From patchwork Wed Jul 6 23:39:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908907 X-Patchwork-Delegate: kuba@kernel.org 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 BEC72C43334 for ; Wed, 6 Jul 2022 23:41:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234697AbiGFXlL (ORCPT ); Wed, 6 Jul 2022 19:41:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234645AbiGFXlJ (ORCPT ); Wed, 6 Jul 2022 19:41:09 -0400 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E21B2CDF0; Wed, 6 Jul 2022 16:41:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150869; x=1688686869; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3AizaG7JVuBeW6Yfn7ur25n7TaxfVztdrQf/wvDkjuY=; b=f5R4XmCFarbtbZqmIFlc8FfVwOyKOTaaM6pOwPAFjQuGEJas+pyVQrNn gczVJvR5dtO9GW88hiNw0fs4nPpViRUYJbjXCxgejPn3qaIUiGTaHvaVI IP5V5AtHDb/scgSDpiOEC62JiRlgRoJDZffJ7Yp9ymA47e0d9AWTvwsQx I=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="235612667" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1box-d-0e176545.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP; 06 Jul 2022 23:40:54 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1box-d-0e176545.us-east-1.amazon.com (Postfix) with ESMTPS id CE02B2E001F; Wed, 6 Jul 2022 23:40:50 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:40:49 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:40:46 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 01/12] sysctl: Fix data races in proc_dointvec(). Date: Wed, 6 Jul 2022 16:39:52 -0700 Message-ID: <20220706234003.66760-2-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch changes proc_dointvec() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_dointvec() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- kernel/sysctl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e52b6e372c60..c8a05655ae60 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -446,14 +446,14 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, if (*negp) { if (*lvalp > (unsigned long) INT_MAX + 1) return -EINVAL; - *valp = -*lvalp; + WRITE_ONCE(*valp, -*lvalp); } else { if (*lvalp > (unsigned long) INT_MAX) return -EINVAL; - *valp = *lvalp; + WRITE_ONCE(*valp, *lvalp); } } else { - int val = *valp; + int val = READ_ONCE(*valp); if (val < 0) { *negp = true; *lvalp = -(unsigned long)val; From patchwork Wed Jul 6 23:39:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908908 X-Patchwork-Delegate: kuba@kernel.org 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 EF7B5C43334 for ; Wed, 6 Jul 2022 23:41:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234774AbiGFXlc (ORCPT ); Wed, 6 Jul 2022 19:41:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234764AbiGFXl2 (ORCPT ); Wed, 6 Jul 2022 19:41:28 -0400 Received: from smtp-fw-33001.amazon.com (smtp-fw-33001.amazon.com [207.171.190.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 274A22CDF8; Wed, 6 Jul 2022 16:41:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150885; x=1688686885; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qq/qfg904mjSo0orEnGORfkoNOzm2AdQkoF/vSc53Nw=; b=arfm/cTpeXAJ538ldX3l9TKlU2A8K1SqqSIJq3OpGKv7cBXd/tG88RgH SyxLVAiVk3Dk74/PGv77KlZpYVIVM1Uq6Q0PVfUH5ZmpjYcouRNuvT0aD qSFob2Uc4gAK6koN71HcBfERwR358CJyuUtPRanw3uum0WVCifXNSp+Hy c=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="207883460" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-iad-1a-828bd003.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-33001.sea14.amazon.com with ESMTP; 06 Jul 2022 23:41:10 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1a-828bd003.us-east-1.amazon.com (Postfix) with ESMTPS id 90205810FC; Wed, 6 Jul 2022 23:41:06 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:41:05 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:41:02 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , , Subash Abhinov Kasiviswanathan Subject: [PATCH v2 net 02/12] sysctl: Fix data races in proc_douintvec(). Date: Wed, 6 Jul 2022 16:39:53 -0700 Message-ID: <20220706234003.66760-3-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch changes proc_douintvec() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_douintvec() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side. Fixes: e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields") Signed-off-by: Kuniyuki Iwashima --- CC: Subash Abhinov Kasiviswanathan --- kernel/sysctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c8a05655ae60..2ab8c2a37e8f 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -472,9 +472,9 @@ static int do_proc_douintvec_conv(unsigned long *lvalp, if (write) { if (*lvalp > UINT_MAX) return -EINVAL; - *valp = *lvalp; + WRITE_ONCE(*valp, *lvalp); } else { - unsigned int val = *valp; + unsigned int val = READ_ONCE(*valp); *lvalp = (unsigned long)val; } return 0; From patchwork Wed Jul 6 23:39:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908909 X-Patchwork-Delegate: kuba@kernel.org 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 70604C433EF for ; Wed, 6 Jul 2022 23:41:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234723AbiGFXld (ORCPT ); Wed, 6 Jul 2022 19:41:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234766AbiGFXl2 (ORCPT ); Wed, 6 Jul 2022 19:41:28 -0400 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A2F92CE13; Wed, 6 Jul 2022 16:41:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150886; x=1688686886; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=0f2zEj2TEAcaxLiz0mal5HBwzbaZDgnc95s1L0ryEyM=; b=N05iY0oPV5oq1qgWict6KAcrCzZ21hfbeDbKSk0JG3N6bMbD9MlsMUTZ Wh/oN6NiNbwK9NE2oOBmvDhDV0efRjZu7k2AlSAnuci/95V6NCghktsdD U6a7rmKkPM/DaE6EJSiM/OripQiyE5qG6Jd+tWydG6sS1QpTQxdWFZPMk E=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="235612750" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1a-87b71607.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP; 06 Jul 2022 23:41:25 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1a-87b71607.us-east-1.amazon.com (Postfix) with ESMTPS id 8CF4C141001; Wed, 6 Jul 2022 23:41:21 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:41:20 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:41:17 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 03/12] sysctl: Fix data races in proc_dointvec_minmax(). Date: Wed, 6 Jul 2022 16:39:54 -0700 Message-ID: <20220706234003.66760-4-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch changes proc_dointvec_minmax() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_dointvec_minmax() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 2ab8c2a37e8f..4d87832367f2 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -857,7 +857,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, if ((param->min && *param->min > tmp) || (param->max && *param->max < tmp)) return -EINVAL; - *valp = tmp; + WRITE_ONCE(*valp, tmp); } return 0; From patchwork Wed Jul 6 23:39:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908910 X-Patchwork-Delegate: kuba@kernel.org 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 15F7AC433EF for ; Wed, 6 Jul 2022 23:42:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234819AbiGFXmB (ORCPT ); Wed, 6 Jul 2022 19:42:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234777AbiGFXlu (ORCPT ); Wed, 6 Jul 2022 19:41:50 -0400 Received: from smtp-fw-6001.amazon.com (smtp-fw-6001.amazon.com [52.95.48.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CD262CE26; Wed, 6 Jul 2022 16:41:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150910; x=1688686910; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=/M11D+ZL2bejtlLvWMmLudSrsjwDj6P5JFV1eyWk4mc=; b=uvVUT/16UJD/CFq7vv1gPe7TksAY3tAXcFpoUEqDfw4inMA4dHmUv4PH IRBKMhCIscsA602kWAmEgEgEZd6MG1TzmIJOIH1KNDXp4M8a9/zqKw6nv C8vUlXYeNuY7IMizYnGTTEtze/Z6pYrYYHK26EQon1wtHYqLS2I+9G3kF Y=; Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-iad-1e-54c9d11f.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-6001.iad6.amazon.com with ESMTP; 06 Jul 2022 23:41:38 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1e-54c9d11f.us-east-1.amazon.com (Postfix) with ESMTPS id 68FFBC08C1; Wed, 6 Jul 2022 23:41:35 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:41:34 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:41:31 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 04/12] sysctl: Fix data races in proc_douintvec_minmax(). Date: Wed, 6 Jul 2022 16:39:55 -0700 Message-ID: <20220706234003.66760-5-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch changes proc_douintvec_minmax() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_douintvec_minmax() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side. Fixes: 61d9b56a8920 ("sysctl: add unsigned int range support") Signed-off-by: Kuniyuki Iwashima --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 4d87832367f2..379721a03d41 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -923,7 +923,7 @@ static int do_proc_douintvec_minmax_conv(unsigned long *lvalp, (param->max && *param->max < tmp)) return -ERANGE; - *valp = tmp; + WRITE_ONCE(*valp, tmp); } return 0; From patchwork Wed Jul 6 23:39:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908911 X-Patchwork-Delegate: kuba@kernel.org 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 B32BAC43334 for ; Wed, 6 Jul 2022 23:42:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234829AbiGFXmD (ORCPT ); Wed, 6 Jul 2022 19:42:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234795AbiGFXlz (ORCPT ); Wed, 6 Jul 2022 19:41:55 -0400 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C63F22CDF8; Wed, 6 Jul 2022 16:41:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150915; x=1688686915; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GD/OFG/lYqP+3LBBqBX1zYuBJC2S2pBdMallmmNdNks=; b=YQWCTdiJemr/w+UVvVFlqv8YSVnJPeqSyyNX0mVmuZo5FjdIpJtq3vm0 UyCe3uwk/U+961iF9aKjkVIMJBYVxr0Xt5yp1qCbOoOOd7p8v9WQ0Q0OI D7lTrQ3uwtInmOQUHwSDmqJxOD5ORLwN8hVeHAEejFBkAKEdwA9VxYX5f U=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="235612823" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1a-b09d0114.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP; 06 Jul 2022 23:41:54 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1a-b09d0114.us-east-1.amazon.com (Postfix) with ESMTPS id D42D9813CD; Wed, 6 Jul 2022 23:41:50 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:41:50 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:41:47 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 05/12] sysctl: Fix data races in proc_doulongvec_minmax(). Date: Wed, 6 Jul 2022 16:39:56 -0700 Message-ID: <20220706234003.66760-6-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch changes proc_doulongvec_minmax() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_doulongvec_minmax() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- kernel/sysctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 379721a03d41..8c55ba01f41b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1090,9 +1090,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, err = -EINVAL; break; } - *i = val; + WRITE_ONCE(*i, val); } else { - val = convdiv * (*i) / convmul; + val = convdiv * READ_ONCE(*i) / convmul; if (!first) proc_put_char(&buffer, &left, '\t'); proc_put_long(&buffer, &left, val, false); From patchwork Wed Jul 6 23:39:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908912 X-Patchwork-Delegate: kuba@kernel.org 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 C3DEBCCA480 for ; Wed, 6 Jul 2022 23:42:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234184AbiGFXmy (ORCPT ); Wed, 6 Jul 2022 19:42:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234870AbiGFXmO (ORCPT ); Wed, 6 Jul 2022 19:42:14 -0400 Received: from smtp-fw-6001.amazon.com (smtp-fw-6001.amazon.com [52.95.48.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D28E2DA83; Wed, 6 Jul 2022 16:42:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150929; x=1688686929; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YKlh3xU99+PnvB8tm4pVIMQEaPxMo6bcMnrjqauDi48=; b=BZ57ceqbL7CzekeOmV5oMc3mER3nSQxqoUSTVHBcy7bgFLyI0EPHqr6I Rth7rv0wsAw2wJae/s3B/VbAaDxwlKFJxtolKszErOPc7stSyX/VU82r7 2rhGjTw8QOM4lSkzuwioYkkYonLNoCmN1LFjgMRIAuHJ4HARjPPisGlgA A=; Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-iad-1e-f771ae83.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-6001.iad6.amazon.com with ESMTP; 06 Jul 2022 23:42:08 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1e-f771ae83.us-east-1.amazon.com (Postfix) with ESMTPS id 519F81216E0; Wed, 6 Jul 2022 23:42:05 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:42:04 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:42:01 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 06/12] sysctl: Fix data races in proc_dointvec_jiffies(). Date: Wed, 6 Jul 2022 16:39:57 -0700 Message-ID: <20220706234003.66760-7-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch changes proc_dointvec_jiffies() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_dointvec_jiffies() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- kernel/sysctl.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8c55ba01f41b..bf9383d17e1b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1173,9 +1173,12 @@ static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp, if (write) { if (*lvalp > INT_MAX / HZ) return 1; - *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ); + if (*negp) + WRITE_ONCE(*valp, -*lvalp * HZ); + else + WRITE_ONCE(*valp, *lvalp * HZ); } else { - int val = *valp; + int val = READ_ONCE(*valp); unsigned long lval; if (val < 0) { *negp = true; From patchwork Wed Jul 6 23:39:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908913 X-Patchwork-Delegate: kuba@kernel.org 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 969A2CCA482 for ; Wed, 6 Jul 2022 23:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234762AbiGFXmz (ORCPT ); Wed, 6 Jul 2022 19:42:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234958AbiGFXml (ORCPT ); Wed, 6 Jul 2022 19:42:41 -0400 Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2A392CE05; Wed, 6 Jul 2022 16:42:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150960; x=1688686960; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=WrRefD5BgkzIzv5gXe6/gL75Imx09IKo5AaSxIEliV4=; b=PwlIbTlzCepYu3l/LGa8ey873Y0dgDJ9XSwX+E/g5m8PEL7tYKrMqOdX ooAIFfBiOMmyHClQocRBvqcQElxK9Lz+kI7CiJqP4lX4dMjGDs3EJf9h1 K8jWWxIXjE8bmKMI4GcMyFLGuKmnbvVq2GQ6QslmI87lpS0cAyGPHnzQ5 8=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="105640207" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-iad-1a-c92fe759.us-east-1.amazon.com) ([10.25.36.214]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP; 06 Jul 2022 23:42:23 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1a-c92fe759.us-east-1.amazon.com (Postfix) with ESMTPS id 9B400C0846; Wed, 6 Jul 2022 23:42:20 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:42:19 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:42:16 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 07/12] tcp: Fix a data-race around sysctl_tcp_max_orphans. Date: Wed, 6 Jul 2022 16:39:58 -0700 Message-ID: <20220706234003.66760-8-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading sysctl_tcp_max_orphans, it can be changed concurrently. So, we need to add READ_ONCE() to avoid a data-race. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- net/ipv4/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 028513d3e2a2..2222dfdde316 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2715,7 +2715,8 @@ static void tcp_orphan_update(struct timer_list *unused) static bool tcp_too_many_orphans(int shift) { - return READ_ONCE(tcp_orphan_cache) << shift > sysctl_tcp_max_orphans; + return READ_ONCE(tcp_orphan_cache) << shift > + READ_ONCE(sysctl_tcp_max_orphans); } bool tcp_check_oom(struct sock *sk, int shift) From patchwork Wed Jul 6 23:39:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908914 X-Patchwork-Delegate: kuba@kernel.org 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 E1896C433EF for ; Wed, 6 Jul 2022 23:42:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234779AbiGFXm4 (ORCPT ); Wed, 6 Jul 2022 19:42:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234956AbiGFXmk (ORCPT ); Wed, 6 Jul 2022 19:42:40 -0400 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBFDF2CE0C; Wed, 6 Jul 2022 16:42:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150960; x=1688686960; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TlBSe1T/jB+nq/KU9u+Is0f8lN4V4SAmfBQAgoWCtoM=; b=TZ4cbHESyvdIsGxPBdc1TgKDRcnxjC0O962TKhmi0UykBn3XnxYh+D8b 5oxpKYGQ66lR1JZZOT3PB/orCEBwEt4MuogVtHU625Ba/ejWuekUCbxH9 gYNdzsyxGEVh2aBK0tvE7i7c9ewQHGmzeNAzsdTkzuvHSr2g7PtSY4EGs E=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="235612951" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1e-f771ae83.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP; 06 Jul 2022 23:42:38 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1e-f771ae83.us-east-1.amazon.com (Postfix) with ESMTPS id 7A7171216DF; Wed, 6 Jul 2022 23:42:35 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:42:34 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:42:31 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 08/12] inetpeer: Fix data-races around sysctl. Date: Wed, 6 Jul 2022 16:39:59 -0700 Message-ID: <20220706234003.66760-9-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading inetpeer sysctl variables, they can be changed concurrently. So, we need to add READ_ONCE() to avoid data-races. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- net/ipv4/inetpeer.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c index da21dfce24d7..e9fed83e9b3c 100644 --- a/net/ipv4/inetpeer.c +++ b/net/ipv4/inetpeer.c @@ -141,16 +141,20 @@ static void inet_peer_gc(struct inet_peer_base *base, struct inet_peer *gc_stack[], unsigned int gc_cnt) { + int peer_threshold, peer_maxttl, peer_minttl; struct inet_peer *p; __u32 delta, ttl; int i; - if (base->total >= inet_peer_threshold) + peer_threshold = READ_ONCE(inet_peer_threshold); + peer_maxttl = READ_ONCE(inet_peer_maxttl); + peer_minttl = READ_ONCE(inet_peer_minttl); + + if (base->total >= peer_threshold) ttl = 0; /* be aggressive */ else - ttl = inet_peer_maxttl - - (inet_peer_maxttl - inet_peer_minttl) / HZ * - base->total / inet_peer_threshold * HZ; + ttl = peer_maxttl - (peer_maxttl - peer_minttl) / HZ * + base->total / peer_threshold * HZ; for (i = 0; i < gc_cnt; i++) { p = gc_stack[i]; From patchwork Wed Jul 6 23:40:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908915 X-Patchwork-Delegate: kuba@kernel.org 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 8FD95C433EF for ; Wed, 6 Jul 2022 23:43:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234834AbiGFXnG (ORCPT ); Wed, 6 Jul 2022 19:43:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234766AbiGFXmz (ORCPT ); Wed, 6 Jul 2022 19:42:55 -0400 Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01AE02CE0C; Wed, 6 Jul 2022 16:42:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150975; x=1688686975; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Mb8bykoh05TnFu3klpij8rmO7boyb5CxKa4HMwXdVPE=; b=XDakLcPVh0ZWHujBPnVneyCvPuIInRjIrtkuiPndjtU/I/QMAJ4LlJqm HR9cxPOYYbkdgIIv8D++eUvuiBmT1SUnBtcdkJ0VyShtoLMX4OZ2GQVFi nXgvXZSsR62fEMnIqot9scub3z7vrWL/jke59aFsIDyXZO2qjJ50TgiMl 8=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="105640317" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-iad-1a-4ba5c7da.us-east-1.amazon.com) ([10.25.36.214]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP; 06 Jul 2022 23:42:53 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1a-4ba5c7da.us-east-1.amazon.com (Postfix) with ESMTPS id 1F28C8FB5D; Wed, 6 Jul 2022 23:42:50 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:42:50 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:42:47 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 09/12] net: Fix data-races around sysctl_mem. Date: Wed, 6 Jul 2022 16:40:00 -0700 Message-ID: <20220706234003.66760-10-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading .sysctl_mem, it can be changed concurrently. So, we need to add READ_ONCE() to avoid data-races. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- include/net/sock.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/sock.h b/include/net/sock.h index 72ca97ccb460..9fa54762e077 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1529,7 +1529,7 @@ void __sk_mem_reclaim(struct sock *sk, int amount); /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */ static inline long sk_prot_mem_limits(const struct sock *sk, int index) { - long val = sk->sk_prot->sysctl_mem[index]; + long val = READ_ONCE(sk->sk_prot->sysctl_mem[index]); #if PAGE_SIZE > SK_MEM_QUANTUM val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT; From patchwork Wed Jul 6 23:40:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908916 X-Patchwork-Delegate: kuba@kernel.org 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 771EEC433EF for ; Wed, 6 Jul 2022 23:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234823AbiGFXnh (ORCPT ); Wed, 6 Jul 2022 19:43:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234853AbiGFXn0 (ORCPT ); Wed, 6 Jul 2022 19:43:26 -0400 Received: from smtp-fw-6002.amazon.com (smtp-fw-6002.amazon.com [52.95.49.90]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB1A42D1CE; Wed, 6 Jul 2022 16:43:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657151000; x=1688687000; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dZbdEudaqSAgySwZHwP+NdzQ1K6SO28Of0fID5u9j00=; b=KTtPl9e4bcMRFAtKPE1G1QN73dGyXaLF+letTw+f2WKieCosw6YJW9qz b6Zt2yiiV/9FYNQ8GZ0a+a5AQDDNvfuP5My3Wlzeu6SrWsFPAfXTjofR7 w5CKIgrmAOSY3vVayaEQX11vR8k9sRfRcKj+8997DZsT/r85yk4ni0SSW k=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="218850523" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-iad-1e-8be8ed69.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-6002.iad6.amazon.com with ESMTP; 06 Jul 2022 23:43:09 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1e-8be8ed69.us-east-1.amazon.com (Postfix) with ESMTPS id 0E6E3C0881; Wed, 6 Jul 2022 23:43:05 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:43:05 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:43:02 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , , Paul Moore Subject: [PATCH v2 net 10/12] cipso: Fix data-races around sysctl. Date: Wed, 6 Jul 2022 16:40:01 -0700 Message-ID: <20220706234003.66760-11-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading cipso sysctl variables, they can be changed concurrently. So, we need to add READ_ONCE() to avoid data-races. Fixes: 446fda4f2682 ("[NetLabel]: CIPSOv4 engine") Signed-off-by: Kuniyuki Iwashima Acked-by: Paul Moore --- CC: Paul Moore --- Documentation/networking/ip-sysctl.rst | 2 +- net/ipv4/cipso_ipv4.c | 12 +++++++----- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 9f41961d11d5..0e58001f8580 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -1085,7 +1085,7 @@ cipso_cache_enable - BOOLEAN cipso_cache_bucket_size - INTEGER The CIPSO label cache consists of a fixed size hash table with each hash bucket containing a number of cache entries. This variable limits - the number of entries in each hash bucket; the larger the value the + the number of entries in each hash bucket; the larger the value is, the more CIPSO label mappings that can be cached. When the number of entries in a given hash bucket reaches this limit adding new entries causes the oldest entry in the bucket to be removed to make room. diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 62d5f99760aa..6cd3b6c559f0 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -239,7 +239,7 @@ static int cipso_v4_cache_check(const unsigned char *key, struct cipso_v4_map_cache_entry *prev_entry = NULL; u32 hash; - if (!cipso_v4_cache_enabled) + if (!READ_ONCE(cipso_v4_cache_enabled)) return -ENOENT; hash = cipso_v4_map_cache_hash(key, key_len); @@ -296,13 +296,14 @@ static int cipso_v4_cache_check(const unsigned char *key, int cipso_v4_cache_add(const unsigned char *cipso_ptr, const struct netlbl_lsm_secattr *secattr) { + int bkt_size = READ_ONCE(cipso_v4_cache_bucketsize); int ret_val = -EPERM; u32 bkt; struct cipso_v4_map_cache_entry *entry = NULL; struct cipso_v4_map_cache_entry *old_entry = NULL; u32 cipso_ptr_len; - if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0) + if (!READ_ONCE(cipso_v4_cache_enabled) || bkt_size <= 0) return 0; cipso_ptr_len = cipso_ptr[1]; @@ -322,7 +323,7 @@ int cipso_v4_cache_add(const unsigned char *cipso_ptr, bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1); spin_lock_bh(&cipso_v4_cache[bkt].lock); - if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) { + if (cipso_v4_cache[bkt].size < bkt_size) { list_add(&entry->list, &cipso_v4_cache[bkt].list); cipso_v4_cache[bkt].size += 1; } else { @@ -1199,7 +1200,8 @@ static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def, /* This will send packets using the "optimized" format when * possible as specified in section 3.4.2.6 of the * CIPSO draft. */ - if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10) + if (READ_ONCE(cipso_v4_rbm_optfmt) && ret_val > 0 && + ret_val <= 10) tag_len = 14; else tag_len = 4 + ret_val; @@ -1603,7 +1605,7 @@ int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option) * all the CIPSO validations here but it doesn't * really specify _exactly_ what we need to validate * ... so, just make it a sysctl tunable. */ - if (cipso_v4_rbm_strictvalid) { + if (READ_ONCE(cipso_v4_rbm_strictvalid)) { if (cipso_v4_map_lvl_valid(doi_def, tag[3]) < 0) { err_offset = opt_iter + 3; From patchwork Wed Jul 6 23:40:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908918 X-Patchwork-Delegate: kuba@kernel.org 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 A967FC43334 for ; Wed, 6 Jul 2022 23:43:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234851AbiGFXny (ORCPT ); Wed, 6 Jul 2022 19:43:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234849AbiGFXnl (ORCPT ); Wed, 6 Jul 2022 19:43:41 -0400 Received: from smtp-fw-80006.amazon.com (smtp-fw-80006.amazon.com [99.78.197.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BD4F2D1E3; Wed, 6 Jul 2022 16:43:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657151021; x=1688687021; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=AvvrK8qrOu12cbubhLZfU/X+OByykQFjHxBineAuT5M=; b=iOcUqYCBYRxd8ja/YLdzrDQXe95nZnPTvTuCDNLXg30Kuj1gnbYUelqD GCVhf40ywLRRJv89WeVv3NF2pxHSRF2/GdmxjC9oFHMIIOB893Z+iAP13 ADn1dDxPSWMjWhcbp4B9SnwgDsApD5L960EIn8bMe/JM+35JFnveMXiX4 U=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="105569596" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1d-7a21ed79.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-80006.pdx80.corp.amazon.com with ESMTP; 06 Jul 2022 23:43:24 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1d-7a21ed79.us-east-1.amazon.com (Postfix) with ESMTPS id C335222015B; Wed, 6 Jul 2022 23:43:20 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:43:19 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:43:16 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 11/12] icmp: Fix data-races around sysctl. Date: Wed, 6 Jul 2022 16:40:02 -0700 Message-ID: <20220706234003.66760-12-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading icmp sysctl variables, they can be changed concurrently. So, we need to add READ_ONCE() to avoid data-races. Fixes: 4cdf507d5452 ("icmp: add a global rate limitation") Signed-off-by: Kuniyuki Iwashima --- net/ipv4/icmp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index efea0e796f06..0f9e61d29f73 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -253,11 +253,12 @@ bool icmp_global_allow(void) spin_lock(&icmp_global.lock); delta = min_t(u32, now - icmp_global.stamp, HZ); if (delta >= HZ / 50) { - incr = sysctl_icmp_msgs_per_sec * delta / HZ ; + incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; if (incr) WRITE_ONCE(icmp_global.stamp, now); } - credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst); + credit = min_t(u32, icmp_global.credit + incr, + READ_ONCE(sysctl_icmp_msgs_burst)); if (credit) { /* We want to use a credit of one in average, but need to randomize * it for security reasons. From patchwork Wed Jul 6 23:40:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908917 X-Patchwork-Delegate: kuba@kernel.org 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 3F119C433EF for ; Wed, 6 Jul 2022 23:43:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234102AbiGFXnw (ORCPT ); Wed, 6 Jul 2022 19:43:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234852AbiGFXnm (ORCPT ); Wed, 6 Jul 2022 19:43:42 -0400 Received: from smtp-fw-6001.amazon.com (smtp-fw-6001.amazon.com [52.95.48.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B8792D1C5; Wed, 6 Jul 2022 16:43:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657151021; x=1688687021; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=gTSC9dkHnErNPeQoDYC86G80+g9Bjz1N0PmHh2qX/hI=; b=va/p6SB0UvtgxIrhBHDizX12KqKIjN0ncHUEfHGpAyQ8UWZNI3+r06cb wJIvkoT+Qq4Q0iLxMya5relNPv8KiDOHbGbtNK2etIwao9w3oKYSYMgYC i3gdab+3osOV57ZfIbwyPktL7NNo5OxEH6d60rghfSxyNtJ8FUDSaG64E 0=; Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-iad-1a-b27d4a00.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-6001.iad6.amazon.com with ESMTP; 06 Jul 2022 23:43:39 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1a-b27d4a00.us-east-1.amazon.com (Postfix) with ESMTPS id 04F33811CF; Wed, 6 Jul 2022 23:43:35 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 6 Jul 2022 23:43:35 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 6 Jul 2022 23:43:31 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , , David Ahern Subject: [PATCH v2 net 12/12] ipv4: Fix a data-race around sysctl_fib_sync_mem. Date: Wed, 6 Jul 2022 16:40:03 -0700 Message-ID: <20220706234003.66760-13-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading sysctl_fib_sync_mem, it can be changed concurrently. So, we need to add READ_ONCE() to avoid a data-race. Fixes: 9ab948a91b2c ("ipv4: Allow amount of dirty memory from fib resizing to be controllable") Signed-off-by: Kuniyuki Iwashima --- CC: David Ahern --- net/ipv4/fib_trie.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 2734c3af7e24..46e8a5125853 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -498,7 +498,7 @@ static void tnode_free(struct key_vector *tn) tn = container_of(head, struct tnode, rcu)->kv; } - if (tnode_free_size >= sysctl_fib_sync_mem) { + if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) { tnode_free_size = 0; synchronize_rcu(); }