From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=195.135.223.131 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793953296; b=pW7R3jbVw7vt2EgJ16PlVPHk+jtqXTxFp5JMrJiouDu9PbMPtYkhNuj+RvnTuSOfalOd c2waUkdeeyzn1lq2snBpkJdDbDbSS5itf+6yQAeTXYEiz5cbzFwLIKuowhDj1FImOh76I UqYDvuFl71SrIbQZNl8h2JZ1NJ/+g88dQ96+wkO1Wv9CYEsPqc7RgV4bA9M805jVGRLqB P3s68vHTH4DO186tL0sJ0p5klqFq4w0T/e2aeUp02YXd3fRDYoL7fMSjQReOnOoVeoZJx n1b+TbVWOhNgcYqwApVc7uNv5ezU7tp0gkypOq3ba22eCt9nUu+XYhkTvJENTPKmrtw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793953296; h=DMARC-Filter:Received:DKIM-Signature:DKIM-Signature:DKIM-Signature: DKIM-Signature:Received:Received:Message-ID:Date:MIME-Version: User-Agent:Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding:X-Rspamd-Queue-Id:X-Spam-Level: X-Rspamd-Server:X-Rspamd-Action:X-Spam-Flag:X-Spamd-Result: X-Spam-Score; bh=Z2Ju1cQkbqfSchQm4ea439mNBOoXAWoCo7WUPi9dWQU=; b=aBcHWfxI1f7ilVUOdxAxgwLMZPe9F2EoQAJTtCXiait9LCftuRwOvDAJPYovS7Z4EVLe wzNHFBy77BRb5MAniPdAHgo+cN6yyFG4tNETgY2Q91vOKF49OeptGIPx/7KwIIqAtnzK1 UHRx1JGO7GdYxPbDK3sCtS4Ye7/gbp5XFV6Vm/FmqCvLk91tpn+PUzL+7nGg7QsVMQJo8 KnP7sPBMAUJg65x/GmsQEjgQBGO3voErGFZpfU9yusiroUqGi/cz9dDOIFcinnW/t//b7 6hOYuWSkL4exGPK+RT5Bc5cdugL2pVxdUjpSnknvA9fb9ip7U9mQ/VmearsNKyL3dtg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=V4e5eAoA; dkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b="3u/TIF1Q"; dkim=pass header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=U40lI6F8; dkim=neutral header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=epjkPEdS; arc=none smtp.remote-ip=195.135.223.131 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 24135606A330; Fri, 6 Nov 2026 08:21:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 24135606A330 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=V4e5eAoA; dkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=3u/TIF1Q; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=U40lI6F8; dkim=neutral header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=epjkPEdS Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id EE3591FB93; Fri, 6 Nov 2026 08:21:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1793953294; 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=Z2Ju1cQkbqfSchQm4ea439mNBOoXAWoCo7WUPi9dWQU=; b=V4e5eAoAEcrMVPiURQAjginCIXmCcDDV6As0NtqHDwA3yiK2awePWJ2CRTFLJBufcxbk6v SWzt9hdEwkjKuP0L4WA90U3T9tQf68Bif5DvttfMuIsjdaMyfpNdO3eEvnGgn2x/tpalY5 np0yi/68rs46xpFXejPNMswmeEoi0D8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1793953294; 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=Z2Ju1cQkbqfSchQm4ea439mNBOoXAWoCo7WUPi9dWQU=; b=3u/TIF1Qfg3BoZVshE9rOBJ2ON+ybz08g6+kZZxQqx99cgMBDykCtrbAARoGIZzGPl9BCj e0CXdI0JHfJE23Aw== Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=U40lI6F8; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=epjkPEdS DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1793953293; 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=Z2Ju1cQkbqfSchQm4ea439mNBOoXAWoCo7WUPi9dWQU=; b=U40lI6F8wEBaSZ2brkRKY7emrMDprR6jHx07Go8XDqIDYEHXrXq5EDXDND/575qJEzvkT6 B7BU9RQ0+et4qoMWcBW52+8AzfnQB3J76HxGc1jcVyTFa6gmjl+GjTNgwNvyK9olKYpZZ6 rFi5WEZILTdEJxtTuHKBKgVltpgX+Mo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1793953293; 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=Z2Ju1cQkbqfSchQm4ea439mNBOoXAWoCo7WUPi9dWQU=; b=epjkPEdSL4wtMOZoeFcoy1kEE4pRVcMJ3AYKhXn+8eoImry0vFoijUAhqv85m3cIcLDM0g mWN/aMxISNozc8DA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id F035D132C9; Fri, 6 Nov 2026 08:21:32 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id JRMLKwyO7WqXcQAAD6G6ig (envelope-from ); Fri, 06 Nov 2026 08:21:32 +0000 Message-ID: <27015846-0161-4700-b810-4643e1f7b63a@suse.de> Date: Fri, 6 Nov 2026 09:21:32 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 2/3] KEYS: Replace assoc_array with rhashtable To: Jarkko Sakkinen , David Howells Cc: bpf@vger.kernel.org, dm-devel@lists.linux.dev, fsverity@lists.linux.dev, keyrings@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-security-module@vger.kernel.org, Alasdair Kergon , Alexei Starovoitov , Alex Shi , Andrew Morton , Andrii Nakryiko , Benjamin Marzinski , Daniel Borkmann , Dongliang Mu , Eduard Zingerman , Emil Tsalapatis , Eric Biggers , Ihor Solodrai , James Morris , Jiri Olsa , Jonathan Corbet , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Mike Snitzer , Mikulas Patocka , Paul Moore , Randy Dunlap , "Serge E. Hallyn" , Shuah Khan , Song Liu , "Theodore Y. Ts'o" , Yanteng Si , Yonghong Song , Linus Torvalds References: <20261105031401.956609-1-jarkko@kernel.org> <20261105031401.956609-3-jarkko@kernel.org> Content-Language: en-US From: Hannes Reinecke In-Reply-To: <20261105031401.956609-3-jarkko@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: EE3591FB93 X-Spam-Level: X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Action: no action X-Spam-Flag: NO X-Spamd-Result: default: False [-13.50 / 50.00]; SUSE_INTERNAL_BYPASS(-9.00)[]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; XM_UA_NO_VERSION(0.01)[]; MX_GOOD(-0.01)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; ARC_NA(0.00)[]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCPT_COUNT_TWELVE(0.00)[38]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[vger.kernel.org,lists.linux.dev,redhat.com,kernel.org,linux-foundation.org,iogearbox.net,hust.edu.cn,gmail.com,etsalapatis.com,linux.dev,namei.org,lwn.net,paul-moore.com,infradead.org,hallyn.com,linuxfoundation.org,mit.edu]; DKIM_TRACE(0.00)[suse.de:+]; TO_DN_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; DWL_DNSWL_BLOCKED(0.00)[suse.de:dkim]; R_RATELIMIT(0.00)[to_ip_from(RL3deh5x9onbckmuwxjk3fsykq)]; RCVD_VIA_SMTP_AUTH(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim,suse.de:email,imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo] X-Spam-Score: -13.50 On 11/5/26 4:14 AM, Jarkko Sakkinen wrote: > The keyrings subsystem is the sole user of assoc_array. It has over 1700 > lines of code, no test suite, and a long history of bugs, with LLMs now > finding more. > > This unfortunate outcome has evolved over time by large from the shortage > of in-kernel callers, time bandwidth and 3rd party contributors. > > What the keyrings needs is just a generic key-value store, which performs > well with sparse key sets. > > Replace struct assoc_array in struct key with struct keyring_index: > > - keyring_index: holds an rhashtable for direct lookups, an RCU-protected > list of keyring_link entries for stable walks, the active link count, and > an rcu_work item for deferred teardown. > - keyring_link: links a key into a keyring's hash table and list, caching > its 32-bit SipHash digest rehashed with jhash by rhashtable. > > Correspondingly, struct assoc_array_edit is replaced by struct keyring_edit > for delivering transient state across link operations. > > Other behavioral changes: > > - KEYCTL_READ and sibling-keyring searches follow list order instead of > hash order: keyrings are prepended, other keys are appended, and > replacing a matching key retains its position. > - key_unlink(), keyring_clear(), keyring_revoke(), and keyring_gc() no > longer allocate memory. > - keyring_index_free() uses queue_rcu_work() instead of call_rcu() because > rhashtable_destroy() may sleep. > > Suggested-by: Eric Biggers > Co-developed-by: Linus Torvalds > Signed-off-by: Linus Torvalds > Signed-off-by: Jarkko Sakkinen > --- > include/keys/keyring-type.h | 1 - > include/linux/key-type.h | 1 - > include/linux/key.h | 28 +- > security/keys/Kconfig | 1 - > security/keys/internal.h | 14 +- > security/keys/key.c | 22 +- > security/keys/keyring.c | 986 ++++++++++++++++-------------------- > security/keys/request_key.c | 8 +- > 8 files changed, 465 insertions(+), 596 deletions(-) > While I am pretty much in favour with this approach, is there a specific reason why siphash has been chosen? Would there be a chance to make this configurable? I do see slight complications when running in secure environments (ie FIPS-certified environments) where most of the hash functions might not be available ... Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich