From patchwork Tue Sep 29 12:45:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 11805763 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 15707112C for ; Tue, 29 Sep 2020 12:46:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E05E82145D for ; Tue, 29 Sep 2020 12:46:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iOwHuFqu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387461AbgI2MqV (ORCPT ); Tue, 29 Sep 2020 08:46:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33075 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387419AbgI2MqG (ORCPT ); Tue, 29 Sep 2020 08:46:06 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601383564; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+g4gavvzkE9a6aqv0X291vvrq93unWSXrCpz4oNLKB8=; b=iOwHuFquA4001/R0rEDuogHArlpaoIRx9bsS5KaLUvo6Hg1iKcAd+hKDCg+jysjos1gmyL vrXlAf5C3uHaJ8Fllcx0iD0ZzAy1ajIL4AG7Cg62LvFb4DndV+GenmCimgYCJppQ3upjzu NqJOkzjDcuzRE98KaBvc6mm2ymN8Uiw= Received: from mail-oi1-f199.google.com (mail-oi1-f199.google.com [209.85.167.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-517-lA_v0_U9O_-K8iGDLUwIWA-1; Tue, 29 Sep 2020 08:46:02 -0400 X-MC-Unique: lA_v0_U9O_-K8iGDLUwIWA-1 Received: by mail-oi1-f199.google.com with SMTP id j13so1562283oij.11 for ; Tue, 29 Sep 2020 05:46:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=+g4gavvzkE9a6aqv0X291vvrq93unWSXrCpz4oNLKB8=; b=n3ANAwBfr3k2P3X6mTFe1B/anEN6HLd15emaABD1j9mm9m7VF4tU72B2FN7Q+43XPU bvri8U6+0xiFtAWwJTBXThUjRJIGwzJFM74Ayxix9OQe1118expkZHQ8rWgBoAr/9f+I EOf3h2r8sKWhttRJQsGznuqpCu6YvkRH9uxGo2y+xlPN12q+PzC1VuGcu1ZjpjTX1NGB sIe+gS6y5EM/I/Xm2vCHor+nJQWKE8rozUIE3omJxoqstwafYjskr7GP+wKk0esliL20 djDhSR6ySB3K0C/KFTs+s8qQlpD8ZUMdhp+ppwJDfNKdTuVNYlfDGrL79oT2hgWkEH3D Xt0w== X-Gm-Message-State: AOAM532YBCq0XcoaDoK36i5uM5nGspc+eImaxH+siLZpRY6nPPSeo1xP GEXRkSH8IwpzZd4GrpCc5v7ll0IRAeNundLTV9zsiJXuRM1fMZxBXY5rpi9wT9GX1l6k9l1UIWi +MjGEg8NuQWFz X-Received: by 2002:a05:6830:150a:: with SMTP id k10mr2490491otp.167.1601383560678; Tue, 29 Sep 2020 05:46:00 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyhZ6bbqG0rcTTHpIecObb0KcP+Dmz9DesXltkItA3D2L762yo+YRChxD3SAPCXz7ANYjPgKg== X-Received: by 2002:a05:6830:150a:: with SMTP id k10mr2490476otp.167.1601383560453; Tue, 29 Sep 2020 05:46:00 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id a2sm2871165ooo.26.2020.09.29.05.45.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Sep 2020 05:45:58 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 37FF2183C5F; Tue, 29 Sep 2020 14:45:57 +0200 (CEST) Subject: [PATCH bpf-next v10 7/7] selftests: Add selftest for disallowing modify_return attachment to freplace From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Alexei Starovoitov Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , Jiri Olsa , Eelco Chaudron , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org Date: Tue, 29 Sep 2020 14:45:57 +0200 Message-ID: <160138355713.48470.3811074984255709369.stgit@toke.dk> In-Reply-To: <160138354947.48470.11523413403103182788.stgit@toke.dk> References: <160138354947.48470.11523413403103182788.stgit@toke.dk> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Toke Høiland-Jørgensen This adds a selftest that ensures that modify_return tracing programs cannot be attached to freplace programs. The security_ prefix is added to the freplace program because that would otherwise let it pass the check for modify_return. Acked-by: Andrii Nakryiko Signed-off-by: Toke Høiland-Jørgensen --- .../selftests/bpf/prog_tests/fexit_bpf2bpf.c | 56 ++++++++++++++++++++ .../selftests/bpf/progs/fmod_ret_freplace.c | 14 +++++ .../selftests/bpf/progs/freplace_get_constant.c | 2 - 3 files changed, 71 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/progs/fmod_ret_freplace.c diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c index 2b94e827b2c5..5c0448910426 100644 --- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c +++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c @@ -232,6 +232,60 @@ static void test_func_replace_multi(void) prog_name, true, test_second_attach); } +static void test_fmod_ret_freplace(void) +{ + struct bpf_object *freplace_obj = NULL, *pkt_obj, *fmod_obj = NULL; + const char *freplace_name = "./freplace_get_constant.o"; + const char *fmod_ret_name = "./fmod_ret_freplace.o"; + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts); + const char *tgt_name = "./test_pkt_access.o"; + struct bpf_link *freplace_link = NULL; + struct bpf_program *prog; + __u32 duration = 0; + int err, pkt_fd; + + err = bpf_prog_load(tgt_name, BPF_PROG_TYPE_UNSPEC, + &pkt_obj, &pkt_fd); + /* the target prog should load fine */ + if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n", + tgt_name, err, errno)) + return; + opts.attach_prog_fd = pkt_fd; + + freplace_obj = bpf_object__open_file(freplace_name, &opts); + if (CHECK(IS_ERR_OR_NULL(freplace_obj), "freplace_obj_open", + "failed to open %s: %ld\n", freplace_name, + PTR_ERR(freplace_obj))) + goto out; + + err = bpf_object__load(freplace_obj); + if (CHECK(err, "freplace_obj_load", "err %d\n", err)) + goto out; + + prog = bpf_program__next(NULL, freplace_obj); + freplace_link = bpf_program__attach_trace(prog); + if (CHECK(IS_ERR(freplace_link), "freplace_attach_trace", "failed to link\n")) + goto out; + + opts.attach_prog_fd = bpf_program__fd(prog); + fmod_obj = bpf_object__open_file(fmod_ret_name, &opts); + if (CHECK(IS_ERR_OR_NULL(fmod_obj), "fmod_obj_open", + "failed to open %s: %ld\n", fmod_ret_name, + PTR_ERR(fmod_obj))) + goto out; + + err = bpf_object__load(fmod_obj); + if (CHECK(!err, "fmod_obj_load", "loading fmod_ret should fail\n")) + goto out; + +out: + bpf_link__destroy(freplace_link); + bpf_object__close(freplace_obj); + bpf_object__close(fmod_obj); + bpf_object__close(pkt_obj); +} + + static void test_func_sockmap_update(void) { const char *prog_name[] = { @@ -314,4 +368,6 @@ void test_fexit_bpf2bpf(void) test_func_map_prog_compatibility(); if (test__start_subtest("func_replace_multi")) test_func_replace_multi(); + if (test__start_subtest("fmod_ret_freplace")) + test_fmod_ret_freplace(); } diff --git a/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c b/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c new file mode 100644 index 000000000000..c8943ccee6c0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +volatile __u64 test_fmod_ret = 0; +SEC("fmod_ret/security_new_get_constant") +int BPF_PROG(fmod_ret_test, long val, int ret) +{ + test_fmod_ret = 1; + return 120; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/freplace_get_constant.c b/tools/testing/selftests/bpf/progs/freplace_get_constant.c index 8f0ecf94e533..705e4b64dfc2 100644 --- a/tools/testing/selftests/bpf/progs/freplace_get_constant.c +++ b/tools/testing/selftests/bpf/progs/freplace_get_constant.c @@ -5,7 +5,7 @@ volatile __u64 test_get_constant = 0; SEC("freplace/get_constant") -int new_get_constant(long val) +int security_new_get_constant(long val) { if (val != 123) return 0;