FAILED: patch "[PATCH] HID: multitouch: fix out-of-bounds bit access on mt_io_flags" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] HID: multitouch: fix out-of-bounds bit access on mt_io_flags" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 8813b0612275cc61fe9e6603d0ee019247ade6be
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071419-refined-abrasion-5918@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 8813b0612275cc61fe9e6603d0ee019247ade6be Mon Sep 17 00:00:00 2001
From: Trung Nguyen <trungnh@cystack.net>
Date: Thu, 2 Jul 2026 00:13:19 +0700
Subject: [PATCH] HID: multitouch: fix out-of-bounds bit access on mt_io_flags

mt_io_flags is a single unsigned long, but mt_process_slot(),
mt_release_pending_palms() and mt_release_contacts() use it as a
per-slot bitmap indexed by the slot number. That slot number is only
bounded by td->maxcontacts, which is taken from the device's
ContactCountMaximum feature report and can be up to 255, not by
BITS_PER_LONG.

As a result, a multitouch device that advertises a large contact count
makes set_bit()/clear_bit() operate past the mt_io_flags word and
corrupt the adjacent members of struct mt_device. The sticky-fingers
release timer is the easiest way to reach this. mt_release_contacts()
runs

	for (i = 0; i < mt->num_slots; i++)
		clear_bit(i, &td->mt_io_flags);

with num_slots == maxcontacts. For maxcontacts around 250 the loop
clears the bits that overlap td->applications.next, zeroing that list
head, and the list_for_each_entry() that immediately follows then
dereferences NULL. The kernel panics from timer (softirq) context. On a
KASAN build this shows up as a general protection fault in
mt_release_contacts() with a null-ptr-deref at offset 0x58, which is
offsetof(struct mt_application, num_received).

The state is reachable from an untrusted USB or Bluetooth HID
multitouch device; no local privileges are required.

Store the per-slot active state in a separately allocated bitmap sized
for maxcontacts, the same pattern already used for pending_palm_slots,
and keep only MT_IO_FLAGS_RUNNING in mt_io_flags. The two
"mt_io_flags & MT_IO_SLOTS_MASK" arming checks become
bitmap_empty(td->active_slots, td->maxcontacts).

Move MT_IO_FLAGS_RUNNING back to bit 0. It was bumped to bit 32 by the
same commit to leave the low byte for the slot bits; with the slot bits
gone it fits in bit 0 again, which also keeps it within the unsigned
long on 32-bit.

Fixes: 46f781e0d151 ("HID: multitouch: fix sticky fingers")
Cc: stable@vger.kernel.org
Signed-off-by: Trung Nguyen <trungnh@cystack.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 0495152091e3..edb37b4c867e 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -31,6 +31,7 @@
  * [1] https://gitlab.freedesktop.org/libevdev/hid-tools
  */
 
+#include <linux/bitmap.h>
 #include <linux/bits.h>
 #include <linux/device.h>
 #include <linux/hid.h>
@@ -97,8 +98,7 @@ enum report_mode {
 	TOUCHPAD_REPORT_ALL = TOUCHPAD_REPORT_BUTTONS | TOUCHPAD_REPORT_CONTACTS,
 };
 
-#define MT_IO_SLOTS_MASK		GENMASK(7, 0) /* reserve first 8 bits for slot tracking */
-#define MT_IO_FLAGS_RUNNING		32
+#define MT_IO_FLAGS_RUNNING		0
 
 static const bool mtrue = true;		/* default for true */
 static const bool mfalse;		/* default for false */
@@ -174,10 +174,9 @@ struct mt_device {
 	struct timer_list release_timer;	/* to release sticky fingers */
 	struct hid_haptic_device *haptic;	/* haptic related configuration */
 	struct hid_device *hdev;	/* hid_device we're attached to */
-	unsigned long mt_io_flags;	/* mt flags (MT_IO_FLAGS_RUNNING)
-					 * first 8 bits are reserved for keeping the slot
-					 * states, this is fine because we only support up
-					 * to 250 slots (MT_MAX_MAXCONTACT)
+	unsigned long mt_io_flags;	/* mt flags (MT_IO_FLAGS_RUNNING) */
+	unsigned long *active_slots;	/* bitmap of slots with an active
+					 * contact, sized for maxcontacts
 					 */
 	__u8 inputmode_value;	/* InputMode HID feature value */
 	__u8 maxcontacts;
@@ -1036,7 +1035,7 @@ static void mt_release_pending_palms(struct mt_device *td,
 
 	for_each_set_bit(slotnum, app->pending_palm_slots, td->maxcontacts) {
 		clear_bit(slotnum, app->pending_palm_slots);
-		clear_bit(slotnum, &td->mt_io_flags);
+		clear_bit(slotnum, td->active_slots);
 
 		input_mt_slot(input, slotnum);
 		input_mt_report_slot_inactive(input);
@@ -1247,9 +1246,9 @@ static int mt_process_slot(struct mt_device *td, struct input_dev *input,
 		input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
 		input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
 
-		set_bit(slotnum, &td->mt_io_flags);
+		set_bit(slotnum, td->active_slots);
 	} else {
-		clear_bit(slotnum, &td->mt_io_flags);
+		clear_bit(slotnum, td->active_slots);
 	}
 
 	return 0;
@@ -1384,7 +1383,7 @@ static void mt_touch_report(struct hid_device *hid,
 	 * defect.
 	 */
 	if (app->quirks & MT_QUIRK_STICKY_FINGERS) {
-		if (td->mt_io_flags & MT_IO_SLOTS_MASK)
+		if (!bitmap_empty(td->active_slots, td->maxcontacts))
 			mod_timer(&td->release_timer,
 				  jiffies + msecs_to_jiffies(100));
 		else
@@ -1443,6 +1442,15 @@ static int mt_touch_input_configured(struct hid_device *hdev,
 	if (td->is_pressurepad)
 		__set_bit(INPUT_PROP_PRESSUREPAD, input->propbit);
 
+	if (!td->active_slots) {
+		td->active_slots = devm_kcalloc(&td->hdev->dev,
+						BITS_TO_LONGS(td->maxcontacts),
+						sizeof(long),
+						GFP_KERNEL);
+		if (!td->active_slots)
+			return -ENOMEM;
+	}
+
 	app->pending_palm_slots = devm_kcalloc(&hi->input->dev,
 					       BITS_TO_LONGS(td->maxcontacts),
 					       sizeof(long),
@@ -2062,7 +2070,7 @@ static void mt_release_contacts(struct hid_device *hid)
 			for (i = 0; i < mt->num_slots; i++) {
 				input_mt_slot(input_dev, i);
 				input_mt_report_slot_inactive(input_dev);
-				clear_bit(i, &td->mt_io_flags);
+				clear_bit(i, td->active_slots);
 			}
 			input_mt_sync_frame(input_dev);
 			input_sync(input_dev);
@@ -2085,7 +2093,7 @@ static void mt_expired_timeout(struct timer_list *t)
 	 */
 	if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))
 		return;
-	if (td->mt_io_flags & MT_IO_SLOTS_MASK)
+	if (!bitmap_empty(td->active_slots, td->maxcontacts))
 		mt_release_contacts(hdev);
 	clear_bit_unlock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
 }

[PATCH 5.10.y 1/2] HID: add haptics page defines

[Sasha Levin]

From: Angela Czubak <aczubak@google.com>

[ Upstream commit 5e0ae59159e3a07391a35865bb79ff335473fa79 ]

Introduce haptic usages as defined in HID Usage Tables specification.
Add HID units for newton and gram.

Signed-off-by: Angela Czubak <aczubak@google.com>
Co-developed-by: Jonathan Denose <jdenose@google.com>
Signed-off-by: Jonathan Denose <jdenose@google.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Stable-dep-of: 8813b0612275 ("HID: multitouch: fix out-of-bounds bit access on mt_io_flags")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/linux/hid.h | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/include/linux/hid.h b/include/linux/hid.h
index aaae2fecd4ae6e..8a105caf6bcb2d 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -152,6 +152,7 @@ struct hid_item {
 #define HID_UP_TELEPHONY	0x000b0000
 #define HID_UP_CONSUMER		0x000c0000
 #define HID_UP_DIGITIZER	0x000d0000
+#define HID_UP_HAPTIC		0x000e0000
 #define HID_UP_PID		0x000f0000
 #define HID_UP_HPVENDOR         0xff7f0000
 #define HID_UP_HPVENDOR2        0xff010000
@@ -299,6 +300,28 @@ struct hid_item {
 #define HID_DG_TOOLSERIALNUMBER	0x000d005b
 #define HID_DG_LATENCYMODE	0x000d0060
 
+#define HID_HP_SIMPLECONTROLLER	0x000e0001
+#define HID_HP_WAVEFORMLIST	0x000e0010
+#define HID_HP_DURATIONLIST	0x000e0011
+#define HID_HP_AUTOTRIGGER	0x000e0020
+#define HID_HP_MANUALTRIGGER	0x000e0021
+#define HID_HP_AUTOTRIGGERASSOCIATEDCONTROL 0x000e0022
+#define HID_HP_INTENSITY	0x000e0023
+#define HID_HP_REPEATCOUNT	0x000e0024
+#define HID_HP_RETRIGGERPERIOD	0x000e0025
+#define HID_HP_WAVEFORMVENDORPAGE	0x000e0026
+#define HID_HP_WAVEFORMVENDORID	0x000e0027
+#define HID_HP_WAVEFORMCUTOFFTIME	0x000e0028
+#define HID_HP_WAVEFORMNONE	0x000e1001
+#define HID_HP_WAVEFORMSTOP	0x000e1002
+#define HID_HP_WAVEFORMCLICK	0x000e1003
+#define HID_HP_WAVEFORMBUZZCONTINUOUS	0x000e1004
+#define HID_HP_WAVEFORMRUMBLECONTINUOUS	0x000e1005
+#define HID_HP_WAVEFORMPRESS	0x000e1006
+#define HID_HP_WAVEFORMRELEASE	0x000e1007
+#define HID_HP_VENDORWAVEFORMMIN	0x000e2001
+#define HID_HP_VENDORWAVEFORMMAX	0x000e2fff
+
 #define HID_VD_ASUS_CUSTOM_MEDIA_KEYS	0xff310076
 /*
  * HID report types --- Ouch! HID spec says 1 2 3!
@@ -384,6 +407,12 @@ struct hid_item {
 #define HID_REPORT_PROTOCOL	1
 #define HID_BOOT_PROTOCOL	0
 
+/*
+ * HID units
+ */
+#define HID_UNIT_GRAM		0x0101
+#define HID_UNIT_NEWTON		0xe111
+
 /*
  * This is the global environment of the parser. This information is
  * persistent for main-items. The global environment can be saved and
-- 
2.53.0

[PATCH 5.10.y 2/2] HID: multitouch: fix out-of-bounds bit access on mt_io_flags

[Sasha Levin]

From: Trung Nguyen <trungnh@cystack.net>

[ Upstream commit 8813b0612275cc61fe9e6603d0ee019247ade6be ]

mt_io_flags is a single unsigned long, but mt_process_slot(),
mt_release_pending_palms() and mt_release_contacts() use it as a
per-slot bitmap indexed by the slot number. That slot number is only
bounded by td->maxcontacts, which is taken from the device's
ContactCountMaximum feature report and can be up to 255, not by
BITS_PER_LONG.

As a result, a multitouch device that advertises a large contact count
makes set_bit()/clear_bit() operate past the mt_io_flags word and
corrupt the adjacent members of struct mt_device. The sticky-fingers
release timer is the easiest way to reach this. mt_release_contacts()
runs

	for (i = 0; i < mt->num_slots; i++)
		clear_bit(i, &td->mt_io_flags);

with num_slots == maxcontacts. For maxcontacts around 250 the loop
clears the bits that overlap td->applications.next, zeroing that list
head, and the list_for_each_entry() that immediately follows then
dereferences NULL. The kernel panics from timer (softirq) context. On a
KASAN build this shows up as a general protection fault in
mt_release_contacts() with a null-ptr-deref at offset 0x58, which is
offsetof(struct mt_application, num_received).

The state is reachable from an untrusted USB or Bluetooth HID
multitouch device; no local privileges are required.

Store the per-slot active state in a separately allocated bitmap sized
for maxcontacts, the same pattern already used for pending_palm_slots,
and keep only MT_IO_FLAGS_RUNNING in mt_io_flags. The two
"mt_io_flags & MT_IO_SLOTS_MASK" arming checks become
bitmap_empty(td->active_slots, td->maxcontacts).

Move MT_IO_FLAGS_RUNNING back to bit 0. It was bumped to bit 32 by the
same commit to leave the low byte for the slot bits; with the slot bits
gone it fits in bit 0 again, which also keeps it within the unsigned
long on 32-bit.

Fixes: 46f781e0d151 ("HID: multitouch: fix sticky fingers")
Cc: stable@vger.kernel.org
Signed-off-by: Trung Nguyen <trungnh@cystack.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hid/hid-multitouch.c | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index c3bcc23d7c7ca1..e4b91c0866bb98 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -31,6 +31,7 @@
  * [1] https://gitlab.freedesktop.org/libevdev/hid-tools
  */
 
+#include <linux/bitmap.h>
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/module.h>
@@ -81,8 +82,7 @@ enum latency_mode {
 	HID_LATENCY_HIGH = 1,
 };
 
-#define MT_IO_SLOTS_MASK		GENMASK(7, 0) /* reserve first 8 bits for slot tracking */
-#define MT_IO_FLAGS_RUNNING		32
+#define MT_IO_FLAGS_RUNNING		0
 
 static const bool mtrue = true;		/* default for true */
 static const bool mfalse;		/* default for false */
@@ -158,10 +158,9 @@ struct mt_device {
 	struct mt_class mtclass;	/* our mt device class */
 	struct timer_list release_timer;	/* to release sticky fingers */
 	struct hid_device *hdev;	/* hid_device we're attached to */
-	unsigned long mt_io_flags;	/* mt flags (MT_IO_FLAGS_RUNNING)
-					 * first 8 bits are reserved for keeping the slot
-					 * states, this is fine because we only support up
-					 * to 250 slots (MT_MAX_MAXCONTACT)
+	unsigned long mt_io_flags;	/* mt flags (MT_IO_FLAGS_RUNNING) */
+	unsigned long *active_slots;	/* bitmap of slots with an active
+					 * contact, sized for maxcontacts
 					 */
 	__u8 inputmode_value;	/* InputMode HID feature value */
 	__u8 maxcontacts;
@@ -915,7 +914,7 @@ static void mt_release_pending_palms(struct mt_device *td,
 
 	for_each_set_bit(slotnum, app->pending_palm_slots, td->maxcontacts) {
 		clear_bit(slotnum, app->pending_palm_slots);
-		clear_bit(slotnum, &td->mt_io_flags);
+		clear_bit(slotnum, td->active_slots);
 
 		input_mt_slot(input, slotnum);
 		input_mt_report_slot_inactive(input);
@@ -1100,9 +1099,9 @@ static int mt_process_slot(struct mt_device *td, struct input_dev *input,
 		input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
 		input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
 
-		set_bit(slotnum, &td->mt_io_flags);
+		set_bit(slotnum, td->active_slots);
 	} else {
-		clear_bit(slotnum, &td->mt_io_flags);
+		clear_bit(slotnum, td->active_slots);
 	}
 
 	return 0;
@@ -1237,7 +1236,7 @@ static void mt_touch_report(struct hid_device *hid,
 	 * defect.
 	 */
 	if (app->quirks & MT_QUIRK_STICKY_FINGERS) {
-		if (td->mt_io_flags & MT_IO_SLOTS_MASK)
+		if (!bitmap_empty(td->active_slots, td->maxcontacts))
 			mod_timer(&td->release_timer,
 				  jiffies + msecs_to_jiffies(100));
 		else
@@ -1277,6 +1276,15 @@ static int mt_touch_input_configured(struct hid_device *hdev,
 	if (td->is_buttonpad)
 		__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
 
+	if (!td->active_slots) {
+		td->active_slots = devm_kcalloc(&td->hdev->dev,
+						BITS_TO_LONGS(td->maxcontacts),
+						sizeof(long),
+						GFP_KERNEL);
+		if (!td->active_slots)
+			return -ENOMEM;
+	}
+
 	app->pending_palm_slots = devm_kcalloc(&hi->input->dev,
 					       BITS_TO_LONGS(td->maxcontacts),
 					       sizeof(long),
@@ -1655,7 +1663,7 @@ static void mt_release_contacts(struct hid_device *hid)
 			for (i = 0; i < mt->num_slots; i++) {
 				input_mt_slot(input_dev, i);
 				input_mt_report_slot_inactive(input_dev);
-				clear_bit(i, &td->mt_io_flags);
+				clear_bit(i, td->active_slots);
 			}
 			input_mt_sync_frame(input_dev);
 			input_sync(input_dev);
@@ -1678,7 +1686,7 @@ static void mt_expired_timeout(struct timer_list *t)
 	 */
 	if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))
 		return;
-	if (td->mt_io_flags & MT_IO_SLOTS_MASK)
+	if (!bitmap_empty(td->active_slots, td->maxcontacts))
 		mt_release_contacts(hdev);
 	clear_bit_unlock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
 }
-- 
2.53.0