skb_clone() dynamically allocates memory and may fail. If it does it
returns NULL. This means we'll dereference a NULL pointer in
drivers/net/usb/cdc_ncm.c::cdc_ncm_rx_fixup().
As far as I can tell, the proper way to deal with this is simply to goto
the error label.

Furthermore gcc complains that 'skb' may be used uninitialized:
  drivers/net/usb/cdc_ncm.c: In function ‘cdc_ncm_rx_fixup’:
  drivers/net/usb/cdc_ncm.c:922:18: warning: ‘skb’ may be used uninitialized in this function
and I believe it is right. On the line where we
  pr_debug("invalid frame detected (ignored)" ...
we are using the local variable 'skb' but nothing has ever been assigned
to that variable yet. I believe the correct fix for that is to use
'skb_in' instead.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The patch provides USB CDC NCM host driver support in the Linux Kernel.

Changes:
drivers/net/usb/cdc_ncm.c:
- initial submission of the CDC NCM host driver;
- verified on Intel 32/64 bit, Intel Atom, ST-Ericsson U8500 (ARM)
- throughput measured over 100 Mbits duplex;
- driver supports 16-bit NTB format only, but it is more than enough for
  transfers up to 64K;
- driver can handle up to 32 datagrams in received NTB;
- timer is used to collect several packets in Tx direction

drivers/net/usb/Kconfig:
- a new entry to compile CDC NCM host driver
drivers/net/usb/Makefile:
- a new entry to compile CDC NCM host driver
Signed-off-by: NAlexey Orishko <alexey.orishko@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>