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: 10777065 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 E3C0391E for ; Wed, 23 Jan 2019 11:04:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D4B1C288E4 for ; Wed, 23 Jan 2019 11:04:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C8BF32BD2E; 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 77C32288E4 for ; Wed, 23 Jan 2019 11:04:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727464AbfAWLEh (ORCPT ); Wed, 23 Jan 2019 06:04:37 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:44411 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727589AbfAWLEP (ORCPT ); Wed, 23 Jan 2019 06:04:15 -0500 Received: by mail-pl1-f193.google.com with SMTP id e11so998472plt.11 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=dFlqnW/UVKXPC5GaYojrO/iL/kYkfQzJzVjgsMeSpk78mqj8SrDPkk82lBFg0TIPlo VbN7ffK6qmObV6JwTxw7g9jXN7Xjtmtqtfdx/yFNp1Ix9V057Iih8c0phS6XHZRKDg1c O7qxkCcGEANrBWN2Ce3QHUgY8j224R/Pg7X+XB+nptMlUu2ydJvex9eEVEma9Ov+vsRv C8XOblOUVe823P/j6/GWC6NVzDrXp6qCEZN316w0N2FV3uXJ4s7/Mj3y6hn8FqyGDqhp xW5NRzq2u+MCI+sust0v3tbPLL5L67sF+9Q6C/hrKE/kHMhJohwSeJXvHA3xg+d9CmEf Ki9g== X-Gm-Message-State: AJcUukdXylXHYJUdy7dQL6+OAbl+e8LIKwJbjgzxNeosoW8RtNJLjbXd 4+d+0xT6OhSEe0ZFCvYkwt+xTg== 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-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@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