udpgro_fwd.sh from ubuntu_kselftests_net failed with J-5.15 / N-6.8 (all GRO frag list and GRO fwd failed)

[Po-Hsu Lin]

Issue found on N-6.8.0-35.35

All "GRO frag list" and "GRO fwd" related tests failed

Test log:
 Running 'make run_tests -C net TEST_PROGS=udpgro_fwd.sh TEST_GEN_PROGS='' TEST_CUSTOM_PROGS='''
 make: Entering directory '/home/ubuntu/autotest/client/tmp/ubuntu_kselftests_net/src/linux/tools/testing/selftests/net'
 TAP version 13
 1..1
 # timeout set to 0
 # selftests: net: udpgro_fwd.sh
 # IPv4
 # No GRO ok
 # GRO frag list fail - received 10 packets, expected 1
 # GRO fwd fail - received 10 packets, expected 1
 # UDP fwd perf udp rx: 332 MB/s 268432 calls/s
 # udp tx: 590 MB/s 10021 calls/s 10021 msg/s
 # udp rx: 342 MB/s 276877 calls/s
 # udp tx: 592 MB/s 10043 calls/s 10043 msg/s
 # udp rx: 341 MB/s 275968 calls/s
 # udp tx: 592 MB/s 10054 calls/s 10054 msg/s
 # UDP GRO fwd perf udp rx: 328 MB/s 265472 calls/s
 # udp tx: 587 MB/s 9972 calls/s 9972 msg/s
 # udp rx: 340 MB/s 275456 calls/s
 # udp tx: 592 MB/s 10056 calls/s 10056 msg/s
 # udp rx: 339 MB/s 273920 calls/s
 # udp tx: 593 MB/s 10063 calls/s 10063 msg/s
 # GRO frag list over UDP tunnel fail - received 10 packets, expected 1
 # GRO fwd over UDP tunnel fail - received 10 packets, expected 1
 # UDP tunnel fwd perf udp rx: 0 MB/s 256 calls/s
 # udp tx: 364 MB/s 6182 calls/s 6182 msg/s
 # udp tx: 539 MB/s 9154 calls/s 9154 msg/s
 # udp rx: 0 MB/s 256 calls/s
 # udp tx: 564 MB/s 9577 calls/s 9577 msg/s
 # udp rx: 0 MB/s 377 calls/s
 # UDP tunnel GRO fwd perf udp tx: 569 MB/s 9658 calls/s 9658 msg/s
 # udp rx: 0 MB/s 256 calls/s
 # udp tx: 566 MB/s 9605 calls/s 9605 msg/s
 # udp rx: 0 MB/s 256 calls/s
 # udp tx: 569 MB/s 9663 calls/s 9663 msg/s
 # IPv6
 # No GRO ok
 # GRO frag list fail - received 10 packets, expected 1
 # GRO fwd fail - received 10 packets, expected 1
 # UDP fwd perf udp rx: 337 MB/s 272640 calls/s
 # udp tx: 582 MB/s 9881 calls/s 9881 msg/s
 # udp rx: 409 MB/s 331633 calls/s
 # udp tx: 581 MB/s 9863 calls/s 9863 msg/s
 # udp rx: 414 MB/s 335360 calls/s
 # udp tx: 577 MB/s 9795 calls/s 9795 msg/s
 # UDP GRO fwd perf udp rx: 391 MB/s 316416 calls/s
 # udp tx: 586 MB/s 9953 calls/s 9953 msg/s
 # udp rx: 402 MB/s 325632 calls/s
 # udp tx: 589 MB/s 10000 calls/s 10000 msg/s
 # udp rx: 402 MB/s 325632 calls/s
 # udp tx: 589 MB/s 9990 calls/s 9990 msg/s
 # GRO frag list over UDP tunnel fail - received 10 packets, expected 1
 # GRO fwd over UDP tunnel fail - received 10 packets, expected 1
 # UDP tunnel fwd perf udp tx: 459 MB/s 7786 calls/s 7786 msg/s
 # udp rx: 7 MB/s 5888 calls/s
 # udp tx: 447 MB/s 7591 calls/s 7591 msg/s
 # udp rx: 29 MB/s 23552 calls/s
 # udp tx: 570 MB/s 9678 calls/s 9678 msg/s
 # UDP tunnel GRO fwd perf udp rx: 22 MB/s 18432 calls/s
 # udp tx: 577 MB/s 9789 calls/s 9789 msg/s
 # udp rx: 24 MB/s 19456 calls/s
 # udp tx: 580 MB/s 9842 calls/s 9842 msg/s
 # udp tx: 416 MB/s 7064 calls/s 7064 msg/s
 # udp rx: 3 MB/s 2816 calls/s
 not ok 1 selftests: net: udpgro_fwd.sh # exit=1

[Po-Hsu Lin (cypressyew)]

This issue can be found on J-gke-5.15.0-1060.66 as well.

I think the cause is identical to https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/2065369