From patchwork Tue Jan 30 00:06:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 13536580 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 39B7819F for ; Tue, 30 Jan 2024 00:07:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706573226; cv=none; b=hnQpN0KJyEFIzdIELX/b+1SAOIdi+/vFKLZ9mBFfoUXhB3r/IoZVaprq9VuQKUSX65vYpCPsUv0Eog+Ls3Lk7yXHAXdK0jrXgRIBXaKq31OuwCa2zpwUjYRmHbP2zT7fCuerjKP0aYYq8NAvVvxaz16nkIPUUvC88injHoMHiEc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706573226; c=relaxed/simple; bh=leqLz9LggKMc15rPYistVky65en8YWvALqOzf9Rv6r4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TUJ9ZtFGADXWwl/HI+F83hdPqQ8fvxkXhZcjopNp6HloMJUGjDi38wi1YBuMBSYi06/wz6l571twAOAjygRalXQLqOMYI7JMcwRrKCEw9TpOtdf/jaa7ES5R+ZXKFkAJebJ0CiX5uFJRDsX0IrvU6qYlNW+ObQp6yGAq5968/2Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=chxwHecr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="chxwHecr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2485C433C7; Tue, 30 Jan 2024 00:07:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706573225; bh=leqLz9LggKMc15rPYistVky65en8YWvALqOzf9Rv6r4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=chxwHecrI+Z1JpOKswoMfljvgUn0oHYvP5haO9Ks0jlD8SKsuXYC4W6v969fjRaUD p31oZ/9fmR5YT90iWNiJV1d/w8E4DurdeKJZUfv8A1FydFhFb8ysrjUpsNx1bF5roO 0M4kEX8kPc6RmVpSHS+09iO62MJENckMK3gQqZlzk16n0Y00Zjqn9n7yYgttOlyEDN dGSMe3ePDBvPK4V6Y9MD4hfvdWODFM1VaKtHNjo+tcivLSusJYHgmLQ0P4AflqJV3v XRW3LXfZHOG/N1FSKYJFad8bYDA1laSSZMe7SXU/8OI1Glx2Agj8mBUjmokkQDRqES pyPbchZ96K7CA== From: Andrii Nakryiko To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, martin.lau@kernel.org Cc: andrii@kernel.org, kernel-team@meta.com, Eduard Zingerman Subject: [PATCH v3 bpf-next 4/4] selftests/bpf: add trusted global subprog arg tests Date: Mon, 29 Jan 2024 16:06:48 -0800 Message-Id: <20240130000648.2144827-5-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240130000648.2144827-1-andrii@kernel.org> References: <20240130000648.2144827-1-andrii@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net Add a bunch of test cases validating behavior of __arg_trusted and its combination with __arg_nullable tag. We also validate CO-RE flavor support by kernel for __arg_trusted args. Acked-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko --- .../selftests/bpf/prog_tests/verifier.c | 2 + .../bpf/progs/verifier_global_ptr_args.c | 156 ++++++++++++++++++ 2 files changed, 158 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c index d62c5bf00e71..9c6072a19745 100644 --- a/tools/testing/selftests/bpf/prog_tests/verifier.c +++ b/tools/testing/selftests/bpf/prog_tests/verifier.c @@ -28,6 +28,7 @@ #include "verifier_div0.skel.h" #include "verifier_div_overflow.skel.h" #include "verifier_global_subprogs.skel.h" +#include "verifier_global_ptr_args.skel.h" #include "verifier_gotol.skel.h" #include "verifier_helper_access_var_len.skel.h" #include "verifier_helper_packet_access.skel.h" @@ -140,6 +141,7 @@ void test_verifier_direct_stack_access_wraparound(void) { RUN(verifier_direct_st void test_verifier_div0(void) { RUN(verifier_div0); } void test_verifier_div_overflow(void) { RUN(verifier_div_overflow); } void test_verifier_global_subprogs(void) { RUN(verifier_global_subprogs); } +void test_verifier_global_ptr_args(void) { RUN(verifier_global_ptr_args); } void test_verifier_gotol(void) { RUN(verifier_gotol); } void test_verifier_helper_access_var_len(void) { RUN(verifier_helper_access_var_len); } void test_verifier_helper_packet_access(void) { RUN(verifier_helper_packet_access); } diff --git a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c new file mode 100644 index 000000000000..484d6262363f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c @@ -0,0 +1,156 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include +#include +#include "bpf_misc.h" +#include "xdp_metadata.h" +#include "bpf_kfuncs.h" + +extern struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak; +extern void bpf_task_release(struct task_struct *p) __ksym __weak; + +__weak int subprog_trusted_task_nullable(struct task_struct *task __arg_trusted __arg_nullable) +{ + if (!task) + return 0; + return task->pid + task->tgid; +} + +SEC("?kprobe") +__success __log_level(2) +__msg("Validating subprog_trusted_task_nullable() func#1...") +__msg(": R1=trusted_ptr_or_null_task_struct(") +int trusted_task_arg_nullable(void *ctx) +{ + struct task_struct *t = bpf_get_current_task_btf(); + + return subprog_trusted_task_nullable(t) + subprog_trusted_task_nullable(NULL); +} + +__weak int subprog_trusted_task_nonnull(struct task_struct *task __arg_trusted) +{ + return task->pid + task->tgid; +} + +SEC("?kprobe") +__failure __log_level(2) +__msg("R1 type=scalar expected=ptr_, trusted_ptr_, rcu_ptr_") +__msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')") +int trusted_task_arg_nonnull_fail1(void *ctx) +{ + return subprog_trusted_task_nonnull(NULL); +} + +SEC("?tp_btf/task_newtask") +__failure __log_level(2) +__msg("R1 type=ptr_or_null_ expected=ptr_, trusted_ptr_, rcu_ptr_") +__msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')") +int trusted_task_arg_nonnull_fail2(void *ctx) +{ + struct task_struct *t = bpf_get_current_task_btf(); + struct task_struct *nullable; + int res; + + nullable = bpf_task_acquire(t); + + /* should fail, PTR_TO_BTF_ID_OR_NULL */ + res = subprog_trusted_task_nonnull(nullable); + + if (nullable) + bpf_task_release(nullable); + + return res; +} + +SEC("?kprobe") +__success __log_level(2) +__msg("Validating subprog_trusted_task_nonnull() func#1...") +__msg(": R1=trusted_ptr_task_struct(") +int trusted_task_arg_nonnull(void *ctx) +{ + struct task_struct *t = bpf_get_current_task_btf(); + + return subprog_trusted_task_nonnull(t); +} + +struct task_struct___local {} __attribute__((preserve_access_index)); + +__weak int subprog_nullable_task_flavor( + struct task_struct___local *task __arg_trusted __arg_nullable) +{ + char buf[16]; + + if (!task) + return 0; + + return bpf_copy_from_user_task(&buf, sizeof(buf), NULL, (void *)task, 0); +} + +SEC("?uprobe.s") +__success __log_level(2) +__msg("Validating subprog_nullable_task_flavor() func#1...") +__msg(": R1=trusted_ptr_or_null_task_struct(") +int flavor_ptr_nullable(void *ctx) +{ + struct task_struct___local *t = (void *)bpf_get_current_task_btf(); + + return subprog_nullable_task_flavor(t); +} + +__weak int subprog_nonnull_task_flavor(struct task_struct___local *task __arg_trusted) +{ + char buf[16]; + + return bpf_copy_from_user_task(&buf, sizeof(buf), NULL, (void *)task, 0); +} + +SEC("?uprobe.s") +__success __log_level(2) +__msg("Validating subprog_nonnull_task_flavor() func#1...") +__msg(": R1=trusted_ptr_task_struct(") +int flavor_ptr_nonnull(void *ctx) +{ + struct task_struct *t = bpf_get_current_task_btf(); + + return subprog_nonnull_task_flavor((void *)t); +} + +__weak int subprog_trusted_destroy(struct task_struct *task __arg_trusted) +{ + bpf_task_release(task); /* should be rejected */ + + return 0; +} + +SEC("?tp_btf/task_newtask") +__failure __log_level(2) +__msg("release kernel function bpf_task_release expects refcounted PTR_TO_BTF_ID") +int BPF_PROG(trusted_destroy_fail, struct task_struct *task, u64 clone_flags) +{ + return subprog_trusted_destroy(task); +} + +__weak int subprog_trusted_acq_rel(struct task_struct *task __arg_trusted) +{ + struct task_struct *owned; + + owned = bpf_task_acquire(task); + if (!owned) + return 0; + + bpf_task_release(owned); /* this one is OK, we acquired it locally */ + + return 0; +} + +SEC("?tp_btf/task_newtask") +__success __log_level(2) +int BPF_PROG(trusted_acq_rel, struct task_struct *task, u64 clone_flags) +{ + return subprog_trusted_acq_rel(task); +} + +char _license[] SEC("license") = "GPL";