From fa825f5c56e50d6a3e620ca183f7a9f6b95f680b Mon Sep 17 00:00:00 2001 From: James Forshaw Date: Sat, 23 Aug 2014 14:39:48 -0700 Subject: [PATCH] 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. Change-Id: I16051930142f75d457faba1d3d32a27d3c1dc475 Signed-off-by: James Forshaw Cc: stable Signed-off-by: Greg Kroah-Hartman --- 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 36a7740e827c..cc5a430dc357 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__); 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) @@ -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; -- 2.34.1