Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753325AbdFGXkK (ORCPT ); Wed, 7 Jun 2017 19:40:10 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:50592 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753018AbdFGXEc (ORCPT ); Wed, 7 Jun 2017 19:04:32 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Johan Hovold , Jiri Slaby , Willy Tarreau Subject: [PATCH 3.10 168/250] USB: serial: io_ti: fix information leak in completion handler Date: Thu, 8 Jun 2017 00:59:14 +0200 Message-Id: <1496876436-32402-169-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1496876436-32402-1-git-send-email-w@1wt.eu> References: <1496876436-32402-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1247 Lines: 34 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: Jiri Slaby Signed-off-by: Willy Tarreau --- 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 e2dc182..20814d5 100644 --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -1661,7 +1661,7 @@ static void edge_bulk_in_callback(struct urb *urb) port_number = edge_port->port->number - edge_port->port->serial->minor; - 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); -- 2.8.0.rc2.1.gbe9624a