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CVE-2026-64601
ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on each resubmission
Published 2026-08-06 (2 months ago) by the Linux kernel CNA. Subsystem sound/usb. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-64601 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.1.4-1 | Update the kernel and reboot. Fixed in 7.1.4-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.4-1 | Update the kernel and reboot. Fixed in 7.1.4-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
In capture_urb_complete(), usb_anchor_urb() is called on every completion callback, but the URB is already anchored from the initial submission in tascam_trigger_start(). Each redundant call corrupts the anchor's doubly-linked list and inflates the URB refcount. When usb_kill_anchored_urbs() traverses the list during stream stop / suspend / disconnect, the corrupted list leads to use-after-free. Remove the redundant usb_anchor_urb() from the resubmit path.
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.
sound/usb/usx2y/us144mkii_capture.c
- What this is
- SOUNDMAINTAINERS section matched on sound/ · linux-sound@vger.kernel.org · Maintained
Check it on the machine
grep -wE 'CONFIG_SND|CONFIG_SND_USB_US144MKII' /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.
Show whether Debian builds this, per release
Debian does not build this code in 2 releases. The build rule could not be established for 2 releases, so nothing is claimed about those.
- bookworm, trixie?
- forky, sidn
- ?
- not established - no Makefile entry for the affected file
- n
- not enabled on any flavour - this release does not build the code
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.
- Build switches
- CONFIG_SND, CONFIG_SND_USB_US144MKII
- 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
- 2026-08-06 (2 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.17%, higher than 5.8% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- sound/usb
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.18 | 6.18.39 | 16f14f55141d |
| 6.18 | 7.1.4 | ab1db6491242 |
| 6.18 | 7.2 | 5cff1529a2f9 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The bug is reached through local ALSA PCM open/ioctl paths on /dev/snd/pcmC*D* (START/STOP via tascam_pcm_trigger), not via network protocols; a present TASCAM US-144/US-144MKII is a deployment prerequisite, and Local is chosen over Physical under the uncertainty rule.
- AC:LAttack complexity, low
- An attacker who can open the PCM device can deterministically start capture (submitting URBs that complete and hit capture_urb_complete), then stop/suspend to invoke usb_kill_anchored_urbs on the corrupted anchor; no conditions outside attacker control are required.
- PR:LPrivileges required, low
- The PCM path has no capability checks; ordinary local access to ALSA device nodes (audio group or seat/udev ACLs on studio/desktop systems with this interface) is sufficient, not init-namespace root.
- UI:NUser interaction, none
- The attacker alone opens the PCM device, starts and stops the stream, and thereby triggers URB resubmission corruption and the subsequent kill/UAF path without any separate victim action.
- S:UScope, unchanged
- The use-after-free corrupts kernel USB/ALSA state within the same host kernel security authority and does not cross a VM, IOMMU, or other separate boundary.
- C:HConfidentiality impact, high
- Corrupted usb_anchor list traversal during usb_kill_anchored_urbs yields a kernel use-after-free; per guidance UAF enables reclaim of freed objects and arbitrary kernel information disclosure.
- I:HIntegrity impact, high
- The same UAF on URB/anchor-linked objects can be turned into heap reuse and control-flow hijacking primitives, so integrity impact is High rather than a mere crash.
- A:HAvailability impact, high
- Traversing the corrupted anchor list or under-referenced URB state during stream stop, suspend, or disconnect can oops/panic the kernel, giving High availability impact.