Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752897AbdDJQLm (ORCPT ); Mon, 10 Apr 2017 12:11:42 -0400 Received: from mx2.suse.de ([195.135.220.15]:37776 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754144AbdDJPeB (ORCPT ); Mon, 10 Apr 2017 11:34:01 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Johan Hovold , Jiri Slaby Subject: [PATCH 3.12 017/142] USB: serial: safe_serial: fix information leak in completion handler Date: Mon, 10 Apr 2017 17:31:38 +0200 Message-Id: <4151dae02b2313c1981c34bd3f0da4febd463ca2.1491838390.git.jslaby@suse.cz> X-Mailer: git-send-email 2.12.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1147 Lines: 39 From: Johan Hovold 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- 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 ba895989d8c4..246cdefa0e88 100644 --- a/drivers/usb/serial/safe_serial.c +++ b/drivers/usb/serial/safe_serial.c @@ -206,6 +206,11 @@ 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); -- 2.12.2