From patchwork Tue Jul 12 18:41:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12915425 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 14174C43334 for ; Tue, 12 Jul 2022 18:47:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234462AbiGLSrw (ORCPT ); Tue, 12 Jul 2022 14:47:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234337AbiGLSrZ (ORCPT ); Tue, 12 Jul 2022 14:47:25 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A368D914B; Tue, 12 Jul 2022 11:43:14 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Lj8gm616hz67PZF; Wed, 13 Jul 2022 02:40:04 +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 15.1.2375.24; Tue, 12 Jul 2022 20:43:05 +0200 From: Roberto Sassu To: , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v7 5/7] selftests: Add verifier tests for bpf_lookup_user_key() and bpf_key_put() Date: Tue, 12 Jul 2022 20:41:26 +0200 Message-ID: <20220712184128.999301-6-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220712184128.999301-1-roberto.sassu@huawei.com> References: <20220712184128.999301-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml754-chm.china.huawei.com (10.201.108.204) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add verifier tests for bpf_lookup_user_key() and bpf_key_put(), to ensure that acquired key references can be released, that a non-NULL pointer is passed to bpf_key_put(), and that key references are not leaked. Also, slightly modify test_verifier.c, to find the BTF ID of the attach point for the LSM program type (currently, it is done only for TRACING). Signed-off-by: Roberto Sassu --- tools/testing/selftests/bpf/test_verifier.c | 3 +- .../selftests/bpf/verifier/ref_tracking.c | 66 +++++++++++++++++++ 2 files changed, 68 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index f9d553fbf68a..2dbcbf363c18 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -1498,7 +1498,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv, opts.log_level = DEFAULT_LIBBPF_LOG_LEVEL; opts.prog_flags = pflags; - if (prog_type == BPF_PROG_TYPE_TRACING && test->kfunc) { + if ((prog_type == BPF_PROG_TYPE_TRACING || + prog_type == BPF_PROG_TYPE_LSM) && test->kfunc) { int attach_btf_id; attach_btf_id = libbpf_find_vmlinux_btf_id(test->kfunc, diff --git a/tools/testing/selftests/bpf/verifier/ref_tracking.c b/tools/testing/selftests/bpf/verifier/ref_tracking.c index 57a83d763ec1..36e0b9b342de 100644 --- a/tools/testing/selftests/bpf/verifier/ref_tracking.c +++ b/tools/testing/selftests/bpf/verifier/ref_tracking.c @@ -84,6 +84,72 @@ .errstr = "Unreleased reference", .result = REJECT, }, +{ + "reference tracking: release key reference", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_EMIT_CALL(BPF_FUNC_lookup_user_key), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_EMIT_CALL(BPF_FUNC_key_put), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .result = ACCEPT, +}, +{ + "reference tracking: release key reference without check", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_EMIT_CALL(BPF_FUNC_lookup_user_key), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_EMIT_CALL(BPF_FUNC_key_put), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "type=ptr_or_null_ expected=ptr_", + .result = REJECT, +}, +{ + "reference tracking: release reference with NULL key pointer", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_key_put), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "type=scalar expected=ptr_", + .result = REJECT, +}, +{ + "reference tracking: leak potential reference to key", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_EMIT_CALL(BPF_FUNC_lookup_user_key), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "Unreleased reference", + .result = REJECT, +}, { "reference tracking: release reference without check", .insns = {