watchdog: pcwd_usb: Use allocated buffer for usb_control_msg
authorGuenter Roeck <linux@roeck-us.net>
Mon, 14 Oct 2013 16:29:34 +0000 (09:29 -0700)
committerWim Van Sebroeck <wim@iguana.be>
Sun, 17 Nov 2013 18:37:48 +0000 (19:37 +0100)
usb_control_msg() must use a dma-capable buffer.

This fixes the following error reported by smatch:

drivers/watchdog/pcwd_usb.c:257 usb_pcwd_send_command() error: doing dma on the
stack (buf)

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/pcwd_usb.c

index 7b14d184792705d3b60ea6fba20041be351a186d..115a0ebebf4acdbded5cd73012c9b32701ff3789 100644 (file)
@@ -235,13 +235,17 @@ static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
                unsigned char cmd, unsigned char *msb, unsigned char *lsb)
 {
        int got_response, count;
-       unsigned char buf[6];
+       unsigned char *buf;
 
        /* We will not send any commands if the USB PCWD device does
         * not exist */
        if ((!usb_pcwd) || (!usb_pcwd->exists))
                return -1;
 
+       buf = kmalloc(6, GFP_KERNEL);
+       if (buf == NULL)
+               return 0;
+
        /* The USB PC Watchdog uses a 6 byte report format.
         * The board currently uses only 3 of the six bytes of the report. */
        buf[0] = cmd;                   /* Byte 0 = CMD */
@@ -277,6 +281,8 @@ static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
                *lsb = usb_pcwd->cmd_data_lsb;
        }
 
+       kfree(buf);
+
        return got_response;
 }