From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8A54C7EE2D for ; Tue, 23 May 2023 07:48:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235471AbjEWHsT (ORCPT ); Tue, 23 May 2023 03:48:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235752AbjEWHrU (ORCPT ); Tue, 23 May 2023 03:47:20 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 756C61BB; Tue, 23 May 2023 00:46:49 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id F346E2278E; Tue, 23 May 2023 07:46:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1684828008; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=58gO67C02CVMHG9L5fQR2UaHS2Sy9GihYlrPMDsOtdY=; b=2d+tgN4NQAeqxQf9muy2Hs6z+gOqwlZz4sB110Vo8C97eAyDWV2FPNgr4+XERj/fbPnR7K dKoqBODa6I5DFBvgybWFUKX4WnnkZxulc98WwRZ4ciQI6D3KH6jdOLSPOQjCjqTwm9l6TB 3hxPKIlmiAzYOa6yDUAIgwuebGO9o00= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1684828008; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=58gO67C02CVMHG9L5fQR2UaHS2Sy9GihYlrPMDsOtdY=; b=z9+bPFWJb5h70YdzRwLa7N6xoz226Vn0mVd4Gpx00kLlbTL3VVlAq1PFoiR8eE+Hwyog7Y dH9YZUh21MvLfvBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 56AF913588; Tue, 23 May 2023 07:46:47 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id gk7hE2dvbGTgJwAAMHmgww (envelope-from ); Tue, 23 May 2023 07:46:47 +0000 Message-ID: <623a87c6-c0d2-799a-c39e-0d14dcdfa6df@suse.cz> Date: Tue, 23 May 2023 09:46:46 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH] mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR Content-Language: en-US To: Lorenzo Stoakes Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Kees Cook , linux-mm@kvack.org, linux-hardening@vger.kernel.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org References: <20230523073136.4900-1-vbabka@suse.cz> <310077ed-6f3f-41fe-afcf-36500a9408ec@lucifer.local> From: Vlastimil Babka In-Reply-To: <310077ed-6f3f-41fe-afcf-36500a9408ec@lucifer.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On 5/23/23 09:42, Lorenzo Stoakes wrote: > On Tue, May 23, 2023 at 09:31:36AM +0200, Vlastimil Babka wrote: >> With SLOB removed, both remaining allocators support hardened usercopy, >> so remove the config and associated #ifdef. >> >> Signed-off-by: Vlastimil Babka >> --- >> mm/Kconfig | 2 -- >> mm/slab.h | 9 --------- >> security/Kconfig | 8 -------- >> 3 files changed, 19 deletions(-) >> >> diff --git a/mm/Kconfig b/mm/Kconfig >> index 7672a22647b4..041f0da42f2b 100644 >> --- a/mm/Kconfig >> +++ b/mm/Kconfig >> @@ -221,7 +221,6 @@ choice >> config SLAB >> bool "SLAB" >> depends on !PREEMPT_RT >> - select HAVE_HARDENED_USERCOPY_ALLOCATOR >> help >> The regular slab allocator that is established and known to work >> well in all environments. It organizes cache hot objects in >> @@ -229,7 +228,6 @@ 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/slab.h b/mm/slab.h >> index f01ac256a8f5..695ef96b4b5b 100644 >> --- a/mm/slab.h >> +++ b/mm/slab.h >> @@ -832,17 +832,8 @@ struct kmem_obj_info { >> void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab); >> #endif >> >> -#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR >> void __check_heap_object(const void *ptr, unsigned long n, >> const struct slab *slab, bool to_user); >> -#else >> -static inline >> -void __check_heap_object(const void *ptr, unsigned long n, >> - const struct slab *slab, bool to_user) >> -{ >> -} >> -#endif > > Hm, this is still defined in slab.c/slub.c and invoked in usercopy.c, do we > not want the prototype? Well I didn't delete the prototype, just the ifdef/else around, so now it's there unconditionally. > Perhaps replacing with #ifdef > CONFIG_HARDENED_USERCOPY instead? I may be missing something here :) Putting it under that #ifdef would work and match that the implementations of that function are under that same ifdef, but maybe it's unnecessary noise in the header?