{"id":"CVE-2026-74509","title":"Bluetooth: hci_sync: Fix advertising data UAFs","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Fix advertising data UAFs\n\nhci_find_adv_instance() returns an adv_info pointer that is valid only\nwhile hdev->lock is held.  The advertising comman…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < 565971488191bf54a87a417abafab6ad0de72201","Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < c4cec575a6d6f7c36808a3a0017b0675968bb06b","Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < 95cdcd8c82a501931fd3ae9b3811b0b6da167e94","Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < eb1d8318764de7216e6dbba29a24d69f7ce51348","Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3","Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < cdc36db204ffd97b947d64374cf23a210dc74777","Linux 42fe380baaaccbe635c34ca07b29d19b9ec2498d","Linux >= 5.15.210 < 5.16","Linux 5.17"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:58:37.448836Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:05:51.377Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74509","references":[{"url":"https://git.kernel.org/stable/c/565971488191bf54a87a417abafab6ad0de72201"},{"url":"https://git.kernel.org/stable/c/c4cec575a6d6f7c36808a3a0017b0675968bb06b"},{"url":"https://git.kernel.org/stable/c/95cdcd8c82a501931fd3ae9b3811b0b6da167e94"},{"url":"https://git.kernel.org/stable/c/eb1d8318764de7216e6dbba29a24d69f7ce51348"},{"url":"https://git.kernel.org/stable/c/b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3"},{"url":"https://git.kernel.org/stable/c/cdc36db204ffd97b947d64374cf23a210dc74777"}],"tags":["cve.org"],"epss":0.00249,"epssPercentile":0.15111,"ingestedAt":"2026-10-16T19:46:24.352Z","slug":"CVE-2026-74509","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Fix advertising data UAFs\n\nhci_find_adv_instance() returns an adv_info pointer that is valid only\nwhile hdev->lock is held.  The advertising command-sync paths perform\ninstance lookups without that lock and, in some cases, retain the pointer\nwhile waiting for a controller response.\n\nAn advertising termination event can therefore interleave as follows:\n\n  hci_cmd_sync_work                 hci_rx_work\n  hci_find_adv_instance()\n  __hci_cmd_sync_status()\n    wait for controller reply       hci_dev_lock()\n                                    hci_remove_adv_instance()\n                                      kfree(adv)\n  adv->scan_rsp_changed = false\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300\n  Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88\n  Workqueue: hci0 hci_cmd_sync_work\n  Call Trace:\n   hci_set_ext_scan_rsp_data_sync+0x2e1/0x300\n   hci_schedule_adv_instance_sync+0x390/0x4c0\n   hci_cmd_sync_work+0x173/0x300\n  Allocated by task 87:\n   hci_add_adv_instance+0x538/0xac0\n   add_advertising+0x885/0x1160\n  Freed by task 89:\n   kfree+0x131/0x3c0\n   hci_remove_adv_instance+0x1d8/0x3b0\n   hci_le_ext_adv_term_evt+0x17b/0x730\n\nProtect the instance lookup and payload construction in the extended\nadvertising, scan response, and periodic advertising data paths.  Snapshot\nthe advertising parameters under hdev->lock, but release the lock before\nwaiting for the controller.\n\nClear advertising-data dirty bits before issuing their commands and\nrestore them after a failure using a fresh lookup.  Likewise, update the\nreported transmit power through a fresh lookup after the parameter command\ncompletes.  No adv_info pointer then survives an HCI command wait.\n\n## Affected\n\n- `Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < 565971488191bf54a87a417abafab6ad0de72201`\n- `Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < c4cec575a6d6f7c36808a3a0017b0675968bb06b`\n- `Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < 95cdcd8c82a501931fd3ae9b3811b0b6da167e94`\n- `Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < eb1d8318764de7216e6dbba29a24d69f7ce51348`\n- `Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3`\n- `Linux >= cba6b758711cab946c787f7c15be92cc749b8e1f < cdc36db204ffd97b947d64374cf23a210dc74777`\n- `Linux 42fe380baaaccbe635c34ca07b29d19b9ec2498d`\n- `Linux >= 5.15.210 < 5.16`\n- `Linux 5.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}