From patchwork Tue Feb 15 12:40:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12747048 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 C8D46C4167D for ; Tue, 15 Feb 2022 12:44:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237912AbiBOMoL (ORCPT ); Tue, 15 Feb 2022 07:44:11 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:56230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237969AbiBOMnm (ORCPT ); Tue, 15 Feb 2022 07:43:42 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F97F20F46; Tue, 15 Feb 2022 04:43:03 -0800 (PST) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4JygcY3VYqz67Ybb; Tue, 15 Feb 2022 20:38:37 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 15 Feb 2022 13:43:01 +0100 From: Roberto Sassu To: , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v2 6/6] selftests/bpf: Add test for bpf_lsm_kernel_read_file() Date: Tue, 15 Feb 2022 13:40:42 +0100 Message-ID: <20220215124042.186506-7-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220215124042.186506-1-roberto.sassu@huawei.com> References: <20220215124042.186506-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml753-chm.china.huawei.com (10.201.108.203) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Test the ability of bpf_lsm_kernel_read_file() to call the sleepable functions bpf_ima_inode_hash() or bpf_ima_file_hash() to obtain a measurement of a loaded IMA policy. Signed-off-by: Roberto Sassu --- tools/testing/selftests/bpf/ima_setup.sh | 2 ++ .../selftests/bpf/prog_tests/test_ima.c | 3 +- tools/testing/selftests/bpf/progs/ima.c | 28 ++++++++++++++++--- 3 files changed, 28 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/bpf/ima_setup.sh b/tools/testing/selftests/bpf/ima_setup.sh index 8e62581113a3..82530f19f85a 100755 --- a/tools/testing/selftests/bpf/ima_setup.sh +++ b/tools/testing/selftests/bpf/ima_setup.sh @@ -51,6 +51,7 @@ setup() ensure_mount_securityfs echo "measure func=BPRM_CHECK fsuuid=${mount_uuid}" > ${IMA_POLICY_FILE} + echo "measure func=BPRM_CHECK fsuuid=${mount_uuid}" > ${mount_dir}/policy_test } cleanup() { @@ -74,6 +75,7 @@ run() local mount_dir="${tmp_dir}/mnt" local copied_bin_path="${mount_dir}/$(basename ${TEST_BINARY})" + echo ${mount_dir}/policy_test > ${IMA_POLICY_FILE} exec "${copied_bin_path}" } diff --git a/tools/testing/selftests/bpf/prog_tests/test_ima.c b/tools/testing/selftests/bpf/prog_tests/test_ima.c index 62bf0e830453..c4a62d7b70df 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_ima.c +++ b/tools/testing/selftests/bpf/prog_tests/test_ima.c @@ -97,8 +97,9 @@ void test_test_ima(void) /* * 1 sample with use_ima_file_hash = false * 2 samples with use_ima_file_hash = true (./ima_setup.sh, /bin/true) + * 1 sample with use_ima_file_hash = true (IMA policy) */ - ASSERT_EQ(err, 3, "num_samples_or_err"); + ASSERT_EQ(err, 4, "num_samples_or_err"); ASSERT_NEQ(ima_hash_from_bpf, 0, "ima_hash"); close_clean: diff --git a/tools/testing/selftests/bpf/progs/ima.c b/tools/testing/selftests/bpf/progs/ima.c index 9bb63f96cfc0..9b4c03f30a1c 100644 --- a/tools/testing/selftests/bpf/progs/ima.c +++ b/tools/testing/selftests/bpf/progs/ima.c @@ -20,8 +20,7 @@ char _license[] SEC("license") = "GPL"; bool use_ima_file_hash; -SEC("lsm.s/bprm_committed_creds") -void BPF_PROG(ima, struct linux_binprm *bprm) +static void ima_test_common(struct file *file) { u64 ima_hash = 0; u64 *sample; @@ -31,10 +30,10 @@ void BPF_PROG(ima, struct linux_binprm *bprm) pid = bpf_get_current_pid_tgid() >> 32; if (pid == monitored_pid) { if (!use_ima_file_hash) - ret = bpf_ima_inode_hash(bprm->file->f_inode, &ima_hash, + ret = bpf_ima_inode_hash(file->f_inode, &ima_hash, sizeof(ima_hash)); else - ret = bpf_ima_file_hash(bprm->file, &ima_hash, + ret = bpf_ima_file_hash(file, &ima_hash, sizeof(ima_hash)); if (ret < 0 || ima_hash == 0) return; @@ -49,3 +48,24 @@ void BPF_PROG(ima, struct linux_binprm *bprm) return; } + +SEC("lsm.s/bprm_committed_creds") +void BPF_PROG(ima, struct linux_binprm *bprm) +{ + ima_test_common(bprm->file); +} + +SEC("lsm.s/kernel_read_file") +int BPF_PROG(kernel_read_file, struct file *file, enum kernel_read_file_id id, + bool contents) +{ + if (!contents) + return 0; + + if (id != READING_POLICY) + return 0; + + ima_test_common(file); + + return 0; +}