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: 9217179 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DE6B660467 for ; Wed, 6 Jul 2016 22:28:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CA903284DF for ; Wed, 6 Jul 2016 22:28:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BCDB8284E5; Wed, 6 Jul 2016 22:28:52 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9416D284DF for ; Wed, 6 Jul 2016 22:28:51 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bKvHq-0003vL-4i; Wed, 06 Jul 2016 22:27:18 +0000 Received: from mail-pf0-x22b.google.com ([2607:f8b0:400e:c00::22b]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bKvGh-0002ix-BK for linux-arm-kernel@lists.infradead.org; Wed, 06 Jul 2016 22:26:09 +0000 Received: by mail-pf0-x22b.google.com with SMTP id c2so121526pfa.2 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=gLOn5PHklhwjrppNuMhZoP5TVif8C1WYqchPMqwbfdjd5nbsJdx1Rn/YHYBe+SaSGu oSfMmSn+KoRMLUskKCT5fMc8Hf14et8YQE4EoEWa79lFUanMp3HDzAB1NAazS6Gd7za5 MlZmpGGY17G6teG51IvCDBMq5aPXny06MtPHNHo1i/YBh6EPOxc3QBR849USuHtl/pyP SqfZkfRIGad6pIhSB4iyZdCYfngyyzwBgd5acD8KKXCy4Aj3u/38VlcSQdCsVejybuEj IVJeMfZc+Uy4txQqkXsORXYcZyyJu6P/UrBUXu6AWPbtlOV/W46vuZmCrcGrc8ideu7z zMNw== X-Gm-Message-State: ALyK8tLXkf9bwSLRO/rp98DF9M33db/lgiRyENNodjmSET/JBl3djDqbxgPlhA3+cqYOimtq 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 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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160706_152607_533923_86A49054 X-CRM114-Status: GOOD ( 13.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , kernel-hardening@lists.openwall.com, Catalin Marinas , Will Deacon , linux-mm@kvack.org, sparclinux@vger.kernel.org, linux-ia64@vger.kernel.org, Christoph Lameter , Andrea Arcangeli , linux-arch@vger.kernel.org, Michael Ellerman , x86@kernel.org, Russell King , linux-arm-kernel@lists.infradead.org, Benjamin Herrenschmidt , PaX Team , Borislav Petkov , Mathias Krause , Fenghua Yu , Rik van Riel , Kees Cook , Vitaly Wool , David Rientjes , Tony Luck , Andy Lutomirski , Joonsoo Kim , Dmitry Vyukov , Laura Abbott , Brad Spengler , Ard Biesheuvel , Pekka Enberg , Casey Schaufler , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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;