From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f66.google.com ([209.85.215.66]:35410 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932065AbdCFQpT (ORCPT ); Mon, 6 Mar 2017 11:45:19 -0500 From: Johan Hovold To: linux-usb@vger.kernel.org Cc: Johan Hovold , "stable # 2 . 6 . 30" Subject: [PATCH 4/5] USB: serial: io_ti: fix information leak in completion handler Date: Mon, 6 Mar 2017 17:36:40 +0100 Message-Id: <20170306163641.3673-5-johan@kernel.org> In-Reply-To: <20170306163641.3673-1-johan@kernel.org> References: <20170306163641.3673-1-johan@kernel.org> Sender: stable-owner@vger.kernel.org List-ID: Add missing sanity check to the bulk-in completion handler to avoid an integer underflow that can be triggered by a malicious device. This avoids leaking 128 kB of memory content from after the URB transfer buffer to user space. Fixes: 8c209e6782ca ("USB: make actual_length in struct urb field u32") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable # 2.6.30 Signed-off-by: Johan Hovold --- drivers/usb/serial/io_ti.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c index 4561dd4cde8b..a76b95d32157 100644 --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -1761,7 +1761,7 @@ static void edge_bulk_in_callback(struct urb *urb) port_number = edge_port->port->port_number; - if (edge_port->lsr_event) { + if (urb->actual_length > 0 && edge_port->lsr_event) { edge_port->lsr_event = 0; dev_dbg(dev, "%s ===== Port %u LSR Status = %02x, Data = %02x ======\n", __func__, port_number, edge_port->lsr_mask, *data); -- 2.12.0