Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754501AbdCPPH0 (ORCPT ); Thu, 16 Mar 2017 11:07:26 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60202 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752033AbdCPOcs (ORCPT ); Thu, 16 Mar 2017 10:32:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold Subject: [PATCH 4.4 28/35] USB: serial: io_ti: fix information leak in completion handler Date: Thu, 16 Mar 2017 23:29:47 +0900 Message-Id: <20170316142908.625141396@linuxfoundation.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170316142906.685052998@linuxfoundation.org> References: <20170316142906.685052998@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1167 Lines: 35 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 654b404f2a222f918af9b0cd18ad469d0c941a8e upstream. 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") Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/io_ti.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- 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 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);