From patchwork Thu Sep 17 20:20:11 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: 260698 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A74BC43463 for ; Thu, 17 Sep 2020 20:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12B742087D for ; Thu, 17 Sep 2020 20:20:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="a/W6Mhcc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726662AbgIQUU0 (ORCPT ); Thu, 17 Sep 2020 16:20:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38870 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726687AbgIQUUV (ORCPT ); Thu, 17 Sep 2020 16:20:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600374019; 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=utfMK0fpz+Di6YKgONWOEtGJeoQeNvRbM0wd8gaCZ8U=; b=a/W6MhccT92kYY+U6AxswV334O8AA0sD4pjJyQoWvSPwq7WAsYuiF2qcpdfNaeROrjLEd2 +nZhz9cr6TAvndQ52F5mhmDoClm0+k/XAeA5Qd8vDMuFvD/5luyX6pZNgVhWdo+o+dZDIO Tr0AfvT30/x/XQlfEJ81pOyI5sAszeE= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-149-zzDWq2BDPJevqnaNFU3Bng-1; Thu, 17 Sep 2020 16:20:16 -0400 X-MC-Unique: zzDWq2BDPJevqnaNFU3Bng-1 Received: by mail-ej1-f71.google.com with SMTP id dc22so1317110ejb.21 for ; Thu, 17 Sep 2020 13:20:16 -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=utfMK0fpz+Di6YKgONWOEtGJeoQeNvRbM0wd8gaCZ8U=; b=bgoOJMsrLqY5MKsYoWCZMo/I3DwYgCcqq6c7vpAR2S5Vylq/RKRT5dvdV/9p1IwmtL BwaI+9le1SVEiDYzYOBg2sZsvO0eyzjxbo+uLrNGr/Z2L3KLUU39za7TrDXw/BNjUePb TAvy40FIT3HaPDUGhrAorbCIZ3H070JpiCMrn61LeELNlp1m2bq3N2tB/QI368AtwUkz 01MmGAPt1qR+SGXRvoCpPV7xyBMlLkEQC4vyUF8Etud7U8ZYBEIxQo9j9nGG5czERfjO y/aYx2W6FqDofgUfwq+8nvPP+zMq5TfQfOdOZc0cNM0Gu2lZ2j75j1HL5WPorKIfPzih Ynqg== X-Gm-Message-State: AOAM532LEtZMuU/DcmSAlJBgqSWawKhhDCxvtENKI/KmlE2zE2ZK8fj1 N521qiqwpFYMqNEVqJ69dH3/9SN3Xiog80bjhykEHcGNVq0N0XkRqlgbYFBjh8q2nmoFv/FKySG b0OHh4pwqj5hR8YcD X-Received: by 2002:a50:9b44:: with SMTP id a4mr33993175edj.12.1600374014666; Thu, 17 Sep 2020 13:20:14 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxaciW8tG440uTdlNwDKJDmptZbQNSa+lRZbVQSmel/IQ38y98L4ha57CCv6RRiz52sXM2oLw== X-Received: by 2002:a50:9b44:: with SMTP id a4mr33993141edj.12.1600374014305; Thu, 17 Sep 2020 13:20:14 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id q12sm546410edj.19.2020.09.17.13.20.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2020 13:20:12 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 848E1183A91; Thu, 17 Sep 2020 22:20:11 +0200 (CEST) Subject: [PATCH bpf-next v6 10/10] 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: Thu, 17 Sep 2020 22:20:11 +0200 Message-ID: <160037401148.28970.15646899510538322830.stgit@toke.dk> In-Reply-To: <160037400056.28970.7647821897296177963.stgit@toke.dk> References: <160037400056.28970.7647821897296177963.stgit@toke.dk> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@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. Signed-off-by: Toke Høiland-Jørgensen --- .../selftests/bpf/prog_tests/fexit_bpf2bpf.c | 68 ++++++++++++++++++++ .../selftests/bpf/progs/fmod_ret_freplace.c | 14 ++++ .../selftests/bpf/progs/freplace_get_constant.c | 2 - 3 files changed, 83 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 27677e015730..6339d125ef9a 100644 --- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c +++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c @@ -233,6 +233,72 @@ static void test_func_replace_multi(void) prog_name, true, test_second_attach); } +static void test_fmod_ret_freplace(void) +{ + const char *tgt_name = "./test_pkt_access.o"; + const char *freplace_name = "./freplace_get_constant.o"; + const char *fmod_ret_name = "./fmod_ret_freplace.o"; + struct bpf_link *freplace_link = NULL, *fmod_link = NULL; + struct bpf_object *freplace_obj = NULL, *pkt_obj, *fmod_obj = 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; + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, 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", "err %d\n", err)) + goto out; + + prog = bpf_program__next(NULL, fmod_obj); + fmod_link = bpf_program__attach_trace(prog); + if (CHECK(!IS_ERR(fmod_link), "fmod_attach_trace", + "linking fmod_ret to freplace should fail\n")) + goto out; + +out: + if (!IS_ERR_OR_NULL(freplace_link)) + bpf_link__destroy(freplace_link); + if (!IS_ERR_OR_NULL(fmod_link)) + bpf_link__destroy(fmod_link); + if (!IS_ERR_OR_NULL(freplace_obj)) + bpf_object__close(freplace_obj); + if (!IS_ERR_OR_NULL(fmod_obj)) + bpf_object__close(fmod_obj); + bpf_object__close(pkt_obj); +} + + static void test_func_sockmap_update(void) { const char *prog_name[] = { @@ -315,4 +381,6 @@ 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;