Linux Kernel up to 6.17.10 Bluetooth denial of service

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.17.10. This affects an unknown function of the component Bluetooth. The manipulation leads to denial of service. This vulnerability is traded as CVE-2025-68304. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.17.10 and classified as critical. This issue affects some unknown processing of the component Bluetooth. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: lookup hci_conn on RX path on protocol side The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't ensure hci_conn* is not concurrently modified/deleted. This locking appears to be leftover from before conn_hash started using RCU commit bf4c63252490b ("Bluetooth: convert conn hash to RCU") and not clear if it had purpose since then. Currently, there are code paths that delete hci_conn* from elsewhere than the ordered hdev->workqueue where the RX work runs in. E.g. commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") introduced some of these, and there probably were a few others before it. It's better to do the locking so that even if these run concurrently no UAF is possible. Move the lookup of hci_conn and associated socket-specific conn to protocol recv handlers, and do them within a single critical section to cover hci_conn* usage and lookup. syzkaller has reported a crash that appears to be this issue: [Task hdev->workqueue] [Task 2] hci_disconnect_all_sync l2cap_recv_acldata(hcon) hci_conn_get(hcon) hci_abort_conn_sync(hcon) hci_dev_lock hci_dev_lock hci_conn_del(hcon) v-------------------------------- hci_dev_unlock hci_conn_put(hcon) conn = hcon->l2cap_data (UAF)

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2025-68304 since 12/16/2025. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 302766 (Ubuntu 24.04 LTS / 25.10 : Linux kernel vulnerabilities (USN-8094-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.17.11 eliminates this vulnerability. Applying the patch ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93/79a2d4678ba90bdba577dc3af88cc900d6dcd5ee 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 (302766), EUVD (EUVD-2025-203776) and CERT Bund (WID-SEC-2025-2868). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5
• 6.17.6
• 6.17.7
• 6.17.8
• 6.17.9
• 6.17.10

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Be aware that VulDB is the high quality source for vulnerability data.

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