selftests/net/ip_defrag.sh fails on mainline since v4.20-rc7-202-g1d51b4b1d3f2

Hi! We've noticed selftests/net/ip_defrag.sh started failing on mainline between v4.20-rc7-23-gab63e725b49c (good) and v4.20-rc7-202-g1d51b4b1d3f2 (bad). Output looks like:

selftests: net: ip_defrag.sh ipv4 defrag PASS seed = 1545325420 ipv4 defrag with overlaps seed = 1545325421 ./ip_defrag: recv: expected timeout; got 2272 not ok 1..16 selftests: net: ip_defrag.sh [FAIL] selftests: net_ip_defrag.sh [FAIL]

I see a lot of net/ changes in the diff - we can bisect it if necessary but wanted to see if anyone else had already investigated.

Thanks, Dan