#!/usr/bin/env bash# SPDX-License-Identifier: GPL-2.0## Test the "inc" interpreter.## See include/uapi/linux/securebits.h, include/uapi/linux/fcntl.h and# samples/check-exec/inc.c## Copyright © 2024 Microsoft Corporation set -u -e -o pipefail EXPECTED_OUTPUT="1"exec 2>/dev/null DIR="$(dirname $(readlink -f "$0"))"source "${DIR}"/../kselftest/ktap_helpers.sh exec_direct() {	local expect="$1"	local script="$2"	shift 2	local ret=0	local out 	# Updates PATH for `env` to execute the `inc` interpreter.	out="$(PATH="." "$@" "${script}")" || ret=$? 	if [[ ${ret} -ne ${expect} ]]; then		echo "ERROR: Wrong expectation for direct file execution: ${ret}"		return 1	fi	if [[ ${ret} -eq 0 && "${out}" != "${EXPECTED_OUTPUT}" ]]; then		echo "ERROR: Wrong output for direct file execution: ${out}"		return 1	fi} exec_indirect() {	local expect="$1"	local script="$2"	shift 2	local ret=0	local out 	# Script passed as argument.	out="$("$@" ./inc "${script}")" || ret=$? 	if [[ ${ret} -ne ${expect} ]]; then		echo "ERROR: Wrong expectation for indirect file execution: ${ret}"		return 1	fi	if [[ ${ret} -eq 0 && "${out}" != "${EXPECTED_OUTPUT}" ]]; then		echo "ERROR: Wrong output for indirect file execution: ${out}"		return 1	fi} exec_stdin_reg() {	local expect="$1"	local script="$2"	shift 2	local ret=0	local out 	# Executing stdin must be allowed if the related file is executable.	out="$("$@" ./inc -i < "${script}")" || ret=$? 	if [[ ${ret} -ne ${expect} ]]; then		echo "ERROR: Wrong expectation for stdin regular file execution: ${ret}"		return 1	fi	if [[ ${ret} -eq 0 && "${out}" != "${EXPECTED_OUTPUT}" ]]; then		echo "ERROR: Wrong output for stdin regular file execution: ${out}"		return 1	fi} exec_stdin_pipe() {	local expect="$1"	shift	local ret=0	local out 	# A pipe is not executable.	out="$(cat script-exec.inc | "$@" ./inc -i)" || ret=$? 	if [[ ${ret} -ne ${expect} ]]; then		echo "ERROR: Wrong expectation for stdin pipe execution: ${ret}"		return 1	fi} exec_argument() {	local expect="$1"	local ret=0	shift	local out 	# Script not coming from a file must not be executed.	out="$("$@" ./inc -c "$(< script-exec.inc)")" || ret=$? 	if [[ ${ret} -ne ${expect} ]]; then		echo "ERROR: Wrong expectation for arbitrary argument execution: ${ret}"		return 1	fi	if [[ ${ret} -eq 0 && "${out}" != "${EXPECTED_OUTPUT}" ]]; then		echo "ERROR: Wrong output for arbitrary argument execution: ${out}"		return 1	fi} exec_interactive() {	exec_stdin_pipe "$@"	exec_argument "$@"} ktap_test() {	ktap_test_result "$*" "$@"} ktap_print_headerktap_set_plan 28 # Without secbit configuration, nothing is changed. ktap_print_msg "By default, executable scripts are allowed to be interpreted and executed."ktap_test exec_direct 0 script-exec.incktap_test exec_indirect 0 script-exec.inc ktap_print_msg "By default, executable stdin is allowed to be interpreted."ktap_test exec_stdin_reg 0 script-exec.inc ktap_print_msg "By default, non-executable scripts are allowed to be interpreted, but not directly executed."# We get 126 because of direct execution by Bash.ktap_test exec_direct 126 script-noexec.incktap_test exec_indirect 0 script-noexec.inc ktap_print_msg "By default, non-executable stdin is allowed to be interpreted."ktap_test exec_stdin_reg 0 script-noexec.inc ktap_print_msg "By default, interactive commands are allowed to be interpreted."ktap_test exec_interactive 0 # With only file restriction: protect non-malicious users from inadvertent errors (e.g. python ~/Downloads/*.py). ktap_print_msg "With -f, executable scripts are allowed to be interpreted and executed."ktap_test exec_direct 0 script-exec.inc ./set-exec -f --ktap_test exec_indirect 0 script-exec.inc ./set-exec -f -- ktap_print_msg "With -f, executable stdin is allowed to be interpreted."ktap_test exec_stdin_reg 0 script-exec.inc ./set-exec -f -- ktap_print_msg "With -f, non-executable scripts are not allowed to be executed nor interpreted."# Direct execution of non-executable script is alwayse denied by the kernel.ktap_test exec_direct 1 script-noexec.inc ./set-exec -f --ktap_test exec_indirect 1 script-noexec.inc ./set-exec -f -- ktap_print_msg "With -f, non-executable stdin is allowed to be interpreted."ktap_test exec_stdin_reg 0 script-noexec.inc ./set-exec -f -- ktap_print_msg "With -f, interactive commands are allowed to be interpreted."ktap_test exec_interactive 0 ./set-exec -f -- # With only denied interactive commands: check or monitor script content (e.g. with LSM). ktap_print_msg "With -i, executable scripts are allowed to be interpreted and executed."ktap_test exec_direct 0 script-exec.inc ./set-exec -i --ktap_test exec_indirect 0 script-exec.inc ./set-exec -i -- ktap_print_msg "With -i, executable stdin is allowed to be interpreted."ktap_test exec_stdin_reg 0 script-exec.inc ./set-exec -i -- ktap_print_msg "With -i, non-executable scripts are allowed to be interpreted, but not directly executed."# Direct execution of non-executable script is alwayse denied by the kernel.ktap_test exec_direct 1 script-noexec.inc ./set-exec -i --ktap_test exec_indirect 0 script-noexec.inc ./set-exec -i -- ktap_print_msg "With -i, non-executable stdin is not allowed to be interpreted."ktap_test exec_stdin_reg 1 script-noexec.inc ./set-exec -i -- ktap_print_msg "With -i, interactive commands are not allowed to be interpreted."ktap_test exec_interactive 1 ./set-exec -i -- # With both file restriction and denied interactive commands: only allow executable scripts. ktap_print_msg "With -fi, executable scripts are allowed to be interpreted and executed."ktap_test exec_direct 0 script-exec.inc ./set-exec -fi --ktap_test exec_indirect 0 script-exec.inc ./set-exec -fi -- ktap_print_msg "With -fi, executable stdin is allowed to be interpreted."ktap_test exec_stdin_reg 0 script-exec.inc ./set-exec -fi -- ktap_print_msg "With -fi, non-executable scripts are not allowed to be interpreted nor executed."# Direct execution of non-executable script is alwayse denied by the kernel.ktap_test exec_direct 1 script-noexec.inc ./set-exec -fi --ktap_test exec_indirect 1 script-noexec.inc ./set-exec -fi -- ktap_print_msg "With -fi, non-executable stdin is not allowed to be interpreted."ktap_test exec_stdin_reg 1 script-noexec.inc ./set-exec -fi -- ktap_print_msg "With -fi, interactive commands are not allowed to be interpreted."ktap_test exec_interactive 1 ./set-exec -fi -- ktap_finished