lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1424992808-29891-3-git-send-email-mgottschlag@gmail.com>
Date:	Fri, 27 Feb 2015 00:20:06 +0100
From:	Mathias Gottschlag <mgottschlag@...il.com>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:	Hans de Goede <hdegoede@...hat.com>, linux-input@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Mathias Gottschlag <mgottschlag@...il.com>
Subject: [PATCHv2 2/4] psmouse: Ensure that the focaltech driver reports consistent coordinates.

We don't know whether x_max or y_max really hold the maximum possible
coordinates, and we don't know for sure whether we correctly interpret the
coordinates sent by the touchpad, so we clamp the reported values to
prevent confusion in userspace code.

Signed-off-by: Mathias Gottschlag <mgottschlag@...il.com>
---
 drivers/input/mouse/focaltech.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/input/mouse/focaltech.c b/drivers/input/mouse/focaltech.c
index 5d8cf98..0cfc646 100644
--- a/drivers/input/mouse/focaltech.c
+++ b/drivers/input/mouse/focaltech.c
@@ -126,9 +126,17 @@ static void focaltech_report_state(struct psmouse *psmouse)
 		input_mt_slot(dev, i);
 		input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
 		if (active) {
-			input_report_abs(dev, ABS_MT_POSITION_X, finger->x);
+			int clamped_x, clamped_y;
+			/*
+			 * The touchpad might report invalid data, so we clamp
+			 * the resulting values so that we do not confuse
+			 * userspace.
+			 */
+			clamped_x = clamp((int)finger->x, 0, (int)priv->x_max);
+			clamped_y = clamp((int)finger->y, 0, (int)priv->y_max);
+			input_report_abs(dev, ABS_MT_POSITION_X, clamped_x);
 			input_report_abs(dev, ABS_MT_POSITION_Y,
-					 priv->y_max - finger->y);
+					 priv->y_max - clamped_y);
 		}
 	}
 	input_mt_report_pointer_emulation(dev, true);
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ