This is a note to let you know that I've just added the patch titled selftests: net: fix tcp listener handling in pmtu.sh to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-net-fix-tcp-listener-handling-in-pmtu.sh.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 685662e3e8d8f1a92798f2b925b0e7004bebd76c Author: Paolo Abeni <pabeni@xxxxxxxxxx> Date: Thu Feb 1 19:42:40 2024 +0100 selftests: net: fix tcp listener handling in pmtu.sh [ Upstream commit e71e016ad0f6e641a7898b8cda5f62f8e2beb2f1 ] The pmtu.sh test uses a few TCP listener in a problematic way: It hard-codes a constant timeout to wait for the listener starting-up in background. That introduces unneeded latency and on very slow and busy host it can fail. Additionally the test starts again the same listener in the same namespace on the same port, just after the previous connection completed. Fast host can attempt starting the new server before the old one really closed the socket. Address the issues using the wait_local_port_listen helper and explicitly waiting for the background listener process exit. Fixes: 136a1b434bbb ("selftests: net: test vxlan pmtu exceptions with tcp") Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Reviewed-by: David Ahern <dsahern@xxxxxxxxxx> Link: https://lore.kernel.org/r/f8e8f6d44427d8c45e9f6a71ee1a321047452087.1706812005.git.pabeni@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh index 3f118e3f1c66..f0febc19baae 100755 --- a/tools/testing/selftests/net/pmtu.sh +++ b/tools/testing/selftests/net/pmtu.sh @@ -199,6 +199,7 @@ # Same as above but with IPv6 source lib.sh +source net_helper.sh PAUSE_ON_FAIL=no VERBOSE=0 @@ -1336,13 +1337,15 @@ test_pmtu_ipvX_over_bridged_vxlanY_or_geneveY_exception() { TCPDST="TCP:[${dst}]:50000" fi ${ns_b} socat -T 3 -u -6 TCP-LISTEN:50000 STDOUT > $tmpoutfile & + local socat_pid=$! - sleep 1 + wait_local_port_listen ${NS_B} 50000 tcp dd if=/dev/zero status=none bs=1M count=1 | ${target} socat -T 3 -u STDIN $TCPDST,connect-timeout=3 size=$(du -sb $tmpoutfile) size=${size%%/tmp/*} + wait ${socat_pid} [ $size -ne 1048576 ] && err "File size $size mismatches exepcted value in locally bridged vxlan test" && return 1 done