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 X-Spam-Level: X-Spam-Status: No, score=-12.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A492FC4742C for ; Mon, 2 Nov 2020 16:52:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7442622277 for ; Mon, 2 Nov 2020 16:52:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727416AbgKBQwd (ORCPT ); Mon, 2 Nov 2020 11:52:33 -0500 Received: from raptor.unsafe.ru ([5.9.43.93]:51612 "EHLO raptor.unsafe.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726920AbgKBQwc (ORCPT ); Mon, 2 Nov 2020 11:52:32 -0500 Received: from comp-core-i7-2640m-0182e6.redhat.com (ip-89-103-122-167.net.upcbroadband.cz [89.103.122.167]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by raptor.unsafe.ru (Postfix) with ESMTPSA id 0DDD420A06; Mon, 2 Nov 2020 16:52:30 +0000 (UTC) From: Alexey Gladkov To: LKML , Linux Containers , Kernel Hardening Cc: Alexey Gladkov , "Eric W . Biederman" , Kees Cook , Christian Brauner Subject: [RFC PATCH v1 1/4] Increase size of ucounts to atomic_long_t Date: Mon, 2 Nov 2020 17:50:30 +0100 Message-Id: X-Mailer: git-send-email 2.25.4 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.6.1 (raptor.unsafe.ru [5.9.43.93]); Mon, 02 Nov 2020 16:52:30 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to be able to use ucounts for rlimits, the size must be increased. For example user_struct.mq_bytes (RLIMIT_MSGQUEUE) is unsigned long. Signed-off-by: Alexey Gladkov --- include/linux/user_namespace.h | 4 ++-- kernel/ucount.c | 14 +++++++------- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 6ef1c7109fc4..fc75af812d73 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -86,7 +86,7 @@ struct user_namespace { struct ctl_table_header *sysctls; #endif struct ucounts *ucounts; - int ucount_max[UCOUNT_COUNTS]; + long ucount_max[UCOUNT_COUNTS]; } __randomize_layout; struct ucounts { @@ -94,7 +94,7 @@ struct ucounts { struct user_namespace *ns; kuid_t uid; int count; - atomic_t ucount[UCOUNT_COUNTS]; + atomic_long_t ucount[UCOUNT_COUNTS]; }; extern struct user_namespace init_user_ns; diff --git a/kernel/ucount.c b/kernel/ucount.c index 11b1596e2542..7b2bca8582ef 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -175,14 +175,14 @@ static void put_ucounts(struct ucounts *ucounts) kfree(ucounts); } -static inline bool atomic_inc_below(atomic_t *v, int u) +static inline bool atomic_long_inc_below(atomic_long_t *v, int u) { - int c, old; - c = atomic_read(v); + long c, old; + c = atomic_long_read(v); for (;;) { if (unlikely(c >= u)) return false; - old = atomic_cmpxchg(v, c, c+1); + old = atomic_long_cmpxchg(v, c, c+1); if (likely(old == c)) return true; c = old; @@ -199,14 +199,14 @@ struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, int max; tns = iter->ns; max = READ_ONCE(tns->ucount_max[type]); - if (!atomic_inc_below(&iter->ucount[type], max)) + if (!atomic_long_inc_below(&iter->ucount[type], max)) goto fail; } return ucounts; fail: bad = iter; for (iter = ucounts; iter != bad; iter = iter->ns->ucounts) - atomic_dec(&iter->ucount[type]); + atomic_long_dec(&iter->ucount[type]); put_ucounts(ucounts); return NULL; @@ -216,7 +216,7 @@ void dec_ucount(struct ucounts *ucounts, enum ucount_type type) { struct ucounts *iter; for (iter = ucounts; iter; iter = iter->ns->ucounts) { - int dec = atomic_dec_if_positive(&iter->ucount[type]); + int dec = atomic_long_dec_if_positive(&iter->ucount[type]); WARN_ON_ONCE(dec < 0); } put_ucounts(ucounts); -- 2.25.4