FKIE_CVE-2026-74509
Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-27 13:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Fix advertising data UAFs
hci_find_adv_instance() returns an adv_info pointer that is valid only
while hdev->lock is held. The advertising command-sync paths perform
instance lookups without that lock and, in some cases, retain the pointer
while waiting for a controller response.
An advertising termination event can therefore interleave as follows:
hci_cmd_sync_work hci_rx_work
hci_find_adv_instance()
__hci_cmd_sync_status()
wait for controller reply hci_dev_lock()
hci_remove_adv_instance()
kfree(adv)
adv->scan_rsp_changed = false
KASAN reported:
BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
hci_schedule_adv_instance_sync+0x390/0x4c0
hci_cmd_sync_work+0x173/0x300
Allocated by task 87:
hci_add_adv_instance+0x538/0xac0
add_advertising+0x885/0x1160
Freed by task 89:
kfree+0x131/0x3c0
hci_remove_adv_instance+0x1d8/0x3b0
hci_le_ext_adv_term_evt+0x17b/0x730
Protect the instance lookup and payload construction in the extended
advertising, scan response, and periodic advertising data paths. Snapshot
the advertising parameters under hdev->lock, but release the lock before
waiting for the controller.
Clear advertising-data dirty bits before issuing their commands and
restore them after a failure using a fresh lookup. Likewise, update the
reported transmit power through a fresh lookup after the parameter command
completes. No adv_info pointer then survives an HCI command wait.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bluetooth/hci_sync.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "565971488191bf54a87a417abafab6ad0de72201",
"status": "affected",
"version": "cba6b758711cab946c787f7c15be92cc749b8e1f",
"versionType": "git"
},
{
"lessThan": "c4cec575a6d6f7c36808a3a0017b0675968bb06b",
"status": "affected",
"version": "cba6b758711cab946c787f7c15be92cc749b8e1f",
"versionType": "git"
},
{
"lessThan": "95cdcd8c82a501931fd3ae9b3811b0b6da167e94",
"status": "affected",
"version": "cba6b758711cab946c787f7c15be92cc749b8e1f",
"versionType": "git"
},
{
"lessThan": "eb1d8318764de7216e6dbba29a24d69f7ce51348",
"status": "affected",
"version": "cba6b758711cab946c787f7c15be92cc749b8e1f",
"versionType": "git"
},
{
"lessThan": "b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3",
"status": "affected",
"version": "cba6b758711cab946c787f7c15be92cc749b8e1f",
"versionType": "git"
},
{
"lessThan": "cdc36db204ffd97b947d64374cf23a210dc74777",
"status": "affected",
"version": "cba6b758711cab946c787f7c15be92cc749b8e1f",
"versionType": "git"
},
{
"status": "affected",
"version": "42fe380baaaccbe635c34ca07b29d19b9ec2498d",
"versionType": "git"
},
{
"lessThan": "5.16",
"status": "affected",
"version": "5.15.210",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/bluetooth/hci_sync.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.17"
},
{
"lessThan": "5.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.184",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.154",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"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-\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."
}
],
"id": "CVE-2026-74509",
"lastModified": "2026-08-27T13:18:34.330",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "ADJACENT_NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-15T13:17:55.950",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/565971488191bf54a87a417abafab6ad0de72201"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/95cdcd8c82a501931fd3ae9b3811b0b6da167e94"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c4cec575a6d6f7c36808a3a0017b0675968bb06b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/cdc36db204ffd97b947d64374cf23a210dc74777"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/eb1d8318764de7216e6dbba29a24d69f7ce51348"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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