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Fencer Vulns
high 7.8

CVE-2025-21827 json

Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface()

published 2025-03-06 20 mo ago modified 2026-10-15 24 d ago also EUVD-2025-6218

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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.

Patch / fix

  • Linux Linux 6.12.13, 6.13.2, 6.14
  • linux Debian 14, Debian 13 6.12.13-1

debian advisories DEBIAN-CVE-2025-21827

  • linux-gcp-6.11 Ubuntu 24.04 LTS 6.11.0-1015.15~24.04.1
  • linux-hwe-6.11 Ubuntu 24.04 LTS 6.11.0-26.26~24.04.1
  • linux-oem-6.11 Ubuntu 24.04 LTS 6.11.0-1022.22
  • linux-azure-6.11 Ubuntu 24.04 LTS 6.11.0-1015.15~24.04.1
  • linux-nvidia-6.11 Ubuntu 24.04 LTS 6.11.0-1010.10
  • linux-lowlatency-hwe-6.11 Ubuntu 24.04 LTS 6.11.0-1014.15~24.04.1

ubuntu advisories UBUNTU-CVE-2025-21827

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-21827 updated cvss 5.5

kernel: Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.