From patchwork Sat Sep 19 11:49:54 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: 1367560 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=hPgDz2py; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Btpst3QgGz9sTC for ; Sat, 19 Sep 2020 21:50:10 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726461AbgISLuF (ORCPT ); Sat, 19 Sep 2020 07:50:05 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:29340 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726400AbgISLuB (ORCPT ); Sat, 19 Sep 2020 07:50:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600516198; 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=hPgDz2pyoVrfz2ows2uk9+c7x0NIrespsxXz5YR46cGecbzU0ZmSYPWxW942VVNoD7/OGB b6B7f7OyFyxOdV3Q2A0AJ2IqcTUfdhQT0AZuFI1FYfX0x8IK3evnutBfxEbaWnCnNjrhFv ddXuAXZ+IVFDbTL6CMo4YbEplYQwpHM= Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-299-1S3kOP7RM-GBM1t67bnsYg-1; Sat, 19 Sep 2020 07:49:57 -0400 X-MC-Unique: 1S3kOP7RM-GBM1t67bnsYg-1 Received: by mail-ej1-f70.google.com with SMTP id dc22so3121249ejb.21 for ; Sat, 19 Sep 2020 04:49:56 -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=Gc/P7DLhw2NfVt6q3bLubBwXvZiTacfg/6L9LwB0P7ynXRa8jnTFZerloGHuRglzET ftgPvug7pIoqVj5T/Z2Koj0oNZxXxpe+74wQukg/maTbYs+Aa3RDxFYSY8/hzH5KUGI8 OjMyWwD5yVTbRdQOVBt1eGI6SM6yyVL4l6AyRtaFiuJQVwnOOsmmRj/Y6PgRQ9C6XGYf gozS0hEswmURpKEfDDg09l8SWlYuJ590InCxjrqzvSMLZF/y9ObcK+X/HtSCvGzk0CsC K6MGdbOVA8YlCTZAYZKNr+gBzo04TXBmDF7GEExSmZ4xOb/9VLAG7UmyEkGoQ1BiWdvo ICqw== X-Gm-Message-State: AOAM531TmZPE5lMlzmikeYXhZ57FEI81IFDTGcha1Pop3WaSNha3S58k w642dpNCEuApD0KLoNlYHslXPAnLgLPS/lhlEfBg2rfQ0KdNKyu1i2dga0AVLpzfAU6bK+jMOub dI0FA7KfTJf3KTvt8 X-Received: by 2002:a17:906:7248:: with SMTP id n8mr40167571ejk.160.1600516195311; Sat, 19 Sep 2020 04:49:55 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwET4wLasS4GyN4HhrrhJC65BBFerQhuAVWgNzLqhJ7YH2ZyMXgBmViYW56KvvkEBeUQAEFFQ== X-Received: by 2002:a17:906:7248:: with SMTP id n8mr40167551ejk.160.1600516194925; Sat, 19 Sep 2020 04:49:54 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id z23sm4271334eja.29.2020.09.19.04.49.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Sep 2020 04:49:54 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 0E336183A98; Sat, 19 Sep 2020 13:49:54 +0200 (CEST) Subject: [PATCH bpf-next v7 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: Sat, 19 Sep 2020 13:49:54 +0200 Message-ID: <160051619397.58048.16822043567956571063.stgit@toke.dk> In-Reply-To: <160051618267.58048.2336966160671014012.stgit@toke.dk> References: <160051618267.58048.2336966160671014012.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 Acked-by: Andrii Nakryiko --- .../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;