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.