Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752941AbdFGXER (ORCPT ); Wed, 7 Jun 2017 19:04:17 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:50499 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752915AbdFGXEP (ORCPT ); Wed, 7 Jun 2017 19:04:15 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Johan Hovold , Willy Tarreau Subject: [PATCH 3.10 159/250] USB: serial: digi_acceleport: fix OOB data sanity check Date: Thu, 8 Jun 2017 00:59:05 +0200 Message-Id: <1496876436-32402-160-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: 1847 Lines: 51 From: Johan Hovold commit 2d380889215fe20b8523345649dee0579821800c upstream. Make sure to check for short transfers to avoid underflow in a loop condition when parsing the receive buffer. Also fix an off-by-one error in the incomplete sanity check which could lead to invalid data being parsed. Fixes: 8c209e6782ca ("USB: make actual_length in struct urb field u32") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Willy Tarreau --- drivers/usb/serial/digi_acceleport.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c index 8c34d9c..15b9cb3 100644 --- a/drivers/usb/serial/digi_acceleport.c +++ b/drivers/usb/serial/digi_acceleport.c @@ -1489,16 +1489,20 @@ static int digi_read_oob_callback(struct urb *urb) struct usb_serial *serial = port->serial; struct tty_struct *tty; struct digi_port *priv = usb_get_serial_port_data(port); + unsigned char *buf = urb->transfer_buffer; int opcode, line, status, val; int i; unsigned int rts; + if (urb->actual_length < 4) + return -1; + /* handle each oob command */ - for (i = 0; i < urb->actual_length - 3;) { - opcode = ((unsigned char *)urb->transfer_buffer)[i++]; - line = ((unsigned char *)urb->transfer_buffer)[i++]; - status = ((unsigned char *)urb->transfer_buffer)[i++]; - val = ((unsigned char *)urb->transfer_buffer)[i++]; + for (i = 0; i < urb->actual_length - 4; i += 4) { + opcode = buf[i]; + line = buf[i + 1]; + status = buf[i + 2]; + val = buf[i + 3]; dev_dbg(&port->dev, "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d\n", opcode, line, status, val); -- 2.8.0.rc2.1.gbe9624a