From: Jinmo Yang <jinmo44.yang@gmail.com>
Date: Mon, 1 Jun 2026 13:41:23 +0000 (+0900)
Subject: HID: wacom: use GFP_ATOMIC in wacom_wac_queue_flush()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=55f1ad573e34abf9a0443c34bc5a63d74edba7d7;p=thirdparty%2Fkernel%2Flinux.git

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.

Reported-by: Sashiko-bot <sashiko-bot@kernel.org>
Fixes: 5e013ad20689 ("HID: wacom: Remove static WACOM_PKGLEN_MAX limit")
Cc: stable@vger.kernel.org
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jinmo Yang <jinmo44.yang@gmail.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index fac75c2024539..3a06be1e163ae 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -76,7 +76,7 @@ static void wacom_wac_queue_flush(struct hid_device *hdev,
 		unsigned int count;
 		int err;
 
-		buf = kzalloc(size, GFP_KERNEL);
+		buf = kzalloc(size, GFP_ATOMIC);
 		if (!buf) {
 			kfifo_skip(fifo);
 			continue;