Linux Kernel up to 6.1.158/6.6.116/6.12.57/6.17.7 Bluetooth hci_cmd_sync_dequeue_once use after free

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.1.158/6.6.116/6.12.57/6.17.7. The impacted element is the function hci_cmd_sync_dequeue_once of the component Bluetooth. Such manipulation leads to use after free. This vulnerability is listed as CVE-2025-40318. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.158/6.6.116/6.12.57/6.17.7. Affected by this issue is the function hci_cmd_sync_dequeue_once of the component Bluetooth. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once hci_cmd_sync_dequeue_once() does lookup and then cancel the entry under two separate lock sections. Meanwhile, hci_cmd_sync_work() can also delete the same entry, leading to double list_del() and "UAF". Fix this by holding cmd_sync_work_lock across both lookup and cancel, so that the entry cannot be removed concurrently.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-40318 since 04/16/2025. The exploitation is known to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 296620 (RHEL 9 : kernel (RHSA-2026:1194)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.159, 6.6.117, 6.12.58 or 6.17.8 eliminates this vulnerability. Applying the patch 0a94f7e017438935c09ef833a1aa908ad9875213/932c0a4f77ac13e526fdd5b42914d29c9821d389/ae76cf6c2c842944c6514c57df54d728f1916553/9cd536970192b72257afcdfba0bfc09993e6f19c/09b0cd1297b4dbfe736aeaa0ceeab2265f47f772 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (296620) and CERT Bund (WID-SEC-2025-2756). Once again VulDB remains the best source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• NetApp FAS
• NetApp AFF
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel
• Microsoft Azure Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.158
• 6.6.116
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5
• 6.17.6
• 6.17.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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