{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-93209", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-17T16:02:15.093Z", "datePublished": "2026-09-24T15:10:32.762Z", "dateUpdated": "2026-09-24T15:10:32.762Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-24T15:10:32.762Z"}, "descriptions": [{"lang": "en", "value": "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/"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/bluetooth/hci_core.c"], "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"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/bluetooth/hci_core.c"], "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-rc1", "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": "6.1.83", "versionEndExcluding": "6.1.118"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.23", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.3-rc1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0337fb092873a4146aa854acb554675b49c8f6b5"}, {"url": "https://git.kernel.org/stable/c/d5eef0747071934a1c080ee617fa4fd3566394c5"}, {"url": "https://git.kernel.org/stable/c/d7723320db4c9cb9ec2b9a36140e6c641dd77814"}, {"url": "https://git.kernel.org/stable/c/d0b28e9655f4b3195210627577f81883dc1d0162"}, {"url": "https://git.kernel.org/stable/c/26f66d5b8a5663af498f7ccc94fc79fb47a2191f"}, {"url": "https://git.kernel.org/stable/c/f5afdff569a09d1cb8cf19826199d024725576cb"}], "title": "Bluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb", "x_generator": {"engine": "bippy-1.2.0"}}}}