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 C4FA3C433EF for ; Mon, 27 Dec 2021 19:04:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232193AbhL0TE1 (ORCPT ); Mon, 27 Dec 2021 14:04:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56516 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231987AbhL0TEP (ORCPT ); Mon, 27 Dec 2021 14:04:15 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 104B3C061761; Mon, 27 Dec 2021 11:04:15 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A501761151; Mon, 27 Dec 2021 19:04:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EA43C36AEB; Mon, 27 Dec 2021 19:04:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1640631854; bh=BZ20Galzn1I8vy3gFLN6Zn7/ni5xt6lwWKK/pr0QZBo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SpY6zarmmcc6Cti2XzuqXu9gqgJEAIFE3hPbw31oJrP8vmtONkngAV5/2Ru7ZyWBK usPxZ6Rt+VouPHUg8ptwLp8cdfmqEYbxjov8swQad/6CQuaCT7ON1uebVgmWJZWENJ xu1833Jy4kClXTuUXbOEkxRvCtEAr4TFmpU5TdVyVAyAkQeDKDZvcdypbbCQGyy1W7 Fq3R3PRSjAVqEaBU56R8jWAB07lsq2eWL77/S2EaZ7c0pBFQpgH+Kf+BeK8VVWZvOg j6ak+II4Ml5SXki+EXWyX0N/5P//8U2Udd9XNTejfycYFz86chuxrNLjBZx4f8z9DQ fXc1xjLiQQJ6A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Vyukov , Tetsuo Handa , Sasha Levin , takedakn@nttdata.co.jp, jmorris@namei.org, serge@hallyn.com, linux-security-module@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 12/26] tomoyo: Check exceeded quota early in tomoyo_domain_quota_is_ok(). Date: Mon, 27 Dec 2021 14:03:13 -0500 Message-Id: <20211227190327.1042326-12-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211227190327.1042326-1-sashal@kernel.org> References: <20211227190327.1042326-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dmitry Vyukov [ Upstream commit 04e57a2d952bbd34bc45744e72be3eecdc344294 ] If tomoyo is used in a testing/fuzzing environment in learning mode, for lots of domains the quota will be exceeded and stay exceeded for prolonged periods of time. In such cases it's pointless (and slow) to walk the whole acl list again and again just to rediscover that the quota is exceeded. We already have the TOMOYO_DIF_QUOTA_WARNED flag that notes the overflow condition. Check it early to avoid the slowdown. [penguin-kernel] This patch causes a user visible change that the learning mode will not be automatically resumed after the quota is increased. To resume the learning mode, administrator will need to explicitly clear TOMOYO_DIF_QUOTA_WARNED flag after increasing the quota. But I think that this change is generally preferable, for administrator likely wants to optimize the acl list for that domain before increasing the quota, or that domain likely hits the quota again. Therefore, don't try to care to clear TOMOYO_DIF_QUOTA_WARNED flag automatically when the quota for that domain changed. Signed-off-by: Dmitry Vyukov Signed-off-by: Tetsuo Handa Signed-off-by: Sasha Levin --- security/tomoyo/util.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c index 1da2e3722b126..af8cd2af3466d 100644 --- a/security/tomoyo/util.c +++ b/security/tomoyo/util.c @@ -1051,6 +1051,8 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r) return false; if (!domain) return true; + if (READ_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED])) + return false; list_for_each_entry_rcu(ptr, &domain->acl_info_list, list, srcu_read_lock_held(&tomoyo_ss)) { u16 perm; @@ -1096,14 +1098,12 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r) if (count < tomoyo_profile(domain->ns, domain->profile)-> pref[TOMOYO_PREF_MAX_LEARNING_ENTRY]) return true; - if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) { - domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true; - /* r->granted = false; */ - tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]); + WRITE_ONCE(domain->flags[TOMOYO_DIF_QUOTA_WARNED], true); + /* r->granted = false; */ + tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]); #ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING - pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n", - domain->domainname->name); + pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n", + domain->domainname->name); #endif - } return false; } -- 2.34.1