From patchwork Wed Aug 31 16:54:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12961115 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 40E8CECAAD4 for ; Wed, 31 Aug 2022 16:59:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232404AbiHaQ7U (ORCPT ); Wed, 31 Aug 2022 12:59:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232454AbiHaQ6m (ORCPT ); Wed, 31 Aug 2022 12:58:42 -0400 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AE03DB07E; Wed, 31 Aug 2022 09:58:05 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.229]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4MHqwg2fsnz9xHvF; Thu, 1 Sep 2022 00:52:35 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwBX0lxfkg9jJXIRAA--.5993S14; Wed, 31 Aug 2022 17:57:35 +0100 (CET) From: Roberto Sassu To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, mykolal@fb.com, dhowells@redhat.com, jarkko@kernel.org, rostedt@goodmis.org, mingo@redhat.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, shuah@kernel.org Cc: bpf@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, deso@posteo.net, memxor@gmail.com, Roberto Sassu Subject: [PATCH v15 12/12] selftests/bpf: Add tests for dynamic pointers parameters in kfuncs Date: Wed, 31 Aug 2022 18:54:45 +0200 Message-Id: <20220831165445.1071641-13-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220831165445.1071641-1-roberto.sassu@huaweicloud.com> References: <20220831165445.1071641-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwBX0lxfkg9jJXIRAA--.5993S14 X-Coremail-Antispam: 1UD129KBjvJXoW3Ar1rtr1fWFW8GF48WFW5trb_yoW7uw1xpa 1rGryj9r40q3W3Wr13JF4xur4fKr4kZw17CrZIv34xZr1DXrWrXF18KFW5J3Z8K395Xw45 Z3ySqFWruw48Ja7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBIb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6r1S6rWUM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVWxJr0_GcWl84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAF wI0_Cr1j6rxdM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2 Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s02 6x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0x vE2Ix0cI8IcVAFwI0_Xr0_Ar1lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4UJVW0owCI42IY 6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aV CY1x0267AKxVWxJr0_GcJvcSsGvfC2KfnxnUUI43ZEXa7IUbGXdUUUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgABBF1jj357FgADsm X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Roberto Sassu Add tests to ensure that only supported dynamic pointer types are accepted, that the passed argument is actually a dynamic pointer, and that the passed argument is a pointer to the stack. Signed-off-by: Roberto Sassu --- .../bpf/prog_tests/kfunc_dynptr_param.c | 102 ++++++++++++++++++ .../bpf/progs/test_kfunc_dynptr_param.c | 57 ++++++++++ 2 files changed, 159 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c create mode 100644 tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c new file mode 100644 index 000000000000..732897faf36b --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2022 Facebook + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + */ + +#include +#include "test_kfunc_dynptr_param.skel.h" + +static size_t log_buf_sz = 1048576; /* 1 MB */ +static char obj_log_buf[1048576]; + +static struct { + const char *prog_name; + const char *expected_err_msg; +} kfunc_dynptr_tests[] = { + {"dynptr_type_not_supp", + "arg#0 pointer type STRUCT bpf_dynptr_kern points to unsupported dynamic pointer type"}, + {"not_valid_dynptr", + "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid and initialized"}, + {"not_ptr_to_stack", "arg#0 pointer type STRUCT bpf_dynptr_kern not to stack"}, +}; + +static bool kfunc_not_supported; + +static int libbpf_print_cb(enum libbpf_print_level level, const char *fmt, + va_list args) +{ + if (strcmp(fmt, "libbpf: extern (func ksym) '%s': not found in kernel or module BTFs\n")) + return 0; + + if (strcmp(va_arg(args, char *), "bpf_verify_pkcs7_signature")) + return 0; + + kfunc_not_supported = true; + return 0; +} + +static void verify_fail(const char *prog_name, const char *expected_err_msg) +{ + struct test_kfunc_dynptr_param *skel; + LIBBPF_OPTS(bpf_object_open_opts, opts); + libbpf_print_fn_t old_print_cb; + struct bpf_program *prog; + int err; + + opts.kernel_log_buf = obj_log_buf; + opts.kernel_log_size = log_buf_sz; + opts.kernel_log_level = 1; + + skel = test_kfunc_dynptr_param__open_opts(&opts); + if (!ASSERT_OK_PTR(skel, "test_kfunc_dynptr_param__open_opts")) + goto cleanup; + + prog = bpf_object__find_program_by_name(skel->obj, prog_name); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto cleanup; + + bpf_program__set_autoload(prog, true); + + bpf_map__set_max_entries(skel->maps.ringbuf, getpagesize()); + + kfunc_not_supported = false; + + old_print_cb = libbpf_set_print(libbpf_print_cb); + err = test_kfunc_dynptr_param__load(skel); + libbpf_set_print(old_print_cb); + + if (err < 0 && kfunc_not_supported) { + fprintf(stderr, + "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not supported\n", + __func__); + test__skip(); + goto cleanup; + } + + if (!ASSERT_ERR(err, "unexpected load success")) + goto cleanup; + + if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg), "expected_err_msg")) { + fprintf(stderr, "Expected err_msg: %s\n", expected_err_msg); + fprintf(stderr, "Verifier output: %s\n", obj_log_buf); + } + +cleanup: + test_kfunc_dynptr_param__destroy(skel); +} + +void test_kfunc_dynptr_param(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(kfunc_dynptr_tests); i++) { + if (!test__start_subtest(kfunc_dynptr_tests[i].prog_name)) + continue; + + verify_fail(kfunc_dynptr_tests[i].prog_name, + kfunc_dynptr_tests[i].expected_err_msg); + } +} diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c new file mode 100644 index 000000000000..2f09f91a1576 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + */ + +#include "vmlinux.h" +#include +#include +#include + +struct bpf_dynptr { + __u64 :64; + __u64 :64; +} __attribute__((aligned(8))); + +extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr, + struct bpf_dynptr *sig_ptr, + struct bpf_key *trusted_keyring) __ksym; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); +} ringbuf SEC(".maps"); + +char _license[] SEC("license") = "GPL"; + +SEC("?lsm.s/bpf") +int BPF_PROG(dynptr_type_not_supp, int cmd, union bpf_attr *attr, + unsigned int size) +{ + char write_data[64] = "hello there, world!!"; + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr); + + return bpf_verify_pkcs7_signature(&ptr, &ptr, NULL); +} + +SEC("?lsm.s/bpf") +int BPF_PROG(not_valid_dynptr, int cmd, union bpf_attr *attr, unsigned int size) +{ + unsigned long val; + + return bpf_verify_pkcs7_signature((struct bpf_dynptr *)&val, + (struct bpf_dynptr *)&val, NULL); +} + +SEC("?lsm.s/bpf") +int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr, unsigned int size) +{ + unsigned long val; + + return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val, + (struct bpf_dynptr *)val, NULL); +}