HID: core: prevent out-of-bound readings
authorBenjamin Tissoires <benjamin.tissoires@redhat.com>
Tue, 14 Jun 2016 17:55:22 +0000 (10:55 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 15 Sep 2016 06:27:48 +0000 (08:27 +0200)
[ Upstream commit 50220dead1650609206efe91f0cc116132d59b3f ]

Plugging a Logitech DJ receiver with KASAN activated raises a bunch of
out-of-bound readings.

The fields are allocated up to MAX_USAGE, meaning that potentially, we do
not have enough fields to fit the incoming values.
Add checks and silence KASAN.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hid/hid-core.c

index ec791e169f8f7c205e1428bc3887ddd2dece043c..936960202cf488dbeff3d31ea5931d04096c10bd 100644 (file)
@@ -1251,6 +1251,7 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field,
                /* Ignore report if ErrorRollOver */
                if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
                    value[n] >= min && value[n] <= max &&
+                   value[n] - min < field->maxusage &&
                    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
                        goto exit;
        }
@@ -1263,11 +1264,13 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field,
                }
 
                if (field->value[n] >= min && field->value[n] <= max
+                       && field->value[n] - min < field->maxusage
                        && field->usage[field->value[n] - min].hid
                        && search(value, field->value[n], count))
                                hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
 
                if (value[n] >= min && value[n] <= max
+                       && value[n] - min < field->maxusage
                        && field->usage[value[n] - min].hid
                        && search(field->value, value[n], count))
                                hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);