CVE-2025-21827: linux kernel — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface() The documentation for usb_driver_claim_interface() says that "the device lock" is needed when the function is called from places other than probe(). This appears to be the lock for the USB interface device. The Mediatek btusb code gets called via this path: Workqueue: hci0 hci_power_on [bluetooth] Call trace: usb_driver_claim_interface btusb_mtk_claim_iso_intf btusb_mtk_setup hci_dev_open_sync hci_power_on process_scheduled_works worker_thread kthread With the above call trace the device lock hasn't been claimed. Claim it. Without this fix, we'd sometimes see the error "Failed to claim iso interface". Sometimes we'd even see worse errors, like a NULL pointer dereference (where `intf->dev.driver` was NULL) with a trace like: Call trace: usb_suspend_both usb_runtime_suspend __rpm_callback rpm_suspend pm_runtime_work process_scheduled_works Both errors appear to be fixed with the proper locking.

Is your site exposed to CVE-2025-21827?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-667 CWE-667

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.11 — 6.12.13
linux	linux_kernel	6.13 — 6.13.2

References

Advisories & Patches

https://git.kernel.org/stable/c/4194766ec8756f4f654d595ae49962acbac49490 https://git.kernel.org/stable/c/930e1790b99e5839e1af69d2f7fd808f1fba2df9 https://git.kernel.org/stable/c/e9087e828827e5a5c85e124ce77503f2b81c3491

Frequently Asked Questions

What is CVE-2025-21827? +

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface() The documentation for usb_driver_claim_interface() says that "the device lock" is needed when the function is called from places other than probe(). This appears to be the lock for the USB interface device. The Mediatek btusb code gets called via this path: Workqueue: hci0 hci_power_on [bluetooth] Call trace: usb_driver_claim_interface btusb_mtk_claim_iso_intf btusb_mtk_setup hci_dev_open_sync hci_power_on process_scheduled_works worker_thread kthread With the above call trace the device lock hasn't been claimed. Claim it. Without this fix, we'd sometimes see the error "Failed to claim iso interface". Sometimes we'd even see worse errors, like a NULL pointer dereference (where `intf->dev.driver` was NULL) with a trace like: Call trace: usb_suspend_both usb_runtime_suspend __rpm_callback rpm_suspend pm_runtime_work process_scheduled_works Both errors appear to be fixed with the proper locking. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-21827? +

CVE-2025-21827 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-21827? +

CVE-2025-21827 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21827? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-1221

A Zigbee Radio Co-Processor (RCP), which is using SiLabs EmberZNet Zigbee stack, was unable to send messages to the host …

CVE-2025-10151

Improper locking vulnerability in Softing Industrial Automation GmbH gateways allows infected memory and/or resource leak exposure.This issue affects smartLink HW-PN: …

CVE-2026-54906 9.8

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLock#release_write_lock does not verify that the calling thread acquired …

CVE-2026-43215 8.8

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix locking usage for tcon fields We used to …

CVE-2026-62426 8.8

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] To manage the …

CVE-2026-31629 8.8

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: add missing return after LLCP_CLOSED checks In nfc_llcp_recv_hdlc() …

CVE-2025-21827