From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Forshaw Subject: [PATCH 3.16 113/125] USB: whiteheat: Added bounds checking for bulk command response Date: Wed, 3 Sep 2014 15:07:50 -0700 Message-Id: <20140903220627.090666331@linuxfoundation.org> In-Reply-To: <20140903220623.649748296@linuxfoundation.org> References: <20140903220623.649748296@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Forshaw commit 6817ae225cd650fb1c3295d769298c38b1eba818 upstream. This patch fixes a potential security issue in the whiteheat USB driver which might allow a local attacker to cause kernel memory corrpution. This is due to an unchecked memcpy into a fixed size buffer (of 64 bytes). On EHCI and XHCI busses it's possible to craft responses greater than 64 bytes leading a buffer overflow. Signed-off-by: James Forshaw Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/whiteheat.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/usb/serial/whiteheat.c +++ b/drivers/usb/serial/whiteheat.c @@ -514,6 +514,10 @@ static void command_port_read_callback(s dev_dbg(&urb->dev->dev, "%s - command_info is NULL, exiting.\n", __func__); return; } + if (!urb->actual_length) { + dev_dbg(&urb->dev->dev, "%s - empty response, exiting.\n", __func__); + return; + } if (status) { dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n", __func__, status); if (status != -ENOENT) @@ -534,7 +538,8 @@ static void command_port_read_callback(s /* These are unsolicited reports from the firmware, hence no waiting command to wakeup */ dev_dbg(&urb->dev->dev, "%s - event received\n", __func__); - } else if (data[0] == WHITEHEAT_GET_DTR_RTS) { + } else if ((data[0] == WHITEHEAT_GET_DTR_RTS) && + (urb->actual_length - 1 <= sizeof(command_info->result_buffer))) { memcpy(command_info->result_buffer, &data[1], urb->actual_length - 1); command_info->command_finished = WHITEHEAT_CMD_COMPLETE;