From patchwork Wed Jul 6 22:25:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 645611 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3rlFjT1rBgz9spN for ; Thu, 7 Jul 2016 08:26:53 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.b=iGFDcGNT; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755923AbcGFW0O (ORCPT ); Wed, 6 Jul 2016 18:26:14 -0400 Received: from mail-pf0-f175.google.com ([209.85.192.175]:34206 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932298AbcGFWZs (ORCPT ); Wed, 6 Jul 2016 18:25:48 -0400 Received: by mail-pf0-f175.google.com with SMTP id h14so132515pfe.1 for ; Wed, 06 Jul 2016 15:25:47 -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:in-reply-to:references; bh=kAvQEYCv81LFkI1VrCzJn97Rh6WSqYJREjQTwZm00ts=; b=iGFDcGNTJNsQ/EGSDzPz6KeuLCegtTZXpE+wec+iEri5FrPMSUEC+PYPedsbp+Xavv zm7ob7j7Aw+6PrjBv1Aq6rLJdd6Rrrke2HmB9AKsNzN6VFevlyoDBuLP7oXSgO70m8CC 3j6D1+8xaFAXvhc5Hv5LpbvOZ0qHQ4Bsj2Osk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=kAvQEYCv81LFkI1VrCzJn97Rh6WSqYJREjQTwZm00ts=; b=HCjeHvgBsez6cNqlq8B8eNNRbWZBsS9DvdJpXr+Igd17GHMVSZFBM89fHaUJObeoPK XzOT/5yXUf8KfBA1Qd1zZ4hVQ/rCApF1aSl3beQOU7UtPFEBiDh3dEyRJ6nlVpqaD8/o VtmkTEytIMxYfiUhwRyTi7jOOFqRSL75IivYkFWxBEfILh1Nkkcvbg5n6Cl8nOeUx407 2VIP6+OaiXz/QHiwEmRgbJNiVtKp++Qkq6K8J3QD922J4gN1B6tFiPXHa6Y90fOQSLgu 9+GryR20K9ZCYNZ2nm+g7cHFkI2Q3Iq8IRr9EJvh9MZ+y/mquYhLRIGKqYum7y1Lj6jk eeCA== X-Gm-Message-State: ALyK8tJhT6YrhidHIRtacV5KabITa83SpdF6X6FpTufTe7lo1PvGalPfUmFVgNFUceP0klG4 X-Received: by 10.98.152.210 with SMTP id d79mr45956342pfk.2.1467843947266; Wed, 06 Jul 2016 15:25:47 -0700 (PDT) Received: from www.outflux.net (173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133]) by smtp.gmail.com with ESMTPSA id yt4sm6640441pab.26.2016.07.06.15.25.45 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 06 Jul 2016 15:25:46 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Rik van Riel , Casey Schaufler , PaX Team , Brad Spengler , Russell King , Catalin Marinas , Will Deacon , Ard Biesheuvel , Benjamin Herrenschmidt , Michael Ellerman , Tony Luck , Fenghua Yu , "David S. Miller" , x86@kernel.org, Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Andy Lutomirski , Borislav Petkov , Mathias Krause , Jan Kara , Vitaly Wool , Andrea Arcangeli , Dmitry Vyukov , Laura Abbott , linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com Subject: [PATCH 9/9] mm: SLUB hardened usercopy support Date: Wed, 6 Jul 2016 15:25:28 -0700 Message-Id: <1467843928-29351-10-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1467843928-29351-1-git-send-email-keescook@chromium.org> References: <1467843928-29351-1-git-send-email-keescook@chromium.org> Sender: sparclinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the SLUB allocator to catch any copies that may span objects. Based on code from PaX and grsecurity. Signed-off-by: Kees Cook --- init/Kconfig | 1 + mm/slub.c | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/init/Kconfig b/init/Kconfig index 798c2020ee7c..1c4711819dfd 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1765,6 +1765,7 @@ config SLAB config SLUB bool "SLUB (Unqueued Allocator)" + select HAVE_HARDENED_USERCOPY_ALLOCATOR help SLUB is a slab allocator that minimizes cache line usage instead of managing queues of cached objects (SLAB approach). diff --git a/mm/slub.c b/mm/slub.c index 825ff4505336..0c8ace04f075 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3614,6 +3614,33 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node) EXPORT_SYMBOL(__kmalloc_node); #endif +#ifdef CONFIG_HARDENED_USERCOPY +/* + * Rejects objects that are incorrectly sized. + * + * Returns NULL if check passes, otherwise const char * to name of cache + * to indicate an error. + */ +const char *__check_heap_object(const void *ptr, unsigned long n, + struct page *page) +{ + struct kmem_cache *s; + unsigned long offset; + + /* Find object. */ + s = page->slab_cache; + + /* Find offset within object. */ + offset = (ptr - page_address(page)) % s->size; + + /* Allow address range falling entirely within object size. */ + if (offset <= s->object_size && n <= s->object_size - offset) + return NULL; + + return s->name; +} +#endif /* CONFIG_HARDENED_USERCOPY */ + static size_t __ksize(const void *object) { struct page *page;