Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features. One of them is the support of MP_FASTCLOSE introduced in commitf284c0c773("mptcp: implement fastclose xmit path"). If the MIB counter is not available, the test cannot be verified and the behaviour will not be the expected one. So we can skip the test if the counter is missing. Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes:01542c9bf9("selftests: mptcp: add fastclose testcase") Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>