usbnet: remove generic hard_header_len check

[ Upstream commit eb85569fe2d06c2fbf4de7b66c263ca095b397aa ]

This patch removes a generic hard_header_len check from the usbnet
module that is causing dropped packages under certain circumstances
for devices that send rx packets that cross urb boundaries.

One example is the AX88772B which occasionally send rx packets that
cross urb boundaries where the remaining partial packet is sent with
no hardware header. When the buffer with a partial packet is of less
number of octets than the value of hard_header_len the buffer is
discarded by the usbnet module.

With AX88772B this can be reproduced by using ping with a packet
size between 1965-1976.

The bug has been reported here:

https://bugzilla.kernel.org/show_bug.cgi?id=29082

This patch introduces the following changes:
- Removes the generic hard_header_len check in the rx_complete
  function in the usbnet module.
- Introduces a ETH_HLEN check for skbs that are not cloned from
  within a rx_fixup callback.
- For safety a hard_header_len check is added to each rx_fixup
  callback function that could be affected by this change.
  These extra checks could possibly be removed by someone
  who has the hardware to test.
- Removes a call to dev_kfree_skb_any() and instead utilizes the
  dev->done list to queue skbs for cleanup.

The changes place full responsibility on the rx_fixup callback
functions that clone skbs to only pass valid skbs to the
usbnet_skb_return function.

Change-Id: Ifa96c21a297be5010022f4e341c99e29832eadf9
Signed-off-by: Emil Goode <emilgoode@gmail.com>
Reported-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: sctp: fix sctp_connectx abi for ia32 emulation/compat mode

[ Upstream commit ffd5939381c609056b33b7585fb05a77b4c695f3 ]

SCTP's sctp_connectx() abi breaks for 64bit kernels compiled with 32bit
emulation (e.g. ia32 emulation or x86_x32). Due to internal usage of
'struct sctp_getaddrs_old' which includes a struct sockaddr pointer,
sizeof(param) check will always fail in kernel as the structure in
64bit kernel space is 4bytes larger than for user binaries compiled
in 32bit mode. Thus, applications making use of sctp_connectx() won't
be able to run under such circumstances.

Introduce a compat interface in the kernel to deal with such
situations by using a 'struct compat_sctp_getaddrs_old' structure
where user data is copied into it, and then sucessively transformed
into a 'struct sctp_getaddrs_old' structure with the help of
compat_ptr(). That fixes sctp_connectx() abi without any changes
needed in user space, and lets the SCTP test suite pass when compiled
in 32bit and run on 64bit kernels.

Change-Id: I8b7d908e53e737b9183adb707c99bf2aa5aa81b9
Fixes: f9c67811ebc0 ("sctp: Fix regression introduced by new sctp_connectx api")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>