1 files changed, 67 insertions, 0 deletions
diff --git a/tools/testing/selftests/drivers/net/netcons_overflow.sh b/tools/testing/selftests/drivers/net/netcons_overflow.sh
new file mode 100755
index 000000000000..29bad56448a2
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/netcons_overflow.sh
@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This test verifies that users can successfully create up to
+# MAX_USERDATA_ITEMS userdata entries without encountering any failures.
+#
+# Additionally, it tests for expected failure when attempting to exceed this
+# maximum limit.
+#
+# Author: Breno Leitao <leitao@debian.org>
+
+set -euo pipefail
+
+SCRIPTDIR=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")
+
+source "${SCRIPTDIR}"/lib/sh/lib_netcons.sh
+# This is coming from netconsole code. Check for it in drivers/net/netconsole.c
+MAX_USERDATA_ITEMS=16
+
+# Function to create userdata entries
+function create_userdata_max_entries() {
+	# All these keys should be created without any error
+	for i in $(seq $MAX_USERDATA_ITEMS)
+	do
+		# USERDATA_KEY is used by set_user_data
+		USERDATA_KEY="key"${i}
+		set_user_data
+	done
+}
+
+# Function to verify the entry limit
+function verify_entry_limit() {
+	# Allowing the test to fail without exiting, since the next command
+	# will fail
+	set +e
+	mkdir "${NETCONS_PATH}/userdata/key_that_will_fail" 2> /dev/null
+	ret="$?"
+	set -e
+	if [ "$ret" -eq 0 ];
+	then
+		echo "Adding more than ${MAX_USERDATA_ITEMS} entries in userdata should fail, but it didn't" >&2
+		ls "${NETCONS_PATH}/userdata/" >&2
+		exit "${ksft_fail}"
+	fi
+}
+
+# ========== #
+# Start here #
+# ========== #
+
+modprobe netdevsim 2> /dev/null || true
+modprobe netconsole 2> /dev/null || true
+
+# Check for basic system dependency and exit if not found
+check_for_dependencies
+
+# Remove the namespace, interfaces and netconsole target on exit
+trap cleanup EXIT
+# Create one namespace and two interfaces
+set_network
+# Create a dynamic target for netconsole
+create_dynamic_target
+# populate the maximum number of supported keys in userdata
+create_userdata_max_entries
+# Verify an additional entry is not allowed
+verify_entry_limit
+exit "${ksft_pass}"