Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 Bluetooth HCI Core net/bluetooth/hci_core.c hci_register_dev race condition

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.5	$0-$5k	0.29+

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 and classified as very critical. Affected by this vulnerability is the function hci_register_dev of the file net/bluetooth/hci_core.c of the component Bluetooth HCI Core. The manipulation leads to race condition. This vulnerability is uniquely identified as CVE-2026-98109. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 and classified as very critical. This issue affects the function hci_register_dev of the file net/bluetooth/hci_core.c of the component Bluetooth HCI Core. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Fix race condition during device registration In hci_register_dev(), the power_on work item is queued to hdev->req_workqueue before initializing hdev->adv_monitors_idr and registering the MSFT extension via msft_register(). For devices marked with quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on the device. When the power_on work item runs concurrently on another CPU, hci_power_on() detects that the device is unconfigured and immediately invokes hci_dev_do_close(), which calls msft_do_close(). Concurrently, msft_register() allocates the msft structure and exposes it to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If msft_do_close() executes while hdev->msft_data is already assigned but the mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates on an uninitialized mutex, triggering a DEBUG_LOCKS warning: DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline] WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821 ... Call Trace: <TASK> msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693 hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0x92d/0xe10 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Fix this by moving the queue_work() call in hci_register_dev() to after idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device structures and extensions are fully initialized before asynchronous tasks can access them. Additionally, assign hdev->msft_data in msft_register() only after mutex_init(&msft->filter_lock) has completed.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-98109 since 09/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc2 eliminates this vulnerability. Applying the patch b1faf348c29e6f8302ec7769cbf1c1ef05be014f/a11ebe8dc0333fb870bbbb656b34690e87ee3f98/d427b1c71d9798083e954d3c13469dc0a2305868/57938bbdb9bf7fd41cbd5cd509ec10c4b22bec18 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.110
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 6.18.51
• 6.18.52
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.111/6.18.53/7.2.7/7.3-rc2
Patch: b1faf348c29e6f8302ec7769cbf1c1ef05be014f/a11ebe8dc0333fb870bbbb656b34690e87ee3f98/d427b1c71d9798083e954d3c13469dc0a2305868/57938bbdb9bf7fd41cbd5cd509ec10c4b22bec18

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98109 (🔒)
GCVE (CVE): GCVE-0-2026-98109
GCVE (VulDB): GCVE-100-409937

Entryinfo

Created: 09/25/2026 13:02
Changes: 09/25/2026 13:02 (60)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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