From patchwork Wed Jan 23 11:03:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10777067 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 11A69139A for ; Wed, 23 Jan 2019 11:04:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0343A288E4 for ; Wed, 23 Jan 2019 11:04:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EA98F2BCF6; Wed, 23 Jan 2019 11:04:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 992C92AC03 for ; Wed, 23 Jan 2019 11:04:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727498AbfAWLEh (ORCPT ); Wed, 23 Jan 2019 06:04:37 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:43797 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727579AbfAWLEP (ORCPT ); Wed, 23 Jan 2019 06:04:15 -0500 Received: by mail-pl1-f193.google.com with SMTP id gn14so997356plb.10 for ; Wed, 23 Jan 2019 03:04:15 -0800 (PST) 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=eOH0evUuoYnXDQzpGOjj3b0HOCtKjXfnS8BAvgmzoB0=; b=Wr6sF2dnqShAFPTeXkP0pt6mBKUJKO97OmiEruwT4K55nJajA+h03gbSSobjz2XPfv dmHCD/XalktgqQ0IiUYMC5jVtzQxKJiJoguJ4OOCavlkG9DFAMd11Miq++jy+d12pAW9 urv3sOXBGTMXSshhkP6/iBRMUbWJT7/wXVNA4= 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=eOH0evUuoYnXDQzpGOjj3b0HOCtKjXfnS8BAvgmzoB0=; b=drCvDcn4NGZnC+jl23FdVnLkvWH4JSB4JUj0SHFhrlehRa5y78txQO6E2SDY402V77 DU+0xpg9mCbyPXuAZo/9aA3IjiVfxQRXu9Jb/gjtSMf6mVnZKdsYe0LBjUFu2Oe5k/kd HAkrcnERO+0SvewS1ih916Ud1FnO562RMJXa1iRKtijpRqge1OVQQ19y6O5HA/2mpb3N pv6IJToZsDqy87z39qezahwmhMXb/joTtV1ssZ6fPYhlqaIM34dd3fU7m2bmAYpX6vOw hHLxYayUly+MLB6D8VVis9Lf6XrxLSKJu1y/gNxPlvGopwdj++tS+U2d1Sx7qU46B4no 41Gw== X-Gm-Message-State: AJcUukcUyM4OhjvzGR4nMgkW+sz6QbBOo+jXGpYbsXsW+hQiJq7WAJHe 35STqFcalaEkzWTxc8BfOT1u2w== X-Google-Smtp-Source: ALg8bN4MaWR5XqsDsgdWgLwpfKZxt4LUG4ZZGKgogh3VDQfDjkiUg54eL3BLTvjTOGXKhvj7c+hNuQ== X-Received: by 2002:a17:902:714c:: with SMTP id u12mr1770044plm.234.1548241455187; Wed, 23 Jan 2019 03:04:15 -0800 (PST) Received: from www.outflux.net (173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133]) by smtp.gmail.com with ESMTPSA id n186sm23207263pfn.137.2019.01.23.03.04.12 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 23 Jan 2019 03:04:12 -0800 (PST) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Ard Biesheuvel , Laura Abbott , Alexander Popov , xen-devel@lists.xenproject.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, dev@openvswitch.org, linux-kbuild@vger.kernel.org, linux-security-module@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: [PATCH 0/3] gcc-plugins: Introduce stackinit plugin Date: Wed, 23 Jan 2019 03:03:46 -0800 Message-Id: <20190123110349.35882-1-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This adds a new plugin "stackinit" that attempts to perform unconditional initialization of all stack variables[1]. It has wider effects than GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y since BYREF_ALL does not consider non-structures. A notable weakness is that padding bytes in many cases remain uninitialized since GCC treats these bytes as "undefined". I'm hoping we can improve the compiler (or the plugin) to cover that too. (It's worth noting that BYREF_ALL actually does handle the padding -- I think this is due to the different method of detecting if initialization is needed.) Included is a tree-wide change to move switch variables up and out of their switch and into the top-level variable declarations. Included is a set of test cases for evaluating stack initialization, which checks for padding, different types, etc. Feedback welcome! :) -Kees [1] https://lkml.kernel.org/r/CA+55aFykZL+cSBJjBBts7ebEFfyGPdMzTmLSxKnT_29=j942dA@mail.gmail.com Kees Cook (3): treewide: Lift switch variables out of switches gcc-plugins: Introduce stackinit plugin lib: Introduce test_stackinit module arch/x86/xen/enlighten_pv.c | 7 +- drivers/char/pcmcia/cm4000_cs.c | 2 +- drivers/char/ppdev.c | 20 +- drivers/gpu/drm/drm_edid.c | 4 +- drivers/gpu/drm/i915/intel_display.c | 2 +- drivers/gpu/drm/i915/intel_pm.c | 4 +- drivers/net/ethernet/intel/e1000/e1000_main.c | 3 +- drivers/tty/n_tty.c | 3 +- drivers/usb/gadget/udc/net2280.c | 5 +- fs/fcntl.c | 3 +- lib/Kconfig.debug | 9 + lib/Makefile | 1 + lib/test_stackinit.c | 327 ++++++++++++++++++ mm/shmem.c | 5 +- net/core/skbuff.c | 4 +- net/ipv6/ip6_gre.c | 4 +- net/ipv6/ip6_tunnel.c | 4 +- net/openvswitch/flow_netlink.c | 7 +- scripts/Makefile.gcc-plugins | 6 + scripts/gcc-plugins/Kconfig | 9 + scripts/gcc-plugins/gcc-common.h | 11 +- scripts/gcc-plugins/stackinit_plugin.c | 79 +++++ security/tomoyo/common.c | 3 +- security/tomoyo/condition.c | 7 +- security/tomoyo/util.c | 4 +- 25 files changed, 484 insertions(+), 49 deletions(-) create mode 100644 lib/test_stackinit.c create mode 100644 scripts/gcc-plugins/stackinit_plugin.c