[PATCH 7.0 006/201] HID: pidff: Fix integer overflow in pidff_rescale

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

7.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com>

commit 48d1677779ad6816978ad4a4f7588aec5ec960fe upstream.

Rescaling values close to the max (U16_MAX) temporarily creates values
that exceed the s32 range. This caused value overflow in case when, for
example, a periodic effect phase was higer than 180 degrees. In turn,
rescale function could return values outised of the logical range of the
HID field.

Fix by using 64 bit signed integer to store the value during calculation
but still return only 32 bit integer.

Closes: https://github.com/JacKeTUs/universal-pidff/issues/116
Fixes: 224ee88fe395 ("Input: add force feedback driver for PID devices")
Cc: stable@vger.kernel.org
Signed-off-by: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/hid/usbhid/hid-pidff.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/hid/usbhid/hid-pidff.c
+++ b/drivers/hid/usbhid/hid-pidff.c
@@ -11,6 +11,7 @@
 #include "hid-pidff.h"
 #include <linux/hid.h>
 #include <linux/input.h>
+#include <linux/math64.h>
 #include <linux/minmax.h>
 #include <linux/slab.h>
 #include <linux/usb.h>
@@ -325,8 +326,10 @@ static s32 pidff_clamp(s32 i, struct hid
  */
 static int pidff_rescale(int i, int max, struct hid_field *field)
 {
-	return i * (field->logical_maximum - field->logical_minimum) / max +
-	       field->logical_minimum;
+	/* 64 bits needed for big values during rescale */
+	s64 result = field->logical_maximum - field->logical_minimum;
+
+	return div_s64(result * i, max) + field->logical_minimum;
 }
 
 /*