CVE-2026-64341: USB: iowarrior: fix use-after-free on disconnect race

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

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

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

USB: iowarrior: fix use-after-free on disconnect race

mutex_unlock() may access the mutex structure after releasing the lock
and therefore cannot be used to manage lifetime of objects directly
(unlike spinlocks and refcounts). [1][2]

Use a kref to release the driver data to avoid use-after-free in
mutex_unlock() when release() races with disconnect().

[1] a51749ab34d9 ("locking/mutex: Document that mutex_unlock() is non-atomic")
[2] 2b9d9e0a9ba0 ("locking/mutex: Clarify that mutex_unlock(), and most
                   other sleeping locks, can still use the lock object
                   after it's unlocked")

The Linux kernel CVE team has assigned CVE-2026-64341 to this issue.


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

	Issue introduced in 2.6.21 with commit 946b960d13c15f050a3b848987aaca79f6a459b7 and fixed in 6.12.97 with commit 3c0a7b29ebb391d5f50b115e86f842b709195b08
	Issue introduced in 2.6.21 with commit 946b960d13c15f050a3b848987aaca79f6a459b7 and fixed in 7.1.4 with commit 71590982700fdeb39a37a500c877228b0140978e
	Issue introduced in 2.6.21 with commit 946b960d13c15f050a3b848987aaca79f6a459b7 and fixed in 7.2-rc3 with commit c602254ba4c10f60a73cd99d147874f86a3f485c

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-2026-64341
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:
	drivers/usb/misc/iowarrior.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/3c0a7b29ebb391d5f50b115e86f842b709195b08
	https://git.kernel.org/stable/c/71590982700fdeb39a37a500c877228b0140978e
	https://git.kernel.org/stable/c/c602254ba4c10f60a73cd99d147874f86a3f485c