As we process the second byte of a control transfer, transfers of less than 2 bytes must be discarded.

This bug is as old as the driver.

SIgned-off-by: Oliver Neukum oneukum@suse.com CC: stable@vger.kernel.org --- drivers/usb/misc/cypress_cy7c63.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/misc/cypress_cy7c63.c b/drivers/usb/misc/cypress_cy7c63.c index cecd7693b741..75f5a740cba3 100644 --- a/drivers/usb/misc/cypress_cy7c63.c +++ b/drivers/usb/misc/cypress_cy7c63.c @@ -88,6 +88,9 @@ static int vendor_command(struct cypress *dev, unsigned char request, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER, address, data, iobuf, CYPRESS_MAX_REQSIZE, USB_CTRL_GET_TIMEOUT); + /* we must not process garbage */ + if (retval < 2) + goto err_buf;

/* store returned data (more READs to be added) */ switch (request) { @@ -107,6 +110,7 @@ static int vendor_command(struct cypress *dev, unsigned char request, break; }

+err_buf: kfree(iobuf); error: return retval;