USB: whiteheat: Added bounds checking for bulk command response
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@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index e62f2df..6c3734d 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -514,6 +514,10 @@
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 @@
/* 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;