usbnet: ipheth: fix potential null pointer dereference in ipheth_carrier_set

commit 61c59355e0154a938b28710dfa6c1d8be2ddcefa upstream.

_dev_ is being dereferenced before it is null checked, hence there
is a potential null pointer dereference.

Fix this by moving the pointer dereference after _dev_ has been null
checked.

Addresses-Coverity-ID: 1462020
Fixes: bb1b40c7cb86 ("usbnet: ipheth: prevent TX queue timeouts when device not ready")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c
index cefb75f8cc94a6cc8e7c0ea0ccb2627d74015605..01f95d192d253c5ffa6193c1e28e9a6d5447e009 100644 (file)
--- a/drivers/net/usb/ipheth.c
+++ b/drivers/net/usb/ipheth.c
@@ -290,12 +290,15 @@ static void ipheth_sndbulk_callback(struct urb *urb)
 
 static int ipheth_carrier_set(struct ipheth_device *dev)
 {
-       struct usb_device *udev = dev->udev;
+       struct usb_device *udev;
        int retval;
+
        if (!dev)
                return 0;
        if (!dev->confirmed_pairing)
                return 0;
+
+       udev = dev->udev;
        retval = usb_control_msg(udev,
                        usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
                        IPHETH_CMD_CARRIER_CHECK, /* request */