[PATCH 2/2] Input: rmi4 - fix num_subpackets overflow in register descriptor

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

RMI_REG_DESC_SUBPACKET_BITS is defined as 296 (37 * BITS_PER_BYTE). This
may overflow num_subpackets in struct rmi_register_desc_item which is
defined as a u8.

Fix this by changing the type of num_subpackets to u16.

Pack the structure by rearranging the members to avoid holes, change
reg_size from unsigned long to u32 to save space and ensure consistent
size across 32-bit and 64-bit architectures, and use DECLARE_BITMAP()
for subpacket_map.

Fixes: 2b6a321da9a2 ("Input: synaptics-rmi4 - add support for Synaptics RMI4 devices")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/rmi4/rmi_driver.h | 8 ++++----
 drivers/input/rmi4/rmi_f12.c    | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/input/rmi4/rmi_driver.h b/drivers/input/rmi4/rmi_driver.h
index e84495caab15..865ffc7882f3 100644
--- a/drivers/input/rmi4/rmi_driver.h
+++ b/drivers/input/rmi4/rmi_driver.h
@@ -11,6 +11,7 @@
 #include <linux/hrtimer.h>
 #include <linux/ktime.h>
 #include <linux/input.h>
+#include <linux/types.h>
 #include "rmi_bus.h"
 
 #define SYNAPTICS_INPUT_DEVICE_NAME "Synaptics RMI4 Touch Sensor"
@@ -52,10 +53,9 @@ struct pdt_entry {
 /* describes a single packet register */
 struct rmi_register_desc_item {
 	u16 reg;
-	unsigned long reg_size;
-	u8 num_subpackets;
-	unsigned long subpacket_map[BITS_TO_LONGS(
-				RMI_REG_DESC_SUBPACKET_BITS)];
+	u16 num_subpackets;
+	u32 reg_size;
+	DECLARE_BITMAP(subpacket_map, RMI_REG_DESC_SUBPACKET_BITS);
 };
 
 /*
diff --git a/drivers/input/rmi4/rmi_f12.c b/drivers/input/rmi4/rmi_f12.c
index 8246fe77114b..9bcc27e9d308 100644
--- a/drivers/input/rmi4/rmi_f12.c
+++ b/drivers/input/rmi4/rmi_f12.c
@@ -88,7 +88,7 @@ static int rmi_f12_read_sensor_tuning(struct f12_data *f12)
 
 	if (item->reg_size > sizeof(buf)) {
 		dev_err(&fn->dev,
-			"F12 control8 should be no bigger than %zd bytes, not: %ld\n",
+			"F12 control8 should be no bigger than %zd bytes, not: %d\n",
 			sizeof(buf), item->reg_size);
 		return -ENODEV;
 	}
-- 
2.54.0.545.g6539524ca2-goog