Merge branch 'fragment-stack-oob-read'

Davide Caratti says:

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fix stack OOB read while fragmenting IPv4 packets

- patch 1/2 fixes openvswitch IPv4 fragmentation, that does a stack OOB
read after commit d52e5a7e7ca4 ("ipv4: lock mtu in fnhe when received
PMTU < net.ipv4.route.min_pmt")
- patch 2/2 fixes the same issue in TC 'sch_frag' code
====================

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