CVE-2026-68087: HID: wacom: use GFP_ATOMIC in wacom_wac_queue_flush()

CVE-2026-68087: HID: wacom: use GFP_ATOMIC in wacom_wac_queue_flush()

[Greg Kroah-Hartman]

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

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

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

HID: wacom: use GFP_ATOMIC in wacom_wac_queue_flush()

wacom_wac_queue_flush() is called via the .raw_event callback
(wacom_raw_event → wacom_wac_pen_serial_enforce → wacom_wac_queue_flush).
For USB HID devices, this callback is invoked from hid_irq_in(), which
is a URB completion handler running in atomic context. Using GFP_KERNEL
in this path can sleep, leading to a "scheduling while atomic" bug.

Use GFP_ATOMIC instead. The existing code already handles allocation
failure by skipping the fifo entry and continuing.

The Linux kernel CVE team has assigned CVE-2026-68087 to this issue.


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

	Issue introduced in 6.15 with commit 5e013ad206895e72d7da41bc1ae89d8cb499c3aa and fixed in 6.18.39 with commit bbe1e55629bfaabd4b2e8125b48dd3503d74ac8b
	Issue introduced in 6.15 with commit 5e013ad206895e72d7da41bc1ae89d8cb499c3aa and fixed in 7.1.4 with commit 27c4dad1b7917b747bf080792a527997e3147c69
	Issue introduced in 6.15 with commit 5e013ad206895e72d7da41bc1ae89d8cb499c3aa and fixed in 7.2-rc1 with commit 55f1ad573e34abf9a0443c34bc5a63d74edba7d7

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-2026-68087
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/hid/wacom_sys.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/bbe1e55629bfaabd4b2e8125b48dd3503d74ac8b
	https://git.kernel.org/stable/c/27c4dad1b7917b747bf080792a527997e3147c69
	https://git.kernel.org/stable/c/55f1ad573e34abf9a0443c34bc5a63d74edba7d7