From patchwork Tue Oct 24 06:30:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 13433944 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 2AF111FA1; Tue, 24 Oct 2023 06:31:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UjGL0kXC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28E06C433C7; Tue, 24 Oct 2023 06:31:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698129064; bh=unyAYy3K9TAFCk6hTRrNH7bAJvS9PIbHMq1oMr5LqsQ=; h=From:To:Cc:Subject:Date:From; b=UjGL0kXCGc5SFQ4DBilcW1dQc20kyOIV7aO5MBwFf7hfOygHf2X7LyH3rvjhYspeL MFkdc/H4PqPtlln+OJ9gENqHQafR/hqBKy9SNaPwawxpWnuXUa7dTRylc7ZnWnDUq5 zX/tpi3dzoZkIuXWVwWtJN9egI+0dfGTiTJzSITvvIp1jdE1f5er3HOc3hqKC+7smJ nyGvztW9LML/oLA53YKaSmSfE8JmwEv+QnySgwSU7/bX37LKe5PH9S1+30NlbDK81F 79n+1f7ce4Rngm8yfTj1aUUV+Pqgg45r09kSQDGjrCUiCvDDpjl+mtzeMWm57jhgvl upax1ytFhRo+g== From: Song Liu To: bpf@vger.kernel.org, fsverity@lists.linux.dev Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, kernel-team@meta.com, ebiggers@kernel.org, tytso@mit.edu, roberto.sassu@huaweicloud.com, Song Liu Subject: [PATCH v5 bpf-next 0/9] bpf: File verification with LSM and fsverity Date: Mon, 23 Oct 2023 23:30:47 -0700 Message-Id: <20231024063056.1008702-1-song@kernel.org> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: fsverity@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Changes v4 => v5: 1. Revise commit logs. (Alexei) Changes v3 => v4: 1. Fix error reported by CI. 2. Update comments of bpf_dynptr_slice* that they may return error pointer. Changes v2 => v3: 1. Rebase and resolve conflicts. Changes v1 => v2: 1. Let bpf_get_file_xattr() use const string for arg "name". (Alexei) 2. Add recursion prevention with allowlist. (Alexei) 3. Let bpf_get_file_xattr() use __vfs_getxattr() to avoid recursion, as vfs_getxattr() calls into other LSM hooks. 4. Do not use dynptr->data directly, use helper insteadd. (Andrii) 5. Fixes with bpf_get_fsverity_digest. (Eric Biggers) 6. Add documentation. (Eric Biggers) 7. Fix some compile warnings. (kernel test robot) This set enables file verification with BPF LSM and fsverity. In this solution, fsverity is used to provide reliable and efficient hash of files; and BPF LSM is used to implement signature verification (against asymmetric keys), and to enforce access control. This solution can be used to implement access control in complicated cases. For example: only signed python binary and signed python script and access special files/devices/ports. Thanks, Song Song Liu (9): bpf: Expose bpf_dynptr_slice* kfuncs for in kernel use bpf: Factor out helper check_reg_const_str() bpf: Introduce KF_ARG_PTR_TO_CONST_STR bpf: Add kfunc bpf_get_file_xattr bpf, fsverity: Add kfunc bpf_get_fsverity_digest Documentation/bpf: Add documentation for filesystem kfuncs selftests/bpf: Sort config in alphabetic order selftests/bpf: Add tests for filesystem kfuncs selftests/bpf: Add test that uses fsverity and xattr to sign a file Documentation/bpf/fs_kfuncs.rst | 21 +++ Documentation/bpf/index.rst | 1 + Documentation/bpf/kfuncs.rst | 24 +++ fs/verity/fsverity_private.h | 10 ++ fs/verity/init.c | 1 + fs/verity/measure.c | 85 +++++++++ include/linux/bpf.h | 4 + kernel/bpf/helpers.c | 16 +- kernel/bpf/verifier.c | 104 +++++++---- kernel/trace/bpf_trace.c | 74 +++++++- tools/testing/selftests/bpf/bpf_kfuncs.h | 10 ++ tools/testing/selftests/bpf/config | 3 +- .../selftests/bpf/prog_tests/fs_kfuncs.c | 132 ++++++++++++++ .../bpf/prog_tests/verify_pkcs7_sig.c | 163 +++++++++++++++++- .../selftests/bpf/progs/test_fsverity.c | 46 +++++ .../selftests/bpf/progs/test_get_xattr.c | 37 ++++ .../selftests/bpf/progs/test_sig_in_xattr.c | 82 +++++++++ .../bpf/progs/test_verify_pkcs7_sig.c | 8 +- .../testing/selftests/bpf/verify_sig_setup.sh | 25 +++ 19 files changed, 789 insertions(+), 57 deletions(-) create mode 100644 Documentation/bpf/fs_kfuncs.rst create mode 100644 tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c create mode 100644 tools/testing/selftests/bpf/progs/test_fsverity.c create mode 100644 tools/testing/selftests/bpf/progs/test_get_xattr.c create mode 100644 tools/testing/selftests/bpf/progs/test_sig_in_xattr.c --- 2.34.1