[PATCH 3.16 066/357] HID: magicmouse: sanity check report size in raw_event() callback

From: Greg Kroah-Hartman
Date: Fri Oct 03 2014 - 17:42:50 EST


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

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

From: Jiri Kosina <jkosina@xxxxxxx>

commit c54def7bd64d7c0b6993336abcffb8444795bf38 upstream.

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.

Reported-by: Steven Vittitoe <scvitti@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/hid/hid-magicmouse.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -290,6 +290,11 @@ static int magicmouse_raw_event(struct h
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 h
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);


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