A short control transfer would currently fail to be detected, something
which could lead to stale buffer data being used as valid input.
Check for short transfers, and make sure to log any transfer errors.
Fixes: 6ce76104781a ("USB: Driver for CH341 USB-serial adaptor")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/serial/ch341.c | 32 +++++++++++++++++++++-----------
1 file changed, 21 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 74d21171d22a..2d07fa037f02 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -112,6 +112,8 @@ static int ch341_control_out(struct usb_device *dev, u8 request,
r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
value, index, NULL, 0, DEFAULT_TIMEOUT);
+ if (r < 0)
+ dev_err(&dev->dev, "failed to send control message: %d\n", r);
return r;
}
@@ -129,7 +131,20 @@ static int ch341_control_in(struct usb_device *dev,
r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
value, index, buf, bufsize, DEFAULT_TIMEOUT);
- return r;
+ if (r < bufsize) {
+ if (r >= 0) {
+ dev_err(&dev->dev,
+ "short control message received (%d < %u)\n",
+ r, bufsize);
+ r = -EIO;
+ }
+
+ dev_err(&dev->dev, "failed to receive control message: %d\n",
+ r);
+ return r;
+ }
+
+ return 0;
}
static int ch341_init_set_baudrate(struct usb_device *dev,
@@ -170,9 +185,9 @@ static int ch341_set_handshake(struct usb_device *dev, u8 control)
static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
{
+ const unsigned int size = 2;
char *buffer;
int r;
- const unsigned size = 8;
unsigned long flags;
buffer = kmalloc(size, GFP_KERNEL);
@@ -183,14 +198,9 @@ static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
if (r < 0)
goto out;
- /* setup the private status if available */
- if (r == 2) {
- r = 0;
- spin_lock_irqsave(&priv->lock, flags);
- priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
- spin_unlock_irqrestore(&priv->lock, flags);
- } else
- r = -EPROTO;
+ spin_lock_irqsave(&priv->lock, flags);
+ priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
+ spin_unlock_irqrestore(&priv->lock, flags);
out: kfree(buffer);
return r;
@@ -200,9 +210,9 @@ out: kfree(buffer);
static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
{
+ const unsigned int size = 2;
char *buffer;
int r;
- const unsigned size = 8;
u8 lcr;
buffer = kmalloc(size, GFP_KERNEL);
--
2.10.2
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