Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753164AbdFGXEv (ORCPT ); Wed, 7 Jun 2017 19:04:51 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:50651 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753134AbdFGXEt (ORCPT ); Wed, 7 Jun 2017 19:04:49 -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 3.10 163/250] USB: serial: safe_serial: fix information leak in completion handler Date: Thu, 8 Jun 2017 00:59:09 +0200 Message-Id: <1496876436-32402-164-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: 1053 Lines: 35 From: Johan Hovold commit 8c76d7cd520ebffc1ea9ea0850d87a224a50c7f2 upstream. Add missing sanity check to the bulk-in completion handler to avoid an integer underflow that could be triggered by a malicious device. This avoids leaking up to 56 bytes from after the URB transfer buffer to user space. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Johan Hovold Signed-off-by: Willy Tarreau --- drivers/usb/serial/safe_serial.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c index 21cd7bf..8e24f8f 100644 --- a/drivers/usb/serial/safe_serial.c +++ b/drivers/usb/serial/safe_serial.c @@ -215,6 +215,11 @@ static void safe_process_read_urb(struct urb *urb) if (!safe) goto out; + if (length < 2) { + dev_err(&port->dev, "malformed packet\n"); + return; + } + fcs = fcs_compute10(data, length, CRC10_INITFCS); if (fcs) { dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs); -- 2.8.0.rc2.1.gbe9624a