[3.13.y.z extended stable] Patch "USB: whiteheat: Added bounds checking for bulk command response" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Mon Sep 22 19:00:05 UTC 2014

This is a note to let you know that I have just added a patch titled

    USB: whiteheat: Added bounds checking for bulk command response

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:


This patch is scheduled to be released in version

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see



>From 820644e90a97f4304219ef3ae9fd8480bb041b06 Mon Sep 17 00:00:00 2001
From: James Forshaw <forshaw at google.com>
Date: Sat, 23 Aug 2014 14:39:48 -0700
Subject: USB: whiteheat: Added bounds checking for bulk command response

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 <forshaw at google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
 drivers/usb/serial/whiteheat.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index 36a7740..cc5a430 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -521,6 +521,10 @@ static void command_port_read_callback(struct urb *urb)
 		dev_dbg(&urb->dev->dev, "%s - command_info is NULL, exiting.\n", __func__);
+	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)
@@ -541,7 +545,8 @@ static void command_port_read_callback(struct urb *urb)
 		/* 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;

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