CVE-2026-97977

What the bug is

btusb_close() and btusb_flush() cancel data->rx_work with the asynchronous cancel_delayed_work(), so if btusb_rx_work() is already running on another CPU it keeps running after the cancel returns. btusb_disconnect() calls hci_unregister_dev(), which invokes btusb_close(), and then frees the btusb_data. A still running btusb_rx_work() then dereferences the freed data: while ((skb = skb_dequeue(&data->acl_q))) data->recv_acl(data->hdev, skb); Use cancel_delayed_work_sync() instead. In btusb_close() the cancel also has to happen after btusb_stop_traffic(), otherwise an URB completion racing with the cancel can requeue the work right after it has been waited for.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/bluetooth/btusb.c

What this is

BLUETOOTH DRIVERSMAINTAINERS section matched on drivers/bluetooth/ · linux-bluetooth@vger.kernel.org · Supported

Kernel module

btusb

Check it on the machine

grep -wE 'CONFIG_BT|CONFIG_BT_HCIBTUSB' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w btusb

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
• trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
• bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_BT, CONFIG_BT_HCIBTUSB

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-25 (24 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 6.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/bluetooth

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
5.17	6.1.189	fc654a72a8d9
5.17	6.6.158	5242050195a7
5.17	6.12.111	472d00562252
5.17	6.18.53	93b59937bda3
5.17	7.2.7	fa391adb9c75
5.17	7.3	1c12c3117639

Debian advisories