{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74509", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.909Z", "datePublished": "2026-08-15T12:27:31.896Z", "dateUpdated": "2026-08-27T12:39:46.394Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-27T12:39:46.394Z" }, "descriptions": [ { "lang": "en", "value": "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 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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - The bug is in the Bluetooth HCI LE extended-advertising path; a remote/adjacent peer can deliver the LE Extended Advertising Set Terminated HCI event that frees adv_info while hci_cmd_sync_work waits on the controller during scan-response/advertising-data updates on phones and other BLE devices.\nAC:L - This is a use-after-free race between hci_cmd_sync_work and hci_rx_work where the attacker controls the terminating side by repeatedly initiating BLE connections/terminations during the up-to-2s HCI command wait, and can also drive the setup side via MGMT advertising commands.\nPR:N - An adjacent Bluetooth attacker needs no account, credentials, or capabilities on the victim; exploitation only requires the victim stack to be configuring BLE advertising (normal on Android phones, laptops, and IoT) while the attacker sends over-the-air BLE traffic to trigger hci_le_ext_adv_term_evt.\nUI:N - No deliberate victim action is required beyond a device running Bluetooth with LE advertising updates (common default behavior); the attacker triggers the race remotely without social engineering, file opens, or mounts.\nS:U - Impact is kernel heap corruption and potential local privilege escalation within the same kernel security domain; it does not cross a VM, container, or IOMMU boundary.\nC:H - Multiple UAF paths read freed adv_info (e.g., eir_create_scan_rsp/adv_data) and retain dangling pointers across __hci_cmd_sync_status waits, enabling slab reuse and arbitrary kernel memory disclosure via heap grooming.\nI:H - KASAN shows a post-free write to adv_info (scan_rsp_changed); similar paths write adv_data_changed and tx_power on freed objects, providing exploitable heap corruption for arbitrary kernel writes and code execution.\nA:H - Use-after-free on adv_info in hci_cmd_sync_work can cause immediate kernel oops/panic or hung BLE subsystem during advertising reconfiguration, and is reachable from unauthenticated adjacent BLE interaction on actively advertising devices." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/hci_sync.c" ], "versions": [ { "version": "cba6b758711cab946c787f7c15be92cc749b8e1f", "lessThan": "565971488191bf54a87a417abafab6ad0de72201", "status": "affected", "versionType": "git" }, { "version": "cba6b758711cab946c787f7c15be92cc749b8e1f", "lessThan": "c4cec575a6d6f7c36808a3a0017b0675968bb06b", "status": "affected", "versionType": "git" }, { "version": "cba6b758711cab946c787f7c15be92cc749b8e1f", "lessThan": "95cdcd8c82a501931fd3ae9b3811b0b6da167e94", "status": "affected", "versionType": "git" }, { "version": "cba6b758711cab946c787f7c15be92cc749b8e1f", "lessThan": "eb1d8318764de7216e6dbba29a24d69f7ce51348", "status": "affected", "versionType": "git" }, { "version": "cba6b758711cab946c787f7c15be92cc749b8e1f", "lessThan": "b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3", "status": "affected", "versionType": "git" }, { "version": "cba6b758711cab946c787f7c15be92cc749b8e1f", "lessThan": "cdc36db204ffd97b947d64374cf23a210dc74777", "status": "affected", "versionType": "git" }, { "version": "42fe380baaaccbe635c34ca07b29d19b9ec2498d", "status": "affected", "versionType": "git" }, { "version": "5.15.210", "lessThan": "5.16", "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_sync.c" ], "versions": [ { "version": "5.17", "status": "affected" }, { "version": "0", "lessThan": "5.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.154", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "5.17", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.6.154" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.210" } ] } ] } ], "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" } ], "title": "Bluetooth: hci_sync: Fix advertising data UAFs", "x_generator": { "engine": "bippy-1.2.0" } } } }