{"id":"CVE-2026-74509","summary":"Bluetooth: hci_sync: Fix advertising data UAFs","details":"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-\u003elock 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-\u003escan_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-\u003elock, 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.","modified":"2026-10-24T02:30:41.941074878Z","published":"2026-08-15T12:27:31.896Z","related":["ALSA-2026:85321","ALSA-2026:86033","SUSE-SU-2026:23477-1","SUSE-SU-2026:23481-1","SUSE-SU-2026:23528-1","SUSE-SU-2026:23529-1","SUSE-SU-2026:4120-1","SUSE-SU-2026:4254-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74509.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/565971488191bf54a87a417abafab6ad0de72201"},{"type":"WEB","url":"https://git.kernel.org/stable/c/95cdcd8c82a501931fd3ae9b3811b0b6da167e94"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c4cec575a6d6f7c36808a3a0017b0675968bb06b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cdc36db204ffd97b947d64374cf23a210dc74777"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eb1d8318764de7216e6dbba29a24d69f7ce51348"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74509.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74509"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"cba6b758711cab946c787f7c15be92cc749b8e1f"},{"fixed":"565971488191bf54a87a417abafab6ad0de72201"},{"fixed":"c4cec575a6d6f7c36808a3a0017b0675968bb06b"},{"fixed":"95cdcd8c82a501931fd3ae9b3811b0b6da167e94"},{"fixed":"eb1d8318764de7216e6dbba29a24d69f7ce51348"},{"fixed":"b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3"},{"fixed":"cdc36db204ffd97b947d64374cf23a210dc74777"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.15.210"},{"fixed":"5.16"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"42fe380baaaccbe635c34ca07b29d19b9ec2498d"}]}],"versions":["v5.15.223","v5.15.222","v5.15.221","v5.15.220","v5.15.219","v5.15.218","v5.15.217","v5.15.216","v5.15.215","v5.15.214","v5.15.213","v5.15.212","v5.15.211","v5.15.210"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74509.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.17.0"},{"fixed":"6.1.184"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.154"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.103"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.44"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74509.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}