cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind

usbnet_link_change will call schedule_work and should be
avoided if bind is failing. Otherwise we will end up with
scheduled work referring to a netdev which has gone away.

Instead of making the call conditional, we can just defer
it to usbnet_probe, using the driver_info flag made for
this purpose.

Fixes: 8a34b0ae8778 ("usbnet: cdc_ncm: apply usbnet_link_change")
Reported-by: Andrey Konovalov <andreyknvl@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index be927964375b724658d97b71f9736ec44c1090d6..86ba30ba35e8fcf45f9eba287334da04b54203e2 100644 (file)
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -988,8 +988,6 @@ EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
 
 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
 {
-       int ret;
-
        /* MBIM backwards compatible function? */
        if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
                return -ENODEV;
@@ -998,16 +996,7 @@ static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
         * Additionally, generic NCM devices are assumed to accept arbitrarily
         * placed NDP.
         */
-       ret = cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
-
-       /*
-        * We should get an event when network connection is "connected" or
-        * "disconnected". Set network connection in "disconnected" state
-        * (carrier is OFF) during attach, so the IP network stack does not
-        * start IPv6 negotiation and more.
-        */
-       usbnet_link_change(dev, 0, 0);
-       return ret;
+       return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
 }
 
 static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
@@ -1590,7 +1579,8 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
 
 static const struct driver_info cdc_ncm_info = {
        .description = "CDC NCM",
-       .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
+       .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
+                       | FLAG_LINK_INTR,
        .bind = cdc_ncm_bind,
        .unbind = cdc_ncm_unbind,
        .manage_power = usbnet_manage_power,
@@ -1603,7 +1593,7 @@ static const struct driver_info cdc_ncm_info = {
 static const struct driver_info wwan_info = {
        .description = "Mobile Broadband Network Device",
        .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
-                       | FLAG_WWAN,
+                       | FLAG_LINK_INTR | FLAG_WWAN,
        .bind = cdc_ncm_bind,
        .unbind = cdc_ncm_unbind,
        .manage_power = usbnet_manage_power,
@@ -1616,7 +1606,7 @@ static const struct driver_info wwan_info = {
 static const struct driver_info wwan_noarp_info = {
        .description = "Mobile Broadband Network Device (NO ARP)",
        .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
-                       | FLAG_WWAN | FLAG_NOARP,
+                       | FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
        .bind = cdc_ncm_bind,
        .unbind = cdc_ncm_unbind,
        .manage_power = usbnet_manage_power,