Comment 0 for bug 1645278

Upstream stable release 4.4.34 introduced a regression that is already fixed in mainline but hasn't been applied to stable kernels yet (nor to Ubuntu kernels). Here's the thread where the bug was reported:

  http://lkml.iu.edu/hypermail/linux/kernel/1611.2/04851.html

Here's a partial transcript of the report:

 "This update broke PXE boot on our 4-way AMD boxes. The kernel panics in
  eth_type_trans(), presumably during kernel-level IP autoconfiguration,
  see [1]. Bisection points me at 5c67f947 (net: __skb_flow_dissect()
  must cap its return value). And indeed, reverting this commit fixes
  the problem for me."

This issue is fixed with mainline commit:

commit c9b8af1330198ae241cd545e1f040019010d44d9
Author: Eric Dumazet <email address hidden>
Date: Tue Nov 22 11:17:30 2016 -0800

    flow_dissect: call init_default_flow_dissectors() earlier