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 CCDB9C433EF for ; Mon, 29 Nov 2021 20:40:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232864AbhK2Unq convert rfc822-to-8bit (ORCPT ); Mon, 29 Nov 2021 15:43:46 -0500 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:50549 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233817AbhK2Ulq (ORCPT ); Mon, 29 Nov 2021 15:41:46 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-158-Ra-yvdlmPje_XcZzTDOEeA-1; Mon, 29 Nov 2021 15:38:24 -0500 X-MC-Unique: Ra-yvdlmPje_XcZzTDOEeA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BE8E683DD20; Mon, 29 Nov 2021 20:38:22 +0000 (UTC) Received: from comp-core-i7-2640m-0182e6.redhat.com (unknown [10.36.110.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id 27AD310013D6; Mon, 29 Nov 2021 20:38:20 +0000 (UTC) From: Alexey Gladkov To: LKML , Linux Containers Cc: 0day robot , "Eric W . Biederman" , lkp@lists.01.org, kernel test robot Subject: [PATCH v2 2/2] ucounts: Move rlimit max values from ucounts max Date: Mon, 29 Nov 2021 21:37:26 +0100 Message-Id: <24c87e225c7950bf2ea1ff4b4a8f237348808241.1638218242.git.legion@kernel.org> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=legion@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset=WINDOWS-1252 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since the semantics of maximum rlimit values are different, they need to be separated from ucount_max. This will prevent the error of using inc_count/dec_ucount for rlimit parameters. This patch also renames the functions to emphasize the lack of connection between rlimit_max and ucount_max. v2: - Fix the array-index-out-of-bounds that was found by the lkp project. Reported-by: kernel test robot Signed-off-by: Alexey Gladkov --- include/linux/user_namespace.h | 17 ++++++++++++----- kernel/fork.c | 10 +++++----- kernel/ucount.c | 10 +++------- kernel/user_namespace.c | 10 +++++----- 4 files changed, 25 insertions(+), 22 deletions(-) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 33a4240e6a6f..812b6935f4a3 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -58,10 +58,11 @@ enum ucount_type { UCOUNT_RLIMIT_MSGQUEUE, UCOUNT_RLIMIT_SIGPENDING, UCOUNT_RLIMIT_MEMLOCK, - UCOUNT_COUNTS, + UCOUNT_ALL_COUNTS, }; -#define MAX_PER_NAMESPACE_UCOUNTS UCOUNT_RLIMIT_NPROC +#define UCOUNT_COUNTS UCOUNT_RLIMIT_NPROC +#define RLIMIT_COUNTS UCOUNT_ALL_COUNTS - UCOUNT_COUNTS + 1 struct user_namespace { struct uid_gid_map uid_map; @@ -99,6 +100,7 @@ struct user_namespace { #endif struct ucounts *ucounts; long ucount_max[UCOUNT_COUNTS]; + long rlimit_max[RLIMIT_COUNTS]; } __randomize_layout; struct ucounts { @@ -106,7 +108,7 @@ struct ucounts { struct user_namespace *ns; kuid_t uid; atomic_t count; - atomic_long_t ucount[UCOUNT_COUNTS]; + atomic_long_t ucount[UCOUNT_ALL_COUNTS]; }; extern struct user_namespace init_user_ns; @@ -131,10 +133,15 @@ long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type); void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum ucount_type type); bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max); -static inline void set_rlimit_ucount_max(struct user_namespace *ns, +static inline long get_userns_rlimit_max(struct user_namespace *ns, enum ucount_type type) +{ + return READ_ONCE(ns->rlimit_max[type - UCOUNT_COUNTS]); +} + +static inline void set_userns_rlimit_max(struct user_namespace *ns, enum ucount_type type, unsigned long max) { - ns->ucount_max[type] = max <= LONG_MAX ? max : LONG_MAX; + ns->rlimit_max[type - UCOUNT_COUNTS] = max <= LONG_MAX ? max : LONG_MAX; } #ifdef CONFIG_USER_NS diff --git a/kernel/fork.c b/kernel/fork.c index 3244cc56b697..365819458030 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -836,13 +836,13 @@ void __init fork_init(void) init_task.signal->rlim[RLIMIT_SIGPENDING] = init_task.signal->rlim[RLIMIT_NPROC]; - for (i = 0; i < MAX_PER_NAMESPACE_UCOUNTS; i++) + for (i = 0; i < UCOUNT_COUNTS; i++) init_user_ns.ucount_max[i] = max_threads/2; - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_NPROC, RLIM_INFINITY); - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_MSGQUEUE, RLIM_INFINITY); - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_SIGPENDING, RLIM_INFINITY); - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_MEMLOCK, RLIM_INFINITY); + set_userns_rlimit_max(&init_user_ns, UCOUNT_RLIMIT_NPROC, RLIM_INFINITY); + set_userns_rlimit_max(&init_user_ns, UCOUNT_RLIMIT_MSGQUEUE, RLIM_INFINITY); + set_userns_rlimit_max(&init_user_ns, UCOUNT_RLIMIT_SIGPENDING, RLIM_INFINITY); + set_userns_rlimit_max(&init_user_ns, UCOUNT_RLIMIT_MEMLOCK, RLIM_INFINITY); #ifdef CONFIG_VMAP_STACK cpuhp_setup_state(CPUHP_BP_PREPARE_DYN, "fork:vm_stack_cache", diff --git a/kernel/ucount.c b/kernel/ucount.c index 7b32c356ebc5..ffffcfae8474 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -87,10 +87,6 @@ static struct ctl_table user_table[] = { UCOUNT_ENTRY("max_fanotify_groups"), UCOUNT_ENTRY("max_fanotify_marks"), #endif - { }, - { }, - { }, - { }, { } }; #endif /* CONFIG_SYSCTL */ @@ -273,7 +269,7 @@ long inc_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v) ret = LONG_MAX; else if (iter == ucounts) ret = new; - max = READ_ONCE(iter->ns->ucount_max[type]); + max = get_userns_rlimit_max(iter->ns, type); } return ret; } @@ -322,7 +318,7 @@ long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type) goto unwind; if (iter == ucounts) ret = new; - max = READ_ONCE(iter->ns->ucount_max[type]); + max = get_userns_rlimit_max(iter->ns, type); /* * Grab an extra ucount reference for the caller when * the rlimit count was previously 0. @@ -350,7 +346,7 @@ bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsign for (iter = ucounts; iter; iter = iter->ns->ucounts) { if (get_ucounts_value(iter, type) > max) return true; - max = READ_ONCE(iter->ns->ucount_max[type]); + max = get_userns_rlimit_max(iter->ns, type); } return false; } diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 6b2e3ca7ee99..b9f6729b4e5f 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -119,13 +119,13 @@ int create_user_ns(struct cred *new) ns->owner = owner; ns->group = group; INIT_WORK(&ns->work, free_user_ns); - for (i = 0; i < MAX_PER_NAMESPACE_UCOUNTS; i++) { + for (i = 0; i < UCOUNT_COUNTS; i++) { ns->ucount_max[i] = INT_MAX; } - set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)); - set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_MSGQUEUE, rlimit(RLIMIT_MSGQUEUE)); - set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_SIGPENDING, rlimit(RLIMIT_SIGPENDING)); - set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_MEMLOCK, rlimit(RLIMIT_MEMLOCK)); + set_userns_rlimit_max(ns, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)); + set_userns_rlimit_max(ns, UCOUNT_RLIMIT_MSGQUEUE, rlimit(RLIMIT_MSGQUEUE)); + set_userns_rlimit_max(ns, UCOUNT_RLIMIT_SIGPENDING, rlimit(RLIMIT_SIGPENDING)); + set_userns_rlimit_max(ns, UCOUNT_RLIMIT_MEMLOCK, rlimit(RLIMIT_MEMLOCK)); ns->ucounts = ucounts; /* Inherit USERNS_SETGROUPS_ALLOWED from our parent */ -- 2.33.0