[Trusty][Utopic][CVE-2014-3181] HID: magicmouse: sanity check report size in raw_event() callback

Luis Henriques luis.henriques at canonical.com
Mon Sep 22 16:08:26 UTC 2014


From: Jiri Kosina <jkosina at suse.cz>

The report passed to us from transport driver could potentially be
arbitrarily large, therefore we better sanity-check it so that
magicmouse_emit_touch() gets only valid values of raw_id.

Cc: stable at vger.kernel.org
Reported-by: Steven Vittitoe <scvitti at google.com>
Signed-off-by: Jiri Kosina <jkosina at suse.cz>
(cherry picked from commit c54def7bd64d7c0b6993336abcffb8444795bf38)
CVE-2014-3181
BugLink: http://bugs.launchpad.net/bugs/1370025
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/hid/hid-magicmouse.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
index 3b43d1cfa936..991ba79cfc72 100644
--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -290,6 +290,11 @@ static int magicmouse_raw_event(struct hid_device *hdev,
 		if (size < 4 || ((size - 4) % 9) != 0)
 			return 0;
 		npoints = (size - 4) / 9;
+		if (npoints > 15) {
+			hid_warn(hdev, "invalid size value (%d) for TRACKPAD_REPORT_ID\n",
+					size);
+			return 0;
+		}
 		msc->ntouches = 0;
 		for (ii = 0; ii < npoints; ii++)
 			magicmouse_emit_touch(msc, ii, data + ii * 9 + 4);
@@ -307,6 +312,11 @@ static int magicmouse_raw_event(struct hid_device *hdev,
 		if (size < 6 || ((size - 6) % 8) != 0)
 			return 0;
 		npoints = (size - 6) / 8;
+		if (npoints > 15) {
+			hid_warn(hdev, "invalid size value (%d) for MOUSE_REPORT_ID\n",
+					size);
+			return 0;
+		}
 		msc->ntouches = 0;
 		for (ii = 0; ii < npoints; ii++)
 			magicmouse_emit_touch(msc, ii, data + ii * 8 + 6);
-- 
2.1.0





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