From patchwork Thu Jul 9 10:12:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 11653983 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 6A0F3913 for ; Thu, 9 Jul 2020 10:12:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BAE52074B for ; Thu, 9 Jul 2020 10:12:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="coFPDVVu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726645AbgGIKMo (ORCPT ); Thu, 9 Jul 2020 06:12:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726140AbgGIKMo (ORCPT ); Thu, 9 Jul 2020 06:12:44 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 003DAC061A0B for ; Thu, 9 Jul 2020 03:12:43 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id a6so1732012wrm.4 for ; Thu, 09 Jul 2020 03:12:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=F6g7fDptGIzcY72zTri5KBvJJQVzV3/1jzTXQNV3HuM=; b=coFPDVVuvafd81nThgtSu0cQL7bq1mh93sEFCf+KGqyoIo5FBqkxkIUod13S1KaPLu uXLU67/XWgjX/Knt7+yNrZdrx90+sADqntqOb2FgqXvmg+UFOcdAkEHE7pZEaVwfCD6n TpydZ84o6TTExBrj92STaQRWNhRTmdKhfvhEs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=F6g7fDptGIzcY72zTri5KBvJJQVzV3/1jzTXQNV3HuM=; b=LDuWDrtw+KIyWTSxDUICN/5TVJ670lN4jmaIvTQipbjKjmwkYklrRfGumb1zcf1sIw 4zHFZnvbiwT73lbeByvCAh0EIrD20Ei4sH5gte4mUvQmsgMcJO96MK39/xA7WU1Tjvhr Z/cad3hBV3UmXjzD+n7I5iqVPCTSszkDbD3+nOBolQHsP5rPUBaR/aXUrhQLftmDkyqi YT/I6Xpzl6uKcHeQmq1iYZJo6pRODGkX0IRRfRQgECx5UcBZCGQF52k4uMbkOAV/7TOn lVowsdRas2uncBa7G7SpymkoXvIPm11qlMb4FLCE076leq0G3BthIj3S0jETmrw18IXg +XuA== X-Gm-Message-State: AOAM532iYSHGiWGiXEoVWWQVGLG+jCefGR3bq9pzMePTLFatEozKGI4t 4KsPlWRfgcSsCp3QPHyvvhKlIA== X-Google-Smtp-Source: ABdhPJztxd9ybzuPdUmBiF9b0n0gq1IqMMvtclokdmjAg/DXj6rkBJNamKoGI+PesauLp51wDgEtRg== X-Received: by 2002:adf:e546:: with SMTP id z6mr58343987wrm.99.1594289562595; Thu, 09 Jul 2020 03:12:42 -0700 (PDT) Received: from kpsingh.zrh.corp.google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id g3sm5538287wrb.59.2020.07.09.03.12.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2020 03:12:42 -0700 (PDT) From: KP Singh To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Paul Turner , Jann Horn , Florent Revest Subject: [PATCH bpf-next v4 0/4] Generalizing bpf_local_storage Date: Thu, 9 Jul 2020 12:12:35 +0200 Message-Id: <20200709101239.3829793-1-kpsingh@chromium.org> X-Mailer: git-send-email 2.27.0.389.gc38d7665816-goog MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: KP Singh # v3 -> v4 - Fixed a missing include to bpf_sk_storage.h in bpf_sk_storage.c - Fixed some functions that were not marked as static which led to W=1 compilation warnings. # v2 -> v3 * Restructured the code as per Martin's suggestions: - Common functionality in bpf_local_storage.c - bpf_sk_storage functionality remains in net/bpf_sk_storage. - bpf_inode_storage is kept separate as it is enabled only with CONFIG_BPF_LSM. * A separate cache for inode and sk storage with macros to define it. * Use the ops style approach as suggested by Martin instead of the enum + switch style. * Added the inode map to bpftool bash completion and docs. * Rebase and indentation fixes. # v1 -> v2 * Use the security blob pointer instead of dedicated member in struct inode. * Better code re-use as suggested by Alexei. * Dropped the inode count arithmetic as pointed out by Alexei. * Minor bug fixes and rebase. bpf_sk_storage can already be used by some BPF program types to annotate socket objects. These annotations are managed with the life-cycle of the object (i.e. freed when the object is freed) which makes BPF programs much simpler and less prone to errors and leaks. This patch series: * Generalizes the bpf_sk_storage infrastructure to allow easy implementation of local storage for other objects * Implements local storage for inodes * Makes both bpf_{sk, inode}_storage available to LSM programs. Local storage is safe to use in LSM programs as the attachment sites are limited and the owning object won't be freed, however, this is not the case for tracing. Usage in tracing is expected to follow a white-list based approach similar to the d_path helper (https://lore.kernel.org/bpf/20200506132946.2164578-1-jolsa@kernel.org). Access to local storage would allow LSM programs to implement stateful detections like detecting the unlink of a running executable from the examples shared as a part of the KRSI series https://lore.kernel.org/bpf/20200329004356.27286-1-kpsingh@chromium.org/ and https://github.com/sinkap/linux-krsi/blob/patch/v1/examples/samples/bpf/lsm_detect_exec_unlink.c KP Singh (4): bpf: Generalize bpf_sk_storage bpf: Implement bpf_local_storage for inodes bpf: Allow local storage to be used from LSM programs bpf: Add selftests for local_storage include/linux/bpf.h | 14 + include/linux/bpf_local_storage.h | 190 ++++ include/linux/bpf_lsm.h | 21 + include/linux/bpf_types.h | 3 + include/net/bpf_sk_storage.h | 2 + include/net/sock.h | 4 +- include/uapi/linux/bpf.h | 54 +- kernel/bpf/Makefile | 2 + kernel/bpf/bpf_inode_storage.c | 333 +++++++ kernel/bpf/bpf_local_storage.c | 517 +++++++++++ kernel/bpf/bpf_lsm.c | 21 +- kernel/bpf/syscall.c | 3 +- kernel/bpf/verifier.c | 10 + net/core/bpf_sk_storage.c | 825 ++++-------------- security/bpf/hooks.c | 7 + .../bpf/bpftool/Documentation/bpftool-map.rst | 2 +- tools/bpf/bpftool/bash-completion/bpftool | 3 +- tools/bpf/bpftool/map.c | 3 +- tools/include/uapi/linux/bpf.h | 54 +- tools/lib/bpf/libbpf_probes.c | 5 +- .../bpf/prog_tests/test_local_storage.c | 60 ++ .../selftests/bpf/progs/local_storage.c | 136 +++ 22 files changed, 1599 insertions(+), 670 deletions(-) create mode 100644 include/linux/bpf_local_storage.h create mode 100644 kernel/bpf/bpf_inode_storage.c create mode 100644 kernel/bpf/bpf_local_storage.c create mode 100644 tools/testing/selftests/bpf/prog_tests/test_local_storage.c create mode 100644 tools/testing/selftests/bpf/progs/local_storage.c