diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 2194cce214faa3d7ad2c1f3e165f13798ef82841..4cb870f596dbd48661e11f906b1813e8561e78d9 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -7531,6 +7531,17 @@ static struct btf *btf_get_module_btf(const struct module *module)
 	return btf;
 }
 
+static int check_btf_kconfigs(const struct module *module, const char *feature)
+{
+	if (!module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
+		pr_err("missing vmlinux BTF, cannot register %s\n", feature);
+		return -ENOENT;
+	}
+	if (module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
+		pr_warn("missing module BTF, cannot register %s\n", feature);
+	return 0;
+}
+
 BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags)
 {
 	struct btf *btf = NULL;
@@ -7891,15 +7902,8 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
 	int ret, i;
 
 	btf = btf_get_module_btf(kset->owner);
-	if (!btf) {
-		if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
-			pr_err("missing vmlinux BTF, cannot register kfuncs\n");
-			return -ENOENT;
-		}
-		if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
-			pr_warn("missing module BTF, cannot register kfuncs\n");
-		return 0;
-	}
+	if (!btf)
+		return check_btf_kconfigs(kset->owner, "kfunc");
 	if (IS_ERR(btf))
 		return PTR_ERR(btf);
 
@@ -7999,17 +8003,8 @@ int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_c
 	int ret;
 
 	btf = btf_get_module_btf(owner);
-	if (!btf) {
-		if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
-			pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n");
-			return -ENOENT;
-		}
-		if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
-			pr_err("missing module BTF, cannot register dtor kfuncs\n");
-			return -ENOENT;
-		}
-		return 0;
-	}
+	if (!btf)
+		return check_btf_kconfigs(owner, "dtor kfuncs");
 	if (IS_ERR(btf))
 		return PTR_ERR(btf);
 
diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
index f00c97b2a6b5f6ea4d8f31bf36eb8f53b239c179..18d37d4695c187db8ebefc6af91995c593609239 100755
--- a/tools/testing/selftests/net/mptcp/diag.sh
+++ b/tools/testing/selftests/net/mptcp/diag.sh
@@ -20,7 +20,7 @@ flush_pids()
 
 	ip netns pids "${ns}" | xargs --no-run-if-empty kill -SIGUSR1 &>/dev/null
 
-	for _ in $(seq 10); do
+	for _ in $(seq $((timeout_poll * 10))); do
 		[ -z "$(ip netns pids "${ns}")" ] && break
 		sleep 0.1
 	done
@@ -91,6 +91,15 @@ chk_msk_nr()
 	__chk_msk_nr "grep -c token:" "$@"
 }
 
+chk_listener_nr()
+{
+	local expected=$1
+	local msg="$2"
+
+	__chk_nr "ss -inmlHMON $ns | wc -l" "$expected" "$msg - mptcp" 0
+	__chk_nr "ss -inmlHtON $ns | wc -l" "$expected" "$msg - subflows"
+}
+
 wait_msk_nr()
 {
 	local condition="grep -c token:"
@@ -289,5 +298,24 @@ flush_pids
 chk_msk_inuse 0 "many->0"
 chk_msk_cestab 0 "many->0"
 
+chk_listener_nr 0 "no listener sockets"
+NR_SERVERS=100
+for I in $(seq 1 $NR_SERVERS); do
+	ip netns exec $ns ./mptcp_connect -p $((I + 20001)) \
+		-t ${timeout_poll} -l 0.0.0.0 >/dev/null 2>&1 &
+done
+
+for I in $(seq 1 $NR_SERVERS); do
+	mptcp_lib_wait_local_port_listen $ns $((I + 20001))
+done
+
+chk_listener_nr $NR_SERVERS "many listener sockets"
+
+# graceful termination
+for I in $(seq 1 $NR_SERVERS); do
+	echo a | ip netns exec $ns ./mptcp_connect -p $((I + 20001)) 127.0.0.1 >/dev/null 2>&1 &
+done
+flush_pids
+
 mptcp_lib_result_print_all_tap
 exit $ret
diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index 3777d66fc56d36a4770b164fd781af298cd4eb70..108a1e12436c68af538e04fa7bc3830e4e02d433 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -9,6 +9,7 @@ readonly KSFT_SKIP=4
 readonly KSFT_TEST="${MPTCP_LIB_KSFT_TEST:-$(basename "${0}" .sh)}"
 
 MPTCP_LIB_SUBTESTS=()
+MPTCP_LIB_SUBTESTS_DUPLICATED=0
 
 # only if supported (or forced) and not disabled, see no-color.org
 if { [ -t 1 ] || [ "${SELFTESTS_MPTCP_LIB_COLOR_FORCE:-}" = "1" ]; } &&
@@ -146,12 +147,26 @@ mptcp_lib_kversion_ge() {
 	mptcp_lib_fail_if_expected_feature "kernel version ${1} lower than ${v}"
 }
 
+__mptcp_lib_result_check_duplicated() {
+	local subtest
+
+	for subtest in "${MPTCP_LIB_SUBTESTS[@]}"; do
+		if [[ "${subtest}" == *" - ${KSFT_TEST}: ${*%% #*}" ]]; then
+			MPTCP_LIB_SUBTESTS_DUPLICATED=1
+			mptcp_lib_print_err "Duplicated entry: ${*}"
+			break
+		fi
+	done
+}
+
 __mptcp_lib_result_add() {
 	local result="${1}"
 	shift
 
 	local id=$((${#MPTCP_LIB_SUBTESTS[@]} + 1))
 
+	__mptcp_lib_result_check_duplicated "${*}"
+
 	MPTCP_LIB_SUBTESTS+=("${result} ${id} - ${KSFT_TEST}: ${*}")
 }
 
@@ -206,6 +221,12 @@ mptcp_lib_result_print_all_tap() {
 	for subtest in "${MPTCP_LIB_SUBTESTS[@]}"; do
 		printf "%s\n" "${subtest}"
 	done
+
+	if [ "${MPTCP_LIB_SUBTESTS_DUPLICATED}" = 1 ] &&
+	   mptcp_lib_expect_all_features; then
+		mptcp_lib_print_err "Duplicated test entries"
+		exit ${KSFT_FAIL}
+	fi
 }
 
 # get the value of keyword $1 in the line marked by keyword $2