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 18269C433EF for ; Tue, 19 Jul 2022 12:13:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238869AbiGSMNa (ORCPT ); Tue, 19 Jul 2022 08:13:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238919AbiGSMMh (ORCPT ); Tue, 19 Jul 2022 08:12:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48F1952DF7; Tue, 19 Jul 2022 05:03:51 -0700 (PDT) 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 4B2306171F; Tue, 19 Jul 2022 12:03:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F3EFC341C6; Tue, 19 Jul 2022 12:03:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658232230; bh=uVoT/5u5HAXi7mBTKdcbZJAAIrh99J+aHCAY23AI2eA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wRNkK1zp0buizbjk/OiyfCU8uaWZhSSbcm+VIm3Kid8z5n75rxSiL9EwK4QNx54s6 etDAF8bwEuU1D4EyTcOpzmK40QNchwxnM/FQsBvekWiH+7VIfTlyNAFj0zv1LI5Nh9 KOaESD9eT/Vxh8+tgUjM4tKeN/LOvUOQLncjeG1U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 29/71] icmp: Fix data-races around sysctl. Date: Tue, 19 Jul 2022 13:53:52 +0200 Message-Id: <20220719114555.163037962@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220719114552.477018590@linuxfoundation.org> References: <20220719114552.477018590@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 48d7ee321ea5182c6a70782aa186422a70e67e22 ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 f86f948a4b4c..a590ff81e5f8 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -261,11 +261,12 @@ 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. -- 2.35.1