CVE-2026-64601: ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on each resubmission

From: Greg Kroah-Hartman <[email protected]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on each resubmission

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.

The Linux kernel CVE team has assigned CVE-2026-64601 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.18 with commit c1bb0c13e430623c26543baae5bb9ae21139db87 and fixed in 6.18.39 with commit 16f14f55141d4c55c3f321f93c328fff7cd6860a
	Issue introduced in 6.18 with commit c1bb0c13e430623c26543baae5bb9ae21139db87 and fixed in 7.1.4 with commit ab1db64912428cdf06a4f9542e16e0575e9ad59f
	Issue introduced in 6.18 with commit c1bb0c13e430623c26543baae5bb9ae21139db87 and fixed in 7.2-rc2 with commit 5cff1529a2f9b3461a7f5a6e36a86682fc290534

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64601
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	sound/usb/usx2y/us144mkii_capture.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/16f14f55141d4c55c3f321f93c328fff7cd6860a
	https://git.kernel.org/stable/c/ab1db64912428cdf06a4f9542e16e0575e9ad59f
	https://git.kernel.org/stable/c/5cff1529a2f9b3461a7f5a6e36a86682fc290534