CVE-2026-64473

What the bug is

VFIO device debugfs files created with debugfs_create_devm_seqfile() store a devres allocated debugfs_devm_entry as inode private data. vfio_unregister_group_dev() currently calls vfio_device_del() before vfio_device_debugfs_exit(), but device_del() releases devres. This can leave debugfs entries visible with stale inode private data while unregister waits for userspace references to drain. Remove the per-device debugfs tree before vfio_device_del(). The debugfs view is diagnostic only, so losing it at the start of unregister is preferable to preserving entries whose backing storage may already have been released. Complete the teardown by clearing the per-device debugfs root after removal. This matches the global debugfs root cleanup and prevents future users from mistaking a removed dentry for a live debugfs tree during the remainder of unregister.

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/vfio/debugfs.c
drivers/vfio/vfio_main.c

What this is

VFIO DRIVERMAINTAINERS section matched on drivers/vfio/ · kvm@vger.kernel.org · Maintained

Kernel module

vfio

Check it on the machine

grep -wE 'CONFIG_VFIO|CONFIG_VFIO_DEBUGFS' /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 vfio

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 does not build this code in 4 releases. It does build it in 1 release, so the answer depends on which release the machine runs.

• bookwormMnot built on armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp
• trixie, forky, sid, bookworm · linux-6.12n

M

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

n

not enabled on any flavour - this release does not build the code

Build switches

CONFIG_VFIO, CONFIG_VFIO_DEBUGFS

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

2026-07-25 (3 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 6.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/vfio

Upstream fixes

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

Introduced	Fixed in	Commit
6.8	6.12.96	6cc60b41d616
6.8	6.18.39	a53109ffb6b5
6.8	7.1.4	a5df401dc84f
6.8	7.2	dc7fe87de492

Debian advisories