths that delete hci_conn* from elsewhere\nthan the ordered hdev->workqueue where the RX work runs in. E.g.\ncommit 5af1f84ed13a (\"Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync\")\nintroduced some of these, and there probably were a few others before\nit. It's better to do the locking so that even if these run\nconcurrently no UAF is possible.\n\nMove the lookup of hci_conn and associated socket-specific conn to\nprotocol recv handlers, and do them within a single critical section\nto cover hci_conn* usage and lookup.\n\nsyzkaller has reported a crash that appears to be this issue:\n\n [Task hdev->workqueue] [Task 2]\n hci_disconnect_all_sync\n l2cap_recv_acldata(hcon)\n hci_conn_get(hcon)\n hci_abort_conn_sync(hcon)\n hci_dev_lock\n hci_dev_lock\n hci_conn_del(hcon)\n v-------------------------------- hci_dev_unlock\n hci_conn_put(hcon)\n conn = hcon->l2cap_data (UAF)" } ], "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 - The flaw is reached through Bluetooth ACL, SCO, or ISO packets, requiring an attacker within radio range of a connectable or advertising target.\nAC:L - An adjacent peer can repeatedly manipulate connection lifecycles while flooding receive traffic, influencing both sides of the race without an uncontrollable prerequisite.\nPR:N - The receive path performs no peer credential or kernel capability check and is reachable before application-level Bluetooth authentication.\nUI:N - No victim action is required once Bluetooth is operating in a connectable or advertising deployment; packet reception and teardown occur automatically.\nS:U - Exploitation compromises the host kernel within the same security authority and does not inherently cross a virtualization or hardware isolation boundary.\nC:H - The freed hci_conn and associated protocol objects contain numerous kernel pointers; reclaiming them can turn stale dereferences into powerful kernel-memory disclosure primitives.\nI:H - The UAF permits writes through reclaimed protocol state, including reference-count, workqueue, reassembly, and socket-related operations, making arbitrary corruption or control-flow hijacking plausible.\nA:H - The UAF has produced KASAN failures and kernel panics, and it can be triggered repeatedly to crash the system." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/bluetooth/hci_core.h", "net/bluetooth/hci_core.c", "net/bluetooth/iso.c", "net/bluetooth/l2cap_core.c", "net/bluetooth/sco.c" ], "versions": [ { "version": "5af1f84ed13a416297ab9ced7537f4d5ae7f329a", "lessThan": "ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93", "status": "affected", "versionType": "git" }, { "version": "5af1f84ed13a416297ab9ced7537f4d5ae7f329a", "lessThan": "79a2d4678ba90bdba577dc3af88cc900d6dcd5ee", "status": "affected", "versionType": "git" }, { "version": "cd55c13bbb3d093ae601aa97e588ed4c1390ebb1", "status": "affected", "versionType": "git" }, { "version": "4d3ca4a9aaf0aa798a6be372dc0fc3a29e37dd57", "status": "affected", "versionType": "git" }, { "version": "80265dd1d944c3f33e52375b5dbe654980bd2688", "status": "affected", "versionType": "git" }, { "version": "6.1.149", "lessThan": "6.2", "status": "affected", "versionType": "semver" }, { "version": "6.4.16", "lessThan": "6.5", "status": "affected", "versionType": "semver" }, { "version": "6.5.3", "lessThan": "6.6", "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/hci_core.h", "net/bluetooth/hci_core.c", "net/bluetooth/iso.c", "net/bluetooth/l2cap_core.c", "net/bluetooth/sco.c" ], "versions": [ { "version": "6.6", "status": "affected" }, { "version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.11", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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", "versionEndExcluding": "6.17.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.18" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.149" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93" }, { "url": "https://git.kernel.org/stable/c/79a2d4678ba90bdba577dc3af88cc900d6dcd5ee" } ], "title": "Bluetooth: hci_core: lookup hci_conn on RX path on protocol side", "x_generator": { "engine": "bippy-1.2.0" } } } }