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* FAILED: patch "[PATCH] HID: pidff: Fix integer overflow in pidff_rescale" failed to apply to 6.12-stable tree
@ 2026-05-15  5:23 gregkh
  0 siblings, 0 replies; only message in thread
From: gregkh @ 2026-05-15  5:23 UTC (permalink / raw)
  To: tomasz.pakula.oficjalny, jkosina; +Cc: stable


The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 48d1677779ad6816978ad4a4f7588aec5ec960fe
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051522-deflate-sulfur-8341@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 48d1677779ad6816978ad4a4f7588aec5ec960fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Paku=C5=82a?= <tomasz.pakula.oficjalny@gmail.com>
Date: Sun, 10 May 2026 14:23:52 +0200
Subject: [PATCH] HID: pidff: Fix integer overflow in pidff_rescale
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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>

diff --git a/drivers/hid/usbhid/hid-pidff.c b/drivers/hid/usbhid/hid-pidff.c
index aee8a4443305..c45f182d0448 100644
--- 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/stringify.h>
@@ -326,8 +327,10 @@ static s32 pidff_clamp(s32 i, struct hid_field *field)
  */
 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;
 }
 
 /*


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2026-05-15  5:23 FAILED: patch "[PATCH] HID: pidff: Fix integer overflow in pidff_rescale" failed to apply to 6.12-stable tree gregkh

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