CVE-2026-64472

What the bug is

Bitfield operations are not atomic, they use a read-modify-write pattern, therefore we should be careful not to pack bitfields that can be concurrently updated into the same storage unit. This split takes a binary approach: flags that are only modified pre/post open/close remain bitfields, flags modified from user action, including actions that reach across to another device (ex. reset) use dedicated storage units. Note mlx5_vhca_page_tracker.status is relocated to fill the alignment hole this split exposes. Bitfield justifications: migrate_cap: written only in mlx5vf_cmd_set_migratable() at probe chunk_mode: written only in mlx5vf_cmd_set_migratable() at probe mig_state_cap: written only in mlx5vf_cmd_set_migratable() at probe Dedicated storage units: mdev_detach: written in the VF attach/detach event notifier mlx5fv_vf_event() at runtime log_active: written in mlx5vf_start_page_tracker()/ mlx5vf_stop_page_tracker() during runtime dirty tracking deferred_reset: written in mlx5vf_state_mutex_unlock()/ mlx5vf_pci_aer_reset_done() during runtime reset handling is_err: set by tracker error handling and dirty-log polling at runtime object_changed: set by tracker event handling and cleared by dirty-log polling at runtime

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/pci/mlx5/cmd.h

What this is

VFIO MLX5 PCI DRIVERMAINTAINERS section matched on drivers/vfio/pci/mlx5/ · kvm@vger.kernel.org · Maintained

Show whether Debian builds this, per release

Not established. This site could not find the build rule for the affected file in the kernel trees Debian ships, so it has no answer about whether Debian compiles this code. Read that as unknown, never as absent.

• bookworm, trixie, forky, sid, bookworm · linux-6.12?

?

not established - no Makefile entry for the affected file

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

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

Signals

Published

2026-07-25 (3 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 7.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

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
5.19	6.1.178	1dd99b8f4e14
5.19	6.6.145	f1db80a67da9
5.19	6.12.97	399d806f998f
5.19	6.18.40	7ed120b1a007
5.19	7.1.4	39d163627b51
5.19	7.2	f2365a63b02d

Debian advisories