From 72ea18a558ed7a63a50bb121ba60d73b5b38ae30 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 27 May 2013 14:44:39 +0200 Subject: [PATCH] USB: mos7720: fix DMA to stack The read_mos_reg function is called with stack-allocated buffers, which must not be used for control messages. Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/mos7720.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c index cc0e54345df9..7752cffbf2bc 100644 --- a/drivers/usb/serial/mos7720.c +++ b/drivers/usb/serial/mos7720.c @@ -227,11 +227,22 @@ static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum, __u8 requesttype = (__u8)0xc0; __u16 index = get_reg_index(reg); __u16 value = get_reg_value(reg, serial_portnum); - int status = usb_control_msg(usbdev, pipe, request, requesttype, value, - index, data, 1, MOS_WDR_TIMEOUT); - if (status < 0) + u8 *buf; + int status; + + buf = kmalloc(1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + status = usb_control_msg(usbdev, pipe, request, requesttype, value, + index, buf, 1, MOS_WDR_TIMEOUT); + if (status == 1) + *data = *buf; + else if (status < 0) dev_err(&usbdev->dev, "mos7720: usb_control_msg() failed: %d", status); + kfree(buf); + return status; } -- 2.34.1