From patchwork Thu Mar 2 18:05:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13157719 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16EE8C678D4 for ; Thu, 2 Mar 2023 18:05:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229884AbjCBSFi (ORCPT ); Thu, 2 Mar 2023 13:05:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229642AbjCBSFh (ORCPT ); Thu, 2 Mar 2023 13:05:37 -0500 Received: from frasgout13.his.huawei.com (frasgout13.his.huawei.com [14.137.139.46]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C69425BAB for ; Thu, 2 Mar 2023 10:05:34 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.227]) by frasgout13.his.huawei.com (SkyGuard) with ESMTP id 4PSJhP0kpKz9xFGG for ; Fri, 3 Mar 2023 01:56:53 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwBnMVhY5QBk8KdkAQ--.10486S2; Thu, 02 Mar 2023 19:05:19 +0100 (CET) From: Roberto Sassu To: zohar@linux.ibm.com, dmitry.kasatkin@gmail.com Cc: linux-integrity@vger.kernel.org, vt@altlinux.org, pvorel@suse.cz, stefanb@linux.ibm.com, Roberto Sassu Subject: [PATCH ima-evm-utils v7] Add tests for MMAP_CHECK and MMAP_CHECK_REQPROT hooks Date: Thu, 2 Mar 2023 19:05:02 +0100 Message-Id: <20230302180502.618368-1-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: GxC2BwBnMVhY5QBk8KdkAQ--.10486S2 X-Coremail-Antispam: 1UD129KBjvAXoWftw45Xr48tr1DtrW3CF4kWFg_yoW8Zw15Jo WIgFZIv3WIyw1fA3s8uF4kCa4UGa4kCan8Ar1a9w45GF1vqryfC3WkAw1ftFWakr4rWrWq kF97X3WrZFWDJry3n29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7v73VFW2AGmfu7bjvjm3 AaLaJ3UjIYCTnIWjp_UUU5p7kC6x804xWl14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK 8VAvwI8IcIk0rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4 AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF 7I0E14v26r1j6r4UM28EF7xvwVC2z280aVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv6xkF7I 0E14v26r4j6r4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCj c4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4 CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1x MIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Wr1j6r W3Jr1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUv cSsGvfC2KfnxnUUI43ZEXa7IU1zuWJUUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQAEBF1jj4ojSQAAsQ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Roberto Sassu Add tests to ensure that, after applying the kernel patch 'ima: Align ima_file_mmap() parameters with mmap_file LSM hook', the MMAP_CHECK hook checks the protections applied by the kernel and not those requested by the application. Also ensure that after applying 'ima: Introduce MMAP_CHECK_REQPROT hook', the MMAP_CHECK_REQPROT hook checks the protections requested by the application. Test both with the test_mmap application that by default requests the PROT_READ protection flag. Its syntax is: test_mmap where mode can be: - exec: adds the PROT_EXEC protection flag to mmap() - read_implies_exec: calls the personality() system call with READ_IMPLIES_EXEC as the first argument before mmap() - mprotect: adds the PROT_EXEC protection flag to a memory area in addition to PROT_READ - exec_on_writable: calls mmap() with PROT_EXEC on a file which has a writable mapping Check the different combinations of hooks/modes and ensure that a measurement entry is found in the IMA measurement list only when it is expected. No measurement entry should be found when only the PROT_READ protection flag is requested or the matching policy rule has the MMAP_CHECK_REQPROT hook and the personality() system call was called with READ_IMPLIES_EXEC. mprotect() with PROT_EXEC on an existing memory area protected with PROT_READ should be denied (with an appraisal rule), regardless of the MMAP hook specified in the policy. The same applies for mmap() with PROT_EXEC on a file with a writable mapping. Signed-off-by: Roberto Sassu --- Changelog v6: - Make ret_* variables in upper case (suggested by Mimi) - Initialize variables always with hex values, and with a different style var=$((value)) (suggested by Mimi) v5: - Use the new awk script ima_policy_check.awk to check for policy overlap - Replace exit "$FAIL" with exit 1 when changing directory at the beginning of the script, as FAIL is not yet defined - Add fsmagic=0xef53 to the policy rules, to avoid overlap with the default ima_tcb policy (there is still overlap with the mmap rule) - Add colors to the test results - Replace i_version with iversion in the mount options - Require EVM disabled or HMAC mode v4: - Use separate UIDs for fowner= in measure and appraise policies - Add error messages for unexpected failed mmap() (reported by Mimi) and mprotect() v3: - Check if there are IMA policy rules without fowner= and fsuuid=, and if yes, skip the tests due to possible interference (suggested by Mimi) - Fix style issues in tests/mmap_check.test v2: - Distinguish setup-related errors from test-related errors in test_mmap - Rename key_path and key_path_der variables to g_key_path and g_key_path_der (suggested by Stefan) - Write data to the test file in check_mmap() - Ensure that there are no setup-related errors from test_mmap in tests/mmap_check.test - Print the found entry in the IMA measurement list (suggested by Mimi) - Check for errors when writing the test file in check_deny() - Pass TST_KEY_PATH to the new environment - Add description to each test (suggested by Mimi) v1: - Declare PATCHES and uses new expect_pass_if() and expect_fail_if() (suggested by Stefan) - Replace $FAIL with $HARDFAIL when the error occurs in the setup phase of the test (to not make an expect_fail test successful for other reasons than the focus of the test) - Declare local variables in one line (suggested by Stefan) - Print the test being executed at the beginning, so that the message always appears also if an error occurs - Print the result of the tests in a separate line and separate the output of each test tests/Makefile.am | 5 +- tests/mmap_check.test | 407 ++++++++++++++++++++++++++++++++++++++++++ tests/test_mmap.c | 128 +++++++++++++ 3 files changed, 539 insertions(+), 1 deletion(-) create mode 100755 tests/mmap_check.test create mode 100644 tests/test_mmap.c diff --git a/tests/Makefile.am b/tests/Makefile.am index 9a7d8a1f989..03aa5b76088 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -2,7 +2,10 @@ check_SCRIPTS = TESTS = $(check_SCRIPTS) check_SCRIPTS += ima_hash.test sign_verify.test boot_aggregate.test \ - fsverity.test portable_signatures.test ima_policy_check.test + fsverity.test portable_signatures.test ima_policy_check.test \ + mmap_check.test + +check_PROGRAMS := test_mmap .PHONY: check_logs check_logs: diff --git a/tests/mmap_check.test b/tests/mmap_check.test new file mode 100755 index 00000000000..2dd34335dfc --- /dev/null +++ b/tests/mmap_check.test @@ -0,0 +1,407 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (C) 2022-2023 Roberto Sassu +# +# Check the behavior of MMAP_CHECK and MMAP_CHECK_REQPROT + +trap '_report_exit_and_cleanup _cleanup_env cleanup' SIGINT SIGTERM SIGSEGV EXIT + +PATCHES=( +'ima: Align ima_file_mmap() parameters with mmap_file LSM hook' +'ima: Introduce MMAP_CHECK_REQPROT hook' +) + +RET_INVALID_RULE=$((0x0001)) +RET_RULE_OVERLAP=$((0x0002)) +RET_SAME_RULE_EXISTS=$((0x0004)) + +EVM_INIT_HMAC=$((0x0001)) +EVM_INIT_X509=$((0x0002)) + +# Base VERBOSE on the environment variable, if set. +VERBOSE="${VERBOSE:-0}" + +# Errors defined in test_mmap +ERR_SETUP=1 +ERR_TEST=2 + +cd "$(dirname "$0")" || exit 1 +export PATH=$PWD/../src:$PWD:$PATH +export LD_LIBRARY_PATH=$LD_LIBRARY_PATH +. ./functions.sh +_require evmctl + +cleanup() { + if [ "$g_loop_mounted" = "1" ]; then + popd > /dev/null || exit "$FAIL" + umount "$g_mountpoint" + fi + + if [ -n "$g_dev" ]; then + losetup -d "$g_dev" + fi + + if [ -n "$g_image" ]; then + rm -f "$g_image" + fi + + if [ -n "$g_mountpoint" ]; then + rm -Rf "$g_mountpoint" + fi + + if [ -n "$g_key_path_der" ]; then + rm -f "$g_key_path_der" + fi +} + +# Use the fsuuid= IMA policy keyword to select only files created/used by the +# tests below. Also use fowner= to differentiate between files created/used by +# individual tests. +IMA_UUID="28b23254-9467-44c0-b6ba-34b12e85a26e" +MEASURE_MMAP_CHECK_FOWNER=2000 +MEASURE_MMAP_CHECK_REQPROT_FOWNER=2001 +MEASURE_MMAP_CHECK_RULE="measure func=MMAP_CHECK fsmagic=0xef53 fsuuid=$IMA_UUID fowner=$MEASURE_MMAP_CHECK_FOWNER" +MEASURE_MMAP_CHECK_REQPROT_RULE="measure func=MMAP_CHECK_REQPROT fsmagic=0xef53 fsuuid=$IMA_UUID fowner=$MEASURE_MMAP_CHECK_REQPROT_FOWNER" +APPRAISE_MMAP_CHECK_FOWNER=2002 +APPRAISE_MMAP_CHECK_REQPROT_FOWNER=2003 +APPRAISE_MMAP_CHECK_RULE="appraise func=MMAP_CHECK fsmagic=0xef53 fsuuid=$IMA_UUID fowner=$APPRAISE_MMAP_CHECK_FOWNER" +APPRAISE_MMAP_CHECK_REQPROT_RULE="appraise func=MMAP_CHECK_REQPROT fsmagic=0xef53 fsuuid=$IMA_UUID fowner=$APPRAISE_MMAP_CHECK_REQPROT_FOWNER" + +check_load_ima_rule() { + local result new_policy color + + echo -e "$1\n$(cat /sys/kernel/security/ima/policy)" | ima_policy_check.awk + result=$? + + if [ $((result & RET_INVALID_RULE)) -eq $RET_INVALID_RULE ]; then + echo "${RED}Invalid rule${NORM}" + return "$HARDFAIL" + fi + + if [ $((result & RET_RULE_OVERLAP)) -eq $RET_RULE_OVERLAP ]; then + color=${YELLOW} + if [ -n "$TST_ENV" ]; then + color=${RED} + fi + + echo "${color}Possible interference with existing IMA policy rule${NORM}" + if [ -n "$TST_ENV" ]; then + return "$HARDFAIL" + fi + fi + + if [ $((result & RET_SAME_RULE_EXISTS)) -eq $RET_SAME_RULE_EXISTS ]; then + return "$OK" + fi + + new_policy=$(mktemp -p "$g_mountpoint") + echo "$1" > "$new_policy" + echo "$new_policy" > /sys/kernel/security/ima/policy + result=$? + rm -f "$new_policy" + + if [ "$result" -ne 0 ]; then + echo "${RED}Failed to set IMA policy${NORM}" + return "$HARDFAIL" + fi + + return "$OK" +} + +check_mmap() { + local hook="$1" + local arg="$2" + local test_file fowner rule result test_file_entry + + echo -e "\nTest: ${FUNCNAME[0]} (hook=\"$hook\", test_mmap arg: \"$arg\")" + + if ! test_file=$(mktemp -p "$PWD"); then + echo "${RED}Cannot create $test_file${NORM}" + return "$HARDFAIL" + fi + + if ! echo "test" > "$test_file"; then + echo "${RED}Cannot write $test_file${NORM}" + return "$FAIL" + fi + + fowner="$MEASURE_MMAP_CHECK_FOWNER" + rule="$MEASURE_MMAP_CHECK_RULE" + + if [ "$hook" = "MMAP_CHECK_REQPROT" ]; then + fowner="$MEASURE_MMAP_CHECK_REQPROT_FOWNER" + rule="$MEASURE_MMAP_CHECK_REQPROT_RULE" + fi + + if ! chown "$fowner" "$test_file"; then + echo "${RED}Cannot change owner of $test_file${NORM}" + return "$HARDFAIL" + fi + + check_load_ima_rule "$rule" + result=$? + if [ $result -ne "$OK" ]; then + return $result + fi + + test_mmap "$test_file" "$arg" + result=$? + + if [ $result -ne 0 ] && [ $result -ne "$ERR_TEST" ]; then + echo "${RED}Unexpected exit status $result from test_mmap${NORM}" + return "$HARDFAIL" + fi + + if [ "$TFAIL" != "yes" ]; then + echo -n "Result (expect found): " + else + echo -n "Result (expect not found): " + fi + + test_file_entry=$(awk '$5 == "'"$test_file"'"' < /sys/kernel/security/ima/ascii_runtime_measurements) + if [ -z "$test_file_entry" ]; then + if [ "$TFAIL" != "yes" ]; then + echo "${RED}not found${NORM}" + else + echo "${GREEN}not found${NORM}" + fi + return "$FAIL" + fi + + if [ "$TFAIL" != "yes" ]; then + echo "${GREEN}found${NORM}" + else + echo "${RED}found${NORM}" + fi + + if [ "$VERBOSE" -gt 0 ]; then + echo "$test_file_entry" + fi + + return "$OK" +} + +check_deny() { + local hook="$1" + local arg="$2" + local test_file fowner rule result + + echo -e "\nTest: ${FUNCNAME[0]} (hook=\"$hook\", test_mmap arg: \"$arg\")" + + if ! test_file=$(mktemp -p "$PWD"); then + echo "${RED}Cannot create $test_file${NORM}" + return "$HARDFAIL" + fi + + if ! echo "test" > "$test_file"; then + echo "${RED}Cannot write $test_file${NORM}" + return "$FAIL" + fi + + if ! evmctl ima_sign -a sha256 --key "$g_key_path" "$test_file" &> /dev/null; then + echo "${RED}Cannot sign $test_file${NORM}" + return "$HARDFAIL" + fi + + fowner="$APPRAISE_MMAP_CHECK_FOWNER" + rule="$APPRAISE_MMAP_CHECK_RULE" + + if [ "$hook" = "MMAP_CHECK_REQPROT" ]; then + fowner="$APPRAISE_MMAP_CHECK_REQPROT_FOWNER" + rule="$APPRAISE_MMAP_CHECK_REQPROT_RULE" + fi + + if ! chown "$fowner" "$test_file"; then + echo "${RED}Cannot change owner of $test_file${NORM}" + return "$HARDFAIL" + fi + + check_load_ima_rule "$rule" + result=$? + if [ $result -ne "$OK" ]; then + return $result + fi + + test_mmap "$test_file" exec + result=$? + + if [ $result -ne 0 ] && [ $result -ne "$ERR_TEST" ]; then + echo "${RED}Unexpected exit status $result from test_mmap${NORM}" + return "$HARDFAIL" + fi + + test_mmap "$test_file" "$arg" + result=$? + + if [ $result -ne 0 ] && [ $result -ne "$ERR_TEST" ]; then + echo "${RED}Unexpected exit status $result from test_mmap${NORM}" + return "$HARDFAIL" + fi + + if [ "$TFAIL" != "yes" ]; then + echo -n "Result (expect denied): " + else + echo -n "Result (expect allowed): " + fi + + if [ $result -eq 0 ]; then + if [ "$TFAIL" != "yes" ]; then + echo "${RED}allowed${NORM}" + else + echo "${GREEN}allowed${NORM}" + fi + return "$FAIL" + fi + + if [ "$TFAIL" != "yes" ]; then + echo "${GREEN}denied${NORM}" + else + echo "${RED}denied${NORM}" + fi + + return "$OK" +} + +# Run in the new environment if TST_ENV is set. +_run_env "$TST_KERNEL" "$PWD/$(basename "$0")" "TST_ENV=$TST_ENV TST_KERNEL=$TST_KERNEL PATH=$PATH LD_LIBRARY_PATH=$LD_LIBRARY_PATH VERBOSE=$VERBOSE TST_KEY_PATH=$TST_KEY_PATH" + +# Exit from the creator of the new environment. +_exit_env "$TST_KERNEL" + +# Mount filesystems in the new environment. +_init_env + +if [ "$(whoami)" != "root" ]; then + echo "${CYAN}This script must be executed as root${NORM}" + exit "$SKIP" +fi + +if [ ! -f /sys/kernel/security/ima/policy ]; then + echo "${CYAN}IMA policy file not found${NORM}" + exit "$SKIP" +fi + +if ! cat /sys/kernel/security/ima/policy &> /dev/null; then + echo "${CYAN}IMA policy file is not readable${NORM}" + exit "$SKIP" +fi + +if [ -n "$TST_KEY_PATH" ]; then + if [ "${TST_KEY_PATH:0:1}" != "/" ]; then + echo "${RED}Absolute path required for the signing key${NORM}" + exit "$FAIL" + fi + + if [ ! -f "$TST_KEY_PATH" ]; then + echo "${RED}Kernel signing key not found in $TST_KEY_PATH${NORM}" + exit "$FAIL" + fi + + g_key_path="$TST_KEY_PATH" +elif [ -f "$PWD/../signing_key.pem" ]; then + g_key_path="$PWD/../signing_key.pem" +elif [ -f "/lib/modules/$(uname -r)/source/certs/signing_key.pem" ]; then + g_key_path="/lib/modules/$(uname -r)/source/certs/signing_key.pem" +elif [ -f "/lib/modules/$(uname -r)/build/certs/signing_key.pem" ]; then + g_key_path="/lib/modules/$(uname -r)/build/certs/signing_key.pem" +else + echo "${CYAN}Kernel signing key not found${NORM}" + exit "$SKIP" +fi + +evm_value=$(cat /sys/kernel/security/evm) +if [ $((evm_value & EVM_INIT_X509)) -eq "$EVM_INIT_X509" ]; then + if [ $((evm_value & EVM_INIT_HMAC)) -ne "$EVM_INIT_HMAC" ]; then + echo "${CYAN}Incompatible EVM mode $evm_value${NORM}" + exit "$SKIP" + fi +fi + +g_key_path_der=$(mktemp) + +openssl x509 -in "$g_key_path" -out "$g_key_path_der" -outform der +if ! keyctl padd asymmetric pubkey %keyring:.ima < "$g_key_path_der" &> /dev/null; then + echo "${RED}Public key cannot be added to the IMA keyring${NORM}" + exit "$FAIL" +fi + +g_mountpoint=$(mktemp -d) +g_image=$(mktemp) + +if [ -z "$g_mountpoint" ]; then + echo "${RED}Mountpoint directory not created${NORM}" + exit "$FAIL" +fi + +if ! dd if=/dev/zero of="$g_image" bs=1M count=20 &> /dev/null; then + echo "${RED}Cannot create test image${NORM}" + exit "$FAIL" +fi + +g_dev=$(losetup -f "$g_image" --show) +if [ -z "$g_dev" ]; then + echo "${RED}Cannot create loop device${NORM}" + exit "$FAIL" +fi + +if ! mkfs.ext4 -U "$IMA_UUID" -b 4096 "$g_dev" &> /dev/null; then + echo "${RED}Cannot format $g_dev${NORM}" + exit "$FAIL" +fi + +if ! mount -o iversion "$g_dev" "$g_mountpoint"; then + echo "${RED}Cannot mount loop device${NORM}" + exit "$FAIL" +fi + +g_loop_mounted=1 +pushd "$g_mountpoint" > /dev/null || exit "$FAIL" + +# Ensure that IMA does not add a new measurement entry if an application calls +# mmap() with PROT_READ, and a policy rule contains the MMAP_CHECK hook. +# In this case, both the protections requested by the application and the final +# protections applied by the kernel contain only PROT_READ, so there is no +# match with the IMA rule, which expects PROT_EXEC to be set. +expect_fail check_mmap "MMAP_CHECK" "" + +# Ensure that IMA adds a new measurement entry if an application calls mmap() +# with PROT_READ | PROT_EXEC, and a policy rule contains the MMAP_CHECK hook. +expect_pass check_mmap "MMAP_CHECK" "exec" + +# Same as in the first test, but in this case the application calls the +# personality() system call with READ_IMPLIES_EXEC, which causes the kernel to +# add PROT_EXEC in the final protections passed to the MMAP_CHECK hook. +# +# Ensure that the bug introduced by 98de59bfe4b2 ("take calculation of final +# protections in security_mmap_file() into a helper") is fixed, by passing the +# final protections again to the MMAP_CHECK hook. Due to the bug, the hook +# received the protections requested by the application. Since those protections +# don't have PROT_EXEC, IMA was not creating a measurement entry. +expect_pass_if '0' check_mmap "MMAP_CHECK" "read_implies_exec" + +# Repeat the previous three tests, but with the new MMAP_CHECK_REQPROT hook, +# which behaves like the buggy MMAP_CHECK hook. In the third test, expect that +# no new measurement entry is created, since the MMAP_CHECK_REQPROT hook sees +# the protections requested by the application (PROT_READ). +expect_fail_if '1' check_mmap "MMAP_CHECK_REQPROT" "" +expect_pass_if '1' check_mmap "MMAP_CHECK_REQPROT" "exec" +expect_fail_if '1' check_mmap "MMAP_CHECK_REQPROT" "read_implies_exec" + +# Ensure that IMA refuses an mprotect() with PROT_EXEC on a memory area +# obtained with an mmap() with PROT_READ. This is due to the inability of IMA +# to measure/appraise the file for which mmap() was called (locking issue). +expect_pass check_deny "MMAP_CHECK" "mprotect" + +# Ensure that MMAP_CHECK_REQPROT has the same behavior of MMAP_CHECK for the +# previous test. +expect_pass_if '1' check_deny "MMAP_CHECK_REQPROT" "mprotect" + +# Ensure that there cannot be an mmap() with PROT_EXEC on a file with writable +# mappings, due to the inability of IMA to make a reliable measurement of that +# file. +expect_pass check_deny "MMAP_CHECK" "exec_on_writable" + +# Ensure that MMAP_CHECK_REQPROT has the same behavior of MMAP_CHECK for the +# previous test. +expect_pass_if '1' check_deny "MMAP_CHECK_REQPROT" "exec_on_writable" diff --git a/tests/test_mmap.c b/tests/test_mmap.c new file mode 100644 index 00000000000..63e7597f29a --- /dev/null +++ b/tests/test_mmap.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 Huawei Technologies Duesseldorf GmbH + * + * Tool to test IMA MMAP_CHECK and MMAP_CHECK_REQPROT hooks. + */ +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Convention: return 1 for errors that should not occur, as they are + * setup-related, return 2 for errors that might occur due to testing + * conditions. + */ +#define ERR_SETUP 1 +#define ERR_TEST 2 + +int main(int argc, char *argv[]) +{ + struct stat st; + void *ptr, *ptr_write = NULL; + int ret, fd, fd_write, prot = PROT_READ; + + if (!argv[1]) { + printf("Missing file parameter\n"); + return ERR_SETUP; + } + + if (argv[2] && !strcmp(argv[2], "read_implies_exec")) { + ret = personality(READ_IMPLIES_EXEC); + if (ret == -1) { + printf("Failed to set personality, err: %d (%s)\n", + -errno, strerror(errno)); + return ERR_SETUP; + } + } + + if (stat(argv[1], &st) == -1) { + printf("Failed to access %s, err: %d (%s)\n", argv[1], -errno, + strerror(errno)); + return ERR_SETUP; + } + + if (argv[2] && !strcmp(argv[2], "exec_on_writable")) { + fd_write = open(argv[1], O_RDWR); + if (fd_write == -1) { + printf("Failed to open %s in r/w, err: %d (%s)\n", + argv[1], -errno, strerror(errno)); + return ERR_SETUP; + } + + ptr_write = mmap(0, st.st_size, PROT_WRITE, MAP_SHARED, + fd_write, 0); + close(fd_write); + + if (ptr_write == MAP_FAILED) { + printf("Failed mmap() with PROT_WRITE on %s, err: %d (%s)\n", + argv[1], -errno, strerror(errno)); + return ERR_SETUP; + } + } + + fd = open(argv[1], O_RDONLY); + if (fd == -1) { + printf("Failed to open %s in ro, err: %d (%s)\n", argv[1], + -errno, strerror(errno)); + + if (ptr_write && munmap(ptr_write, st.st_size) == -1) + printf("Failed munmap() of writable mapping on %s, err: %d (%s)\n", + argv[1], -errno, strerror(errno)); + + return ERR_SETUP; + } + + if (argv[2] && !strncmp(argv[2], "exec", 4)) + prot |= PROT_EXEC; + + ptr = mmap(0, st.st_size, prot, MAP_PRIVATE, fd, 0); + + close(fd); + + if (ptr_write && munmap(ptr_write, st.st_size) == -1) { + printf("Failed munmap() of writable mapping on %s, err: %d (%s)\n", + argv[1], -errno, strerror(errno)); + return ERR_SETUP; + } + + if (ptr == MAP_FAILED) { + ret = ERR_SETUP; + if (argv[2] && !strcmp(argv[2], "exec_on_writable") && + errno == EACCES) + ret = ERR_TEST; + else + printf("Failed mmap() with PROT_READ%s on %s, err: %d (%s)\n", + (prot & PROT_EXEC) ? " | PROT_EXEC" : "", + argv[1], -errno, strerror(errno)); + + return ret; + } + + ret = 0; + + if (argv[2] && !strcmp(argv[2], "mprotect")) { + ret = mprotect(ptr, st.st_size, PROT_EXEC); + if (ret == -1) { + ret = ERR_SETUP; + if (errno == EPERM) + ret = ERR_TEST; + else + printf("Unexpected mprotect() error on %s, err: %d (%s)\n", + argv[1], -errno, strerror(errno)); + } + } + + if (munmap(ptr, st.st_size) == -1) { + printf("Failed munmap() of mapping on %s, err: %d (%s)\n", + argv[1], -errno, strerror(errno)); + return ERR_SETUP; + } + + return ret; +}