Commit c2c0e8b2 authored Aug 27, 2014 by David S. Miller

f_ncm: Don't use netdev_start_xmit().



Unfortunately, the USB gadget layer has this weird things where NULL
skbs are passed into ops->ndo_start_xmit() in order to trigger the
dev->wrap() calls to build packets.

This is completely outside of the allowable range of sane arguments
for the ndo_start_xmit method.  All invocations of ndo_start_xmit()
should be with non-NULL SKB arguments.

Put back the direct call, but with a comment explaining how this
is not acceptable in the long term.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 23d2d9a6

drivers/usb/gadget/function/f_ncm.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -1101,7 +1101,15 @@ static void ncm_tx_tasklet(unsigned long data)
		/* Only send if data is available. */
		if (ncm->skb_tx_data) {
		ncm->timer_force_tx = true;
		netdev_start_xmit(NULL, ncm->netdev);

		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
		* XXX is not sane. The gadget layer should be redesigned so
		* XXX that the dev->wrap() invocations to build SKBs is transparent
		* XXX and performed in some way outside of the ndo_start_xmit
		* XXX interface.
		*/
		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);

		ncm->timer_force_tx = false;
		}
		}