linux-cve-announce - CVE-2025-71073: Input: lkkbd - disable pending work before freeing device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2026011325-CVE-2025-71073-b002@gregkh>
Date: Tue, 13 Jan 2026 16:31:31 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-71073: Input: lkkbd - disable pending work before freeing device

From: Greg Kroah-Hartman <gregkh@...nel.org>

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

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

Input: lkkbd - disable pending work before freeing device

lkkbd_interrupt() schedules lk->tq via schedule_work(), and the work
handler lkkbd_reinit() dereferences the lkkbd structure and its
serio/input_dev fields.

lkkbd_disconnect() and error paths in lkkbd_connect() free the lkkbd
structure without preventing the reinit work from being queued again
until serio_close() returns. This can allow the work handler to run
after the structure has been freed, leading to a potential use-after-free.

Use disable_work_sync() instead of cancel_work_sync() to ensure the
reinit work cannot be re-queued, and call it both in lkkbd_disconnect()
and in lkkbd_connect() error paths after serio_open().

The Linux kernel CVE team has assigned CVE-2025-71073 to this issue.

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

	Fixed in 6.12.64 with commit 3a7cd1397c209076c371d53bf39a55c138f62342
	Fixed in 6.18.3 with commit cffc4e29b1e2d44ab094cf142d7c461ff09b9104
	Fixed in 6.19-rc2 with commit e58c88f0cb2d8ed89de78f6f17409d29cfab6c5c

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-2025-71073
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/input/keyboard/lkkbd.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/3a7cd1397c209076c371d53bf39a55c138f62342
	https://git.kernel.org/stable/c/cffc4e29b1e2d44ab094cf142d7c461ff09b9104
	https://git.kernel.org/stable/c/e58c88f0cb2d8ed89de78f6f17409d29cfab6c5c