Upstream commit 6185266c5a853bb0f2a459e3ff594546f277609b ("selftests/bpf: Mask bpf_csum_diff() return value to 16 bits in test_verifier") would likely fix this and has been applied to 5.4, 5.8 and 5.11.
5.11 was already released with it.
Ubuntu-5.4.0-73.82, from the cycle that has just ended, should have this fixed too.
Ubuntu-5.8.0-54.61, though, is still going to be promoted to -proposed. But it should have this fixed.
Upstream commit 6185266c5a853bb 0f2a459e3ff5945 46f277609b ("selftests/bpf: Mask bpf_csum_diff() return value to 16 bits in test_verifier") would likely fix this and has been applied to 5.4, 5.8 and 5.11.
5.11 was already released with it.
Ubuntu-5.4.0-73.82, from the cycle that has just ended, should have this fixed too.
Ubuntu-5.8.0-54.61, though, is still going to be promoted to -proposed. But it should have this fixed.