{"api_version":"1","generated_at":"2026-09-25T09:21:55+00:00","cve":"CVE-2026-93209","urls":{"html":"https://cve.report/CVE-2026-93209","api":"https://cve.report/api/cve/CVE-2026-93209.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-93209","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-93209"},"summary":{"title":"Bluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb","description":"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/","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-24 16:17:15","updated_at":"2026-09-24 16:17:15"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/d5eef0747071934a1c080ee617fa4fd3566394c5","name":"https://git.kernel.org/stable/c/d5eef0747071934a1c080ee617fa4fd3566394c5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0337fb092873a4146aa854acb554675b49c8f6b5","name":"https://git.kernel.org/stable/c/0337fb092873a4146aa854acb554675b49c8f6b5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d0b28e9655f4b3195210627577f81883dc1d0162","name":"https://git.kernel.org/stable/c/d0b28e9655f4b3195210627577f81883dc1d0162","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/26f66d5b8a5663af498f7ccc94fc79fb47a2191f","name":"https://git.kernel.org/stable/c/26f66d5b8a5663af498f7ccc94fc79fb47a2191f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d7723320db4c9cb9ec2b9a36140e6c641dd77814","name":"https://git.kernel.org/stable/c/d7723320db4c9cb9ec2b9a36140e6c641dd77814","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f5afdff569a09d1cb8cf19826199d024725576cb","name":"https://git.kernel.org/stable/c/f5afdff569a09d1cb8cf19826199d024725576cb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-93209","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93209","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected da77c1d39bc527b31890bfa0405763c82828defb 0337fb092873a4146aa854acb554675b49c8f6b5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2af7aa6685e22d0dc546b0d27e5f16d3afe211fa d5eef0747071934a1c080ee617fa4fd3566394c5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2615fd9a7c2507eb3be3fbe49dcec88a2f56454a d7723320db4c9cb9ec2b9a36140e6c641dd77814 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2615fd9a7c2507eb3be3fbe49dcec88a2f56454a d0b28e9655f4b3195210627577f81883dc1d0162 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2615fd9a7c2507eb3be3fbe49dcec88a2f56454a 26f66d5b8a5663af498f7ccc94fc79fb47a2191f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2615fd9a7c2507eb3be3fbe49dcec88a2f56454a f5afdff569a09d1cb8cf19826199d024725576cb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ff121be63b761950610f422437aaaef8e075c40 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 18a4c59af609994552c8b39c5438304e070e55c7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1.83 6.1.118 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6.23 6.6.157 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.7.11 6.8 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.8.2 6.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.118 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.157 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.109 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/bluetooth/hci_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"0337fb092873a4146aa854acb554675b49c8f6b5","status":"affected","version":"da77c1d39bc527b31890bfa0405763c82828defb","versionType":"git"},{"lessThan":"d5eef0747071934a1c080ee617fa4fd3566394c5","status":"affected","version":"2af7aa6685e22d0dc546b0d27e5f16d3afe211fa","versionType":"git"},{"lessThan":"d7723320db4c9cb9ec2b9a36140e6c641dd77814","status":"affected","version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","versionType":"git"},{"lessThan":"d0b28e9655f4b3195210627577f81883dc1d0162","status":"affected","version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","versionType":"git"},{"lessThan":"26f66d5b8a5663af498f7ccc94fc79fb47a2191f","status":"affected","version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","versionType":"git"},{"lessThan":"f5afdff569a09d1cb8cf19826199d024725576cb","status":"affected","version":"2615fd9a7c2507eb3be3fbe49dcec88a2f56454a","versionType":"git"},{"status":"affected","version":"4ff121be63b761950610f422437aaaef8e075c40","versionType":"git"},{"status":"affected","version":"18a4c59af609994552c8b39c5438304e070e55c7","versionType":"git"},{"lessThan":"6.1.118","status":"affected","version":"6.1.83","versionType":"semver"},{"lessThan":"6.6.157","status":"affected","version":"6.6.23","versionType":"semver"},{"lessThan":"6.8","status":"affected","version":"6.7.11","versionType":"semver"},{"lessThan":"6.9","status":"affected","version":"6.8.2","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/bluetooth/hci_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.9"},{"lessThan":"6.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.118","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.157","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.109","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.118","versionStartIncluding":"6.1.83","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.157","versionStartIncluding":"6.6.23","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.109","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.9","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","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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/"}],"providerMetadata":{"dateUpdated":"2026-09-24T15:10:32.762Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-93209","datePublished":"2026-09-24T15:10:32.762Z","dateReserved":"2026-09-17T16:02:15.093Z","dateUpdated":"2026-09-24T15:10:32.762Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-24 16:17:15","lastModifiedDate":"2026-09-24 16:17:15","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"93209","Ordinal":"1","Title":"Bluetooth: hci_core: use skb_get() instead of skb_clone() for re","CVE":"CVE-2026-93209","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"93209","Ordinal":"1","NoteData":"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/","Type":"Description","Title":"Bluetooth: hci_core: use skb_get() instead of skb_clone() for re"}]}}}