{"schema":"threatline.record/2","record":{"id":"CVE-2026-93209","aliases":[],"summary":"Bluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb\n\nBT enable fails intermittently with -ETIMEDOUT (-110).  The kernel log\nshows the HCI Read Local Version command was sent and the firmware\nreplied with status 0x00 (logged by hci_req_cmd_complete() BT_DBG),\nbut the waiter in __hci_cmd_sync_sk() never woke up and timed out\nafter 10 s:\n\n  bluetooth hci0: Opcode 0xfc00              // __hci_cmd_sync_sk\n  bluetooth hci0: opcode 0xfc00 plen 1       // hci_cmd_sync_add\n  bluetooth hci0: skb len 4                  // hci_cmd_sync_alloc\n  bluetooth hci0: length 1                   // hci_req_sync_run\n  Bluetooth: hci0 cmd_cnt 1 cmd queued 1     // hci_cmd_work\n  Bluetooth: hci0 type 1 len 4               // hci_send_frame\n  Bluetooth: opcode 0xfc00 status 0x00       // hci_req_cmd_complete\n  <-- req_skb NULL: req_complete_skb not set,\n      hci_cmd_sync_complete() never called,\n      req_status stays HCI_REQ_PEND            -->\n  <-- 10 s later: wait_event_interruptible_timeout expires -->\n  bluetooth hci0: end: err -110              // __hci_cmd_sync_sk\n\nThe root cause is that hci_send_cmd_sync() clones the sent command\ninto hdev->req_skb so that hci_req_cmd_complete() can locate the\nregistered completion callback.  Under memory pressure this\nskb_clone() fails, leaving hdev->req_skb NULL.  The firmware reply\nis received and processed, but hci_req_cmd_complete() finds NULL\nreq_skb, so hci_cmd_sync_complete() is never called, req_status\nstays HCI_REQ_PEND, and the waiter times out with -ETIMEDOUT.\n\nreq_skb is only used to read bt_cb(skb)->hci callbacks and opcode --\nit is never modified.  Replace skb_clone() with skb_get(), which\nsimply increments the reference count of hdev->sent_cmd without\nallocating new memory and therefore cannot fail.\n\nThis issue was first observed as a use-after-free in ttyport_close()\nwhen ttyport_open() failed, which was investigated in an earlier\npatch series [1].  That investigation led to the discovery of the\ntrue root cause described above.\n\n[1] https://lore.kernel.org/all/20250430111617.1151390-1-quic_cxin@quicinc.com/","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"da77c1d39bc527b31890bfa0405763c82828defb","lessThan":"0337fb092873a4146aa854acb554675b49c8f6b5","status":"affected","versionType":"git"},{"version":"2af7aa6685e22d0dc546b0d27e5f16d3afe211fa","lessThan":"d5eef0747071934a1c080ee617fa4fd3566394c5","status":"affected","versionType":"git"},{"version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","lessThan":"d7723320db4c9cb9ec2b9a36140e6c641dd77814","status":"affected","versionType":"git"},{"version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","lessThan":"d0b28e9655f4b3195210627577f81883dc1d0162","status":"affected","versionType":"git"},{"version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","lessThan":"26f66d5b8a5663af498f7ccc94fc79fb47a2191f","status":"affected","versionType":"git"},{"version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","lessThan":"f5afdff569a09d1cb8cf19826199d024725576cb","status":"affected","versionType":"git"},{"version":"4ff121be63b761950610f422437aaaef8e075c40","status":"affected","versionType":"git"},{"version":"18a4c59af609994552c8b39c5438304e070e55c7","status":"affected","versionType":"git"},{"version":"6.1.83","lessThan":"6.1.118","status":"affected","versionType":"semver"},{"version":"6.6.23","lessThan":"6.6.157","status":"affected","versionType":"semver"},{"version":"6.7.11","lessThan":"6.8","status":"affected","versionType":"semver"},{"version":"6.8.2","lessThan":"6.9","status":"affected","versionType":"semver"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"6.9","status":"affected"},{"version":"0","lessThan":"6.9","status":"unaffected","versionType":"semver"},{"version":"6.1.118","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.109","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.50","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.4","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"0337fb092873a4146aa854acb554675b49c8f6b5","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"26f66d5b8a5663af498f7ccc94fc79fb47a2191f","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6.1.118","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6.6.157","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6.8","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","source_modified_at":"2026-10-19T09:07:21.427Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6.9","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00172,"percentile":0.0631,"score_date":"2026-10-23"},"published_at":"2026-09-24T15:10:32.762Z","modified_at":"2026-10-19T09:07:21.427Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:07:21.427Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-93209","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/0337fb092873a4146aa854acb554675b49c8f6b5"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/d5eef0747071934a1c080ee617fa4fd3566394c5"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/d7723320db4c9cb9ec2b9a36140e6c641dd77814"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/d0b28e9655f4b3195210627577f81883dc1d0162"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/26f66d5b8a5663af498f7ccc94fc79fb47a2191f"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f5afdff569a09d1cb8cf19826199d024725576cb"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:07:21.427Z","content_hash":"4f16a929422fa9b61d3b1ae4bd14ef4d4b1afa06d4c26ddd0df7fe39d56c9ad8"}}