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 0C176C001B0 for ; Wed, 9 Aug 2023 11:30:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233862AbjHILaz (ORCPT ); Wed, 9 Aug 2023 07:30:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233866AbjHILay (ORCPT ); Wed, 9 Aug 2023 07:30:54 -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 53252172A for ; Wed, 9 Aug 2023 04:30:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DD1816338B for ; Wed, 9 Aug 2023 11:30:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E92CFC433C8; Wed, 9 Aug 2023 11:30:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691580653; bh=f45O86Cx/AR9G7cJfPcNgmdNfX8pxWJAn6MY+EoqXjw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1QC2WzYz+kub+21n9Oe3SwDggawA+Unrh2pYmbVBbYKVLHZkNIbjf7t9YUgrq8sn5 UJnB2LEg+9O/lCiVs2aMpzOh0J5RC0HH2zkfGV+6GgI5zWZAGHAGk/M6vV25g1OUOh q9vNKJLznfBfHcbA5seq3c314wtWz2sI/5D0vjUA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 101/154] net: annotate data-races around sk->sk_max_pacing_rate Date: Wed, 9 Aug 2023 12:42:12 +0200 Message-ID: <20230809103640.313066931@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103636.887175326@linuxfoundation.org> References: <20230809103636.887175326@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit ea7f45ef77b39e72244d282e47f6cb1ef4135cd2 ] sk_getsockopt() runs locklessly. This means sk->sk_max_pacing_rate can be read while other threads are changing its value. Fixes: 62748f32d501 ("net: introduce SO_MAX_PACING_RATE") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/sock.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index d55eea5538bce..539c39ad1e488 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1117,7 +1117,8 @@ int sock_setsockopt(struct socket *sock, int level, int optname, cmpxchg(&sk->sk_pacing_status, SK_PACING_NONE, SK_PACING_NEEDED); - sk->sk_max_pacing_rate = ulval; + /* Pairs with READ_ONCE() from sk_getsockopt() */ + WRITE_ONCE(sk->sk_max_pacing_rate, ulval); sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval); break; } @@ -1478,12 +1479,14 @@ int sock_getsockopt(struct socket *sock, int level, int optname, #endif case SO_MAX_PACING_RATE: + /* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */ if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) { lv = sizeof(v.ulval); - v.ulval = sk->sk_max_pacing_rate; + v.ulval = READ_ONCE(sk->sk_max_pacing_rate); } else { /* 32bit version */ - v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U); + v.val = min_t(unsigned long, ~0U, + READ_ONCE(sk->sk_max_pacing_rate)); } break; -- 2.40.1