[ Upstream commit f9c4845385c8f6631ebd5dddfb019ea7a285fba4 ]
ip_finish_output_gso() may call .ndo_features_check() even before the
skb has a L2 header. This conflicts with qeth_get_ip_version()'s attempt
to inspect the L2 header via vlan_eth_hdr().
Switch to vlan_get_protocol(), as already used further down in the
common qeth_features_check() path.
Fixes: f13ade1993 ("s390/qeth: run non-offload L3 traffic over common xmit path")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>