{"cve":"CVE-2026-93247","nvd":{"published":"2026-09-24T16:17:20.803","modified":"2026-10-19T10:17:15.900","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: mgmt: fix 'hdev->discovery.uuids' NULL dereference\n\n'uuid_count' member of struct 'discovery_state' is assigned and read\nwithout any locks, so there is a chance of situation when\nuuid_count != 0, but uuids is NULL and there will be NULL pointer\ndereference.\n\nPossible race:\n'hci_update_passive_scan_sync'\n  'hci_discovery_filter_clear'\n    hdev->discovery.uuid_count = 0;\n      <----------------------preempted----------------------------->\n                        'start_service_discovery'\n                          // Set uuid_count to value != 0\n                          hdev->discovery.uuid_count = uuid_count;\n                          hdev->discovery.uuids = kmemdup(...);\n      <----------------------preempted----------------------------->\n    spin_lock(&hdev->discovery.lock);\n    kfree(hdev->discovery.uuids);\n    hdev->discovery.uuids = NULL;\n    spin_unlock(&hdev->discovery.lock);\n\nNow uuids == NULL and uuid_count != 0.\nSo 'mgmt_device_found' -> 'is_filter_match' -> 'eir_has_uuids' receives\nnon consistent discovery state, where NULL dereference of uuids happens.\n\nTo fix it let's add discovery.lock around every read/write of uuid_count,\nuuids pair of struct members. It is also important to assign uuid_count\nvalue only after success kmemdup() allocation in\nstart_service_discovery(), otherwise uuids is NULL, because kmemdup failed,\nbut uuid_count is already assigned to non zero value.\n\nThe following panic happens:\n\n[ ] ------------[ cut here ]------------\n[ ] Unable to handle kernel NULL pointer dereference at virtual\naddress 0000000000000000\n[ ] Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP\n[ ] CPU: 0 PID: 15056 Comm: kworker/u9:2\n[ ] Workqueue: hci0 hci_rx_work\n[ ] pstate: 10400009 (nzcV daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n[ ] pc : eir_has_uuids+0x2d8/0x590\n[ ] lr : is_filter_match+0x258/0x320\n...\n[ ] Call trace:\n[ ]  eir_has_uuids+0x2d8/0x590\n[ ]  is_filter_match+0x258/0x320\n[ ]  mgmt_device_found+0x5b0/0xafc\n[ ]  process_adv_report.part.0+0x8c8/0xf14\n[ ]  hci_le_adv_report_evt+0x338/0x3f0\n[ ]  hci_le_meta_evt+0x1f0/0x4c8\n[ ]  hci_event_packet+0x440/0xc9c\n[ ]  hci_rx_work+0x44c/0xaf8\n[ ]  process_one_work+0x54c/0x103c\n[ ]  worker_thread+0x6c4/0x10c4\n[ ]  kthread+0x274/0x2ec\n[ ]  ret_from_fork+0x10/0x20\n[ ] Code: 14000004 91004021 eb14003f 54000180 (f9400024)\n[ ] ---[ end trace 0000000000000000 ]---","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/18fda026a13c5abd6c1e0dfd3549f490b73378fb","https://git.kernel.org/stable/c/59eecbe2f2f38d8f3e1104bd11da97f9a2c58998","https://git.kernel.org/stable/c/bbd262d2d750b67b15a5e1008d3848309c87e7a7","https://git.kernel.org/stable/c/c3f63610bceaa182e4683b23cc47baf36b5f1496","https://git.kernel.org/stable/c/ee2135a14fb2a3e176149122764d293f0796b1eb"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-93247","score":0.00206,"percentile":0.10492,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}