Merge branch 'ipv4-relax-source-validation-check-for-loopback-packets'

Cong Wang says:

====================
ipv4: relax source validation check for loopback packets

This patchset fixes a corner case when loopback packets get dropped
by rp_filter when we route them from veth to lo. Patch 1 is the fix
and patch 2 provides a simplified test case for this scenario.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>