HID: core: prevent out-of-bound readings
Benjamin Tissoires [Tue, 19 Jan 2016 11:34:58 +0000 (12:34 +0100)]
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.

Bug 1823317

Change-Id: Ib3ba92572acbdd4c9ec265e54a45f92606107700
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Gagan Grover <ggrover@nvidia.com>
Reviewed-on: http://git-master/r/1259928
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vinayak Pane <vpane@nvidia.com>

drivers/hid/hid-core.c

index a6ecac9..3846509 100644 (file)
@@ -1148,6 +1148,7 @@ 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;
        }
@@ -1160,11 +1161,13 @@ 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);