From patchwork Fri Mar 8 13:27:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Potapenko X-Patchwork-Id: 10844735 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 C793E1575 for ; Fri, 8 Mar 2019 13:27:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B6DF22E105 for ; Fri, 8 Mar 2019 13:27:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AA80E2E2AF; Fri, 8 Mar 2019 13:27:19 +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=-14.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_HI,USER_IN_DEF_DKIM_WL autolearn=ham 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 9F4662E105 for ; Fri, 8 Mar 2019 13:27:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726613AbfCHN1O (ORCPT ); Fri, 8 Mar 2019 08:27:14 -0500 Received: from mail-qk1-f201.google.com ([209.85.222.201]:53032 "EHLO mail-qk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726420AbfCHN1N (ORCPT ); Fri, 8 Mar 2019 08:27:13 -0500 Received: by mail-qk1-f201.google.com with SMTP id k21so16026142qkg.19 for ; Fri, 08 Mar 2019 05:27:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=DonascqMy3PhwjdMFpXGWY3tn2Kfz58+pK6v9ziBCGw=; b=jIqy183CTzRolLba25ikaQxg70uR63YnyXBT+qJ2lmeFO/XVhfz2S2/oWoThosigy3 AgkHJzyZNWLIkQQRRi+sfudZCHNQd5QoPYWA8IBFJcatahUYkYMBDNs29NNId6bunJsl n/bnwr90jOSg/6Hwl+4QclCxH6PBJTpS9IifdglOWLLR3Ca3ytihBCkSWg1arNq9rW4c JtOfZ7PuOtDa/VHOVnZqIgjcw93t7pgwzgnHoywqrDxn9iaSILB3rtLni6hoOp9fjEZv u5zRQZf05HGjS5UKj3UpxE1jbFg4pFqNmiOIkY+MMMOHADNqUjSV9h+aR+iXPnzRrwl+ USgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=DonascqMy3PhwjdMFpXGWY3tn2Kfz58+pK6v9ziBCGw=; b=jkg8hmFvZxIPlZdgLaBMCSV6x7w2PENxIkJpS2qO8GST7zYVbckVOA1FUPwCu2D252 gKa/s1huoXooqFlcNMnrbMHH91YR93KPBk2IryTMbm1FYYHIJ4snoJ/Cfy15hdIpEaeq DL3f0YcaGK22Zg5CLjn31yHJ/8C9SCXP0e5sfGKhJTqWce5vlQmRX054S6h5sUaBIAB7 2AuxfxypTQPZafRfaP6hl0mkoMMoHCGahL8lBT1Z56p45GGLYRs3gnAQ4iiZzg0U4V0a 6mMUZVAY1Htj6gKXdkXkoymROY+EkFD+Hjn3ekeE8AXgH94uNlRBNmNRAm/oEoK/mqCC favw== X-Gm-Message-State: APjAAAVa/RIK0c9QWjV7V0ebUFl2Wr06+s0Nd08AQEAGJZ7zux6WwxG2 zgLTnncqCjuJbCbxqZK5pUu4UgVrato= X-Google-Smtp-Source: APXvYqwEXyIdROcbm/nFflhE0HQU8mXCHdw26Ax4EYsc5Rbf1PQmWaPmC6AEe98c9W1gbkP7LBrlBZeIydM= X-Received: by 2002:ac8:2539:: with SMTP id 54mr10029911qtm.45.1552051632222; Fri, 08 Mar 2019 05:27:12 -0800 (PST) Date: Fri, 8 Mar 2019 14:27:00 +0100 In-Reply-To: <20190308132701.133598-1-glider@google.com> Message-Id: <20190308132701.133598-2-glider@google.com> Mime-Version: 1.0 References: <20190308132701.133598-1-glider@google.com> X-Mailer: git-send-email 2.21.0.360.g471c308f928-goog Subject: [PATCH v2 1/2] initmem: introduce CONFIG_INIT_ALL_MEMORY and CONFIG_INIT_ALL_STACK From: Alexander Potapenko To: yamada.masahiro@socionext.com, jmorris@namei.org, serge@hallyn.com Cc: linux-security-module@vger.kernel.org, linux-kbuild@vger.kernel.org, ndesaulniers@google.com, kcc@google.com, dvyukov@google.com, keescook@chromium.org, sspatil@android.com, kernel-hardening@lists.openwall.com Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP CONFIG_INIT_ALL_MEMORY is going to be an umbrella config for options that force heap and stack initialization. The rationale behind doing so is to reduce the severity of bugs caused by using uninitialized memory. CONFIG_INIT_ALL_STACK turns on stack initialization based on -ftrivial-auto-var-init in Clang builds and on -fplugin-arg-structleak_plugin-byref-all in GCC builds. -ftrivial-auto-var-init is a Clang flag that provides trivial initializers for uninitialized local variables, variable fields and padding. It has three possible values: pattern - uninitialized locals are filled with a fixed pattern (mostly 0xAA on 64-bit platforms, see https://reviews.llvm.org/D54604 for more details) likely to cause crashes when uninitialized value is used; zero (it's still debated whether this flag makes it to the official Clang release) - uninitialized locals are filled with zeroes; uninitialized (default) - uninitialized locals are left intact. The proposed config builds the kernel with -ftrivial-auto-var-init=pattern. Developers have the possibility to opt-out of this feature on a per-file (by using the INIT_ALL_MEMORY_ Makefile prefix) or per-variable (by using __attribute__((uninitialized))) basis. For GCC builds, CONFIG_INIT_ALL_STACK is simply wired up to CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL. No opt-out is possible at the moment. Signed-off-by: Alexander Potapenko Cc: Masahiro Yamada Cc: James Morris Cc: "Serge E. Hallyn" Cc: Nick Desaulniers Cc: Kostya Serebryany Cc: Dmitry Vyukov Cc: Kees Cook Cc: Sandeep Patil Cc: linux-security-module@vger.kernel.org Cc: linux-kbuild@vger.kernel.org Cc: kernel-hardening@lists.openwall.com --- v2: - addressed Kees Cook's comments: added GCC support --- Makefile | 3 ++- scripts/Makefile.initmem | 10 ++++++++++ scripts/Makefile.lib | 6 ++++++ security/Kconfig | 1 + security/Kconfig.initmem | 29 +++++++++++++++++++++++++++++ 5 files changed, 48 insertions(+), 1 deletion(-) create mode 100644 scripts/Makefile.initmem create mode 100644 security/Kconfig.initmem diff --git a/Makefile b/Makefile index f070e0d65186..028ca37878fd 100644 --- a/Makefile +++ b/Makefile @@ -448,7 +448,7 @@ export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE -export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN +export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN CFLAGS_INITMEM export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL @@ -840,6 +840,7 @@ KBUILD_ARFLAGS := $(call ar-option,D) include scripts/Makefile.kasan include scripts/Makefile.extrawarn include scripts/Makefile.ubsan +include scripts/Makefile.initmem # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the # last assignments diff --git a/scripts/Makefile.initmem b/scripts/Makefile.initmem new file mode 100644 index 000000000000..a6253d78fe35 --- /dev/null +++ b/scripts/Makefile.initmem @@ -0,0 +1,10 @@ +ifdef CONFIG_INIT_ALL_STACK + +# Clang's -ftrivial-auto-var-init=pattern flag initializes the +# uninitialized parts of local variables (including fields and padding) +# with a fixed pattern (0xAA in most cases). +ifdef CONFIG_CC_HAS_AUTO_VAR_INIT + CFLAGS_INITMEM := -ftrivial-auto-var-init=pattern +endif + +endif diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 12b88d09c3a4..53d18fd15c79 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -131,6 +131,12 @@ _c_flags += $(if $(patsubst n%,, \ $(CFLAGS_UBSAN)) endif +ifeq ($(CONFIG_INIT_ALL_MEMORY),y) +_c_flags += $(if $(patsubst n%,, \ + $(INIT_ALL_MEMORY_$(basetarget).o)$(INIT_ALL_MEMORY)y), \ + $(CFLAGS_INITMEM)) +endif + ifeq ($(CONFIG_KCOV),y) _c_flags += $(if $(patsubst n%,, \ $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \ diff --git a/security/Kconfig b/security/Kconfig index e4fe2f3c2c65..cc12a39424dd 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -230,6 +230,7 @@ config STATIC_USERMODEHELPER_PATH If you wish for all usermode helper programs to be disabled, specify an empty string here (i.e. ""). +source "security/Kconfig.initmem" source "security/selinux/Kconfig" source "security/smack/Kconfig" source "security/tomoyo/Kconfig" diff --git a/security/Kconfig.initmem b/security/Kconfig.initmem new file mode 100644 index 000000000000..27aec394365e --- /dev/null +++ b/security/Kconfig.initmem @@ -0,0 +1,29 @@ +menu "Initialize all memory" + +config CC_HAS_AUTO_VAR_INIT + def_bool $(cc-option,-ftrivial-auto-var-init=pattern) + +config INIT_ALL_MEMORY + bool "Initialize all memory" + default n + help + Enforce memory initialization to mitigate infoleaks and make + the control-flow bugs depending on uninitialized values more + deterministic. + +if INIT_ALL_MEMORY + +config INIT_ALL_STACK + bool "Initialize all stack" + depends on INIT_ALL_MEMORY + depends on CC_HAS_AUTO_VAR_INIT || HAVE_GCC_PLUGINS + select GCC_PLUGINS if !CC_HAS_AUTO_VAR_INIT + select GCC_PLUGIN_STRUCTLEAK if !CC_HAS_AUTO_VAR_INIT + select GCC_PLUGIN_STRUCTLEAK_BYREF_ALL if !CC_HAS_AUTO_VAR_INIT + default y + help + Initialize uninitialized stack data with a fixed pattern + (0x00 in GCC, 0xAA in Clang). + +endif # INIT_ALL_MEMORY +endmenu From patchwork Fri Mar 8 13:27:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Potapenko X-Patchwork-Id: 10844733 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 82817139A for ; Fri, 8 Mar 2019 13:27:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 71C302E171 for ; Fri, 8 Mar 2019 13:27:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 65E112E2CE; Fri, 8 Mar 2019 13:27:18 +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=-14.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_HI,USER_IN_DEF_DKIM_WL autolearn=ham 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 A2C832E2AF for ; Fri, 8 Mar 2019 13:27:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726675AbfCHN1R (ORCPT ); Fri, 8 Mar 2019 08:27:17 -0500 Received: from mail-yw1-f73.google.com ([209.85.161.73]:46413 "EHLO mail-yw1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726420AbfCHN1R (ORCPT ); Fri, 8 Mar 2019 08:27:17 -0500 Received: by mail-yw1-f73.google.com with SMTP id g6so27758558ywa.13 for ; Fri, 08 Mar 2019 05:27:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=yqzTiUVyYLyv9KlkUwhxAc47WzGcrn+Wl93m1d0s4TI=; b=SUlH6DmgbaUC6Nvh5WLFxCglPyIMG0gZdXWMvoXDO/rSyOM9rfSkS7FA06gaADddoS +T87l6xR8oFCkJKa2PfVJfT1JGwrNZ+ZARhedauJEd/3UDjB6JcCUcpLtR74sYE2UCRP GQ0r5jm3pFB5rIl05jDolfafgKLu6Cy7AH0jzzeXlyYH3bmARC79/5bvp1BelL/cRvlo aIAM/btrCQYV6WtrRC56Ys9RwfOa1zCsmdBnhac3ALV1zc84WEubFvdQJq7DLyBkKrkZ crl1NY1EpSa6vRaCY0YRGhQHH/nXJN1Pd1vKa+jCNVq/tHLDqXTZasuhDHrMWWlaiyLi M29g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=yqzTiUVyYLyv9KlkUwhxAc47WzGcrn+Wl93m1d0s4TI=; b=AAoLTMY7HGIWLV6jkshZ82ZT1MBxUds5/9x+kwh5a1MBIMQap47ijg100BU1+0tHAd CPXOQa4J67ZGBdFpBu3RSyZ0Yg2L4NerWA0xBB6nvVK25YtpaVEhJNZNZ9eEDsq5Wd3g RGcNcSLXk8qKhIOeCfrS8m6Tk6qP3qutapl0oZfQ5YtLD67vHOee/PxbQJT3Cy4k8/f6 O/1yJGc0ms7O7HvpW4a7qGn7vKt4jCMdoDz9zu40nSl89MgM52HTA9f6NKbq/x5ICUWN uK/CLjlq61k7vJOSizk8QY9FC7BoOuSrcF547xgI0b/owze99skQ4gukwqQSnqTFJSse lejw== X-Gm-Message-State: APjAAAXxaZkeev5Sk9OMkhBpF/lVqt3pZjImw9fiFCbmSqXyAKnyPf+D ebB3B0tvP9KJdENwPD8+vJV4qnL/sm4= X-Google-Smtp-Source: APXvYqxKz4BvldII6JDKfVcbTdRjrj8iWTTtN2LnxMbKzD+Mub0f07BKOBXFWdUJ5jRGcSVvgfvlCXVGfKg= X-Received: by 2002:a81:b184:: with SMTP id p126mr8399501ywh.14.1552051635984; Fri, 08 Mar 2019 05:27:15 -0800 (PST) Date: Fri, 8 Mar 2019 14:27:01 +0100 In-Reply-To: <20190308132701.133598-1-glider@google.com> Message-Id: <20190308132701.133598-3-glider@google.com> Mime-Version: 1.0 References: <20190308132701.133598-1-glider@google.com> X-Mailer: git-send-email 2.21.0.360.g471c308f928-goog Subject: [PATCH v2 2/2] initmem: introduce CONFIG_INIT_ALL_HEAP From: Alexander Potapenko To: yamada.masahiro@socionext.com, jmorris@namei.org, serge@hallyn.com Cc: linux-security-module@vger.kernel.org, linux-kbuild@vger.kernel.org, ndesaulniers@google.com, kcc@google.com, dvyukov@google.com, keescook@chromium.org, sspatil@android.com, kernel-hardening@lists.openwall.com Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP This config option enables CONFIG_SLUB_DEBUG and CONFIG_PAGE_POISONING without the need to pass any boot parameters. No performance optimizations are done at the moment to reduce double initialization of memory regions. Signed-off-by: Alexander Potapenko Cc: Masahiro Yamada Cc: James Morris Cc: "Serge E. Hallyn" Cc: Nick Desaulniers Cc: Kostya Serebryany Cc: Dmitry Vyukov Cc: Kees Cook Cc: Sandeep Patil Cc: linux-security-module@vger.kernel.org Cc: linux-kbuild@vger.kernel.org Cc: kernel-hardening@lists.openwall.com --- mm/page_poison.c | 5 +++++ mm/slub.c | 2 ++ security/Kconfig.initmem | 11 +++++++++++ 3 files changed, 18 insertions(+) diff --git a/mm/page_poison.c b/mm/page_poison.c index 21d4f97cb49b..a1985f33f635 100644 --- a/mm/page_poison.c +++ b/mm/page_poison.c @@ -12,9 +12,14 @@ static bool want_page_poisoning __read_mostly; static int __init early_page_poison_param(char *buf) { +#ifdef CONFIG_INIT_ALL_HEAP + want_page_poisoning = true; + return 0; +#else if (!buf) return -EINVAL; return strtobool(buf, &want_page_poisoning); +#endif } early_param("page_poison", early_page_poison_param); diff --git a/mm/slub.c b/mm/slub.c index 1b08fbcb7e61..00e0197d3f35 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1287,6 +1287,8 @@ static int __init setup_slub_debug(char *str) if (*str == ',') slub_debug_slabs = str + 1; out: + if (IS_ENABLED(CONFIG_INIT_ALL_HEAP)) + slub_debug |= SLAB_POISON; return 1; } diff --git a/security/Kconfig.initmem b/security/Kconfig.initmem index 27aec394365e..5ce49663777a 100644 --- a/security/Kconfig.initmem +++ b/security/Kconfig.initmem @@ -13,6 +13,17 @@ config INIT_ALL_MEMORY if INIT_ALL_MEMORY +config INIT_ALL_HEAP + bool "Initialize all heap" + depends on INIT_ALL_MEMORY + select CONFIG_PAGE_POISONING + select CONFIG_PAGE_POISONING_NO_SANITY + select CONFIG_PAGE_POISONING_ZERO + select CONFIG_SLUB_DEBUG + default y + help + Enable page poisoning and slub poisoning by default. + config INIT_ALL_STACK bool "Initialize all stack" depends on INIT_ALL_MEMORY