From 749ab300d41bcdbb8edf776d20e9a9891e79eba4 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Sat, 14 Apr 2018 17:06:45 +0200
Subject: [PATCH] HID: intel_ish-hid: Stop using a static local buffer in get_report()
Git-commit: 749ab300d41bcdbb8edf776d20e9a9891e79eba4
Patch-mainline: v4.17-rc5
References: jsc#SLE-5241

hid_ishtp_get_report() may be called by multiple callers at the same
time, causing trouble with the static local buffer used.

Also there is no reason to use a non stack buffer, the buffer is tiny
and ishtp_cl_send() copies its contents so the lifetime is not an
issue either.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/hid/intel-ish-hid/ishtp-hid-client.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/intel-ish-hid/ishtp-hid-client.c b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
index 6ce1856bb368..acc2536c8094 100644
--- a/drivers/hid/intel-ish-hid/ishtp-hid-client.c
+++ b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
@@ -412,9 +412,7 @@ void hid_ishtp_get_report(struct hid_device *hid, int report_id,
 {
 	struct ishtp_hid_data *hid_data =  hid->driver_data;
 	struct ishtp_cl_data *client_data = hid_data->client_data;
-	static unsigned char	buf[10];
-	unsigned int	len;
-	struct hostif_msg_to_sensor *msg = (struct hostif_msg_to_sensor *)buf;
+	struct hostif_msg_to_sensor msg = {};
 	int	rv;
 	int	i;
 
@@ -426,14 +424,11 @@ void hid_ishtp_get_report(struct hid_device *hid, int report_id,
 		return;
 	}
 
-	len = sizeof(struct hostif_msg_to_sensor);
-
-	memset(msg, 0, sizeof(struct hostif_msg_to_sensor));
-	msg->hdr.command = (report_type == HID_FEATURE_REPORT) ?
+	msg.hdr.command = (report_type == HID_FEATURE_REPORT) ?
 		HOSTIF_GET_FEATURE_REPORT : HOSTIF_GET_INPUT_REPORT;
 	for (i = 0; i < client_data->num_hid_devices; ++i) {
 		if (hid == client_data->hid_sensor_hubs[i]) {
-			msg->hdr.device_id =
+			msg.hdr.device_id =
 				client_data->hid_devices[i].dev_id;
 			break;
 		}
@@ -442,8 +437,9 @@ void hid_ishtp_get_report(struct hid_device *hid, int report_id,
 	if (i == client_data->num_hid_devices)
 		return;
 
-	msg->report_id = report_id;
-	rv = ishtp_cl_send(client_data->hid_ishtp_cl, buf, len);
+	msg.report_id = report_id;
+	rv = ishtp_cl_send(client_data->hid_ishtp_cl, (uint8_t *)&msg,
+			    sizeof(msg));
 	if (rv)
 		hid_ishtp_trace(client_data,  "%s hid %p send failed\n",
 				__func__, hid);
-- 
2.16.4