From patchwork Fri Jul 15 21:44:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9232831 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 3D80060868 for ; Fri, 15 Jul 2016 21:52:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2C982262F2 for ; Fri, 15 Jul 2016 21:52:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 206F427BFC; Fri, 15 Jul 2016 21:52:48 +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=unavailable 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 A16AB262F2 for ; Fri, 15 Jul 2016 21:52:47 +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 1bOB06-0007gY-R8; Fri, 15 Jul 2016 21:50:26 +0000 Received: from mail-pf0-x22e.google.com ([2607:f8b0:400e:c00::22e]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bOAuq-0001e9-9s for linux-arm-kernel@lists.infradead.org; Fri, 15 Jul 2016 21:45:04 +0000 Received: by mail-pf0-x22e.google.com with SMTP id p64so11084699pfb.1 for ; Fri, 15 Jul 2016 14:44:40 -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=0MPQsN6aA0t9gZEW0aiBDC5li+z+8lKE/uD//oHccL0=; b=YghDCwkheg3g9Bt6VNcF/MwNsQWVwfBKVZEm/sRBOgG7pP1sfW3UXBLO0CRtNyNb/J N1ShChds/21AIqvPAq9npcMt++XptJj4klZOJGOnFoqn72QyNHC8bDzqrrKoPTy1kiVe fyInMLgjKPwg8cPXL5V+CsSlXsMtzwBvUjAOk= 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=0MPQsN6aA0t9gZEW0aiBDC5li+z+8lKE/uD//oHccL0=; b=IkopS0lP5faCKyHBeh7lBcCvydguGnO1+vSp61/vg3lPVwBAaaDk828+Hruhmka4Xc aDRXX3rKWvEL5JncTd2EGe/g6xPdWMD0kEtACKt2Bg9463watbTZNiYocJsxcY9iMbYc vfFRfM3iJPMQIRCMDAYqq/l4tLhXF/o3QwOPQ4NCgWXOLMXtuwfhjNIpi32dW1497LD/ phh2zztv/YNMG3xxEPN2/BdnmjyiPnoQHoHpQ5HukjD7M8FehHBaLT+MSZU4OabLyMLr W8ajFfo+WJNCVWb5pIDA4La8yi/O/5/G1DaiOc6D0XaHu3n3QvVeGA+f4HasEmrSYA9f J7Tg== X-Gm-Message-State: ALyK8tLqFEPBLIcO0LwC01PfkOvK0rVjZEx2wGj0eMv8IARd77M2rHYTjhsoZnOL1oRYshq+ X-Received: by 10.98.94.135 with SMTP id s129mr25466189pfb.31.1468619079604; Fri, 15 Jul 2016 14:44:39 -0700 (PDT) Received: from www.outflux.net ([2002:ada4:7085:0:ae16:2dff:fe07:4fb6]) by smtp.gmail.com with ESMTPSA id sp5sm6746843pac.37.2016.07.15.14.44.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Jul 2016 14:44:35 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Subject: [PATCH v3 11/11] mm: SLUB hardened usercopy support Date: Fri, 15 Jul 2016 14:44:25 -0700 Message-Id: <1468619065-3222-12-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1468619065-3222-1-git-send-email-keescook@chromium.org> References: <1468619065-3222-1-git-send-email-keescook@chromium.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160715_144500_699310_99D2680E X-CRM114-Status: GOOD ( 14.80 ) 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, Benjamin Herrenschmidt , Balbir Singh , 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, Catalin Marinas , PaX Team , Borislav Petkov , Mathias Krause , Fenghua Yu , Rik van Riel , Kees Cook , Vitaly Wool , David Rientjes , Tony Luck , Andy Lutomirski , Josh Poimboeuf , Andrew Morton , Dmitry Vyukov , Laura Abbott , Brad Spengler , Ard Biesheuvel , Pekka Enberg , Daniel Micay , Casey Schaufler , Joonsoo Kim , 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. Includes a redzone handling fix discovered by Michael Ellerman. Based on code from PaX and grsecurity. Signed-off-by: Kees Cook Tested-by: Michael Ellerman --- init/Kconfig | 1 + mm/slub.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 37 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..7dee3d9a5843 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3614,6 +3614,42 @@ 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; + size_t object_size; + + /* Find object and usable object size. */ + s = page->slab_cache; + object_size = slab_ksize(s); + + /* Find offset within object. */ + offset = (ptr - page_address(page)) % s->size; + + /* Adjust for redzone and reject if within the redzone. */ + if (kmem_cache_debug(s) && s->flags & SLAB_RED_ZONE) { + if (offset < s->red_left_pad) + return s->name; + offset -= s->red_left_pad; + } + + /* Allow address range falling entirely within object size. */ + if (offset <= object_size && n <= object_size - offset) + return NULL; + + return s->name; +} +#endif /* CONFIG_HARDENED_USERCOPY */ + static size_t __ksize(const void *object) { struct page *page;