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 C5A35C0015E for ; Tue, 25 Jul 2023 11:01:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233842AbjGYLA7 (ORCPT ); Tue, 25 Jul 2023 07:00:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233843AbjGYLAc (ORCPT ); Tue, 25 Jul 2023 07:00:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9126B448A for ; Tue, 25 Jul 2023 03:57:48 -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 2FF5E61656 for ; Tue, 25 Jul 2023 10:57:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 400E0C433C7; Tue, 25 Jul 2023 10:57:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690282667; bh=kWMhUMf90TqnTj/EABY9rEBxF+Zy7P3ZVcUlSLokWws=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fyah6WBWnZ/fn6QI1JHDbM0nu48lBa8CRn1pdTjrcqom7vJazPV2nNVNq/NXlRqVB mWyF+mA1aAuGXpWABiJVRz1dpzgx1GMhFFj4TUe8M3/tZvt+gEAN9pg8I9k16kR8AE kCnAk9aflUvT11SlU4Dwgkf1zmGIEsaJRtitqZLw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.4 211/227] tcp: annotate data-races around tp->keepalive_probes Date: Tue, 25 Jul 2023 12:46:18 +0200 Message-ID: <20230725104523.497001373@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104514.821564989@linuxfoundation.org> References: <20230725104514.821564989@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 6e5e1de616bf5f3df1769abc9292191dfad9110a ] do_tcp_getsockopt() reads tp->keepalive_probes while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-6-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/tcp.h | 9 +++++++-- net/ipv4/tcp.c | 5 +++-- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 45d50a40795da..f5c20afab6286 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1538,9 +1538,14 @@ static inline int keepalive_time_when(const struct tcp_sock *tp) static inline int keepalive_probes(const struct tcp_sock *tp) { struct net *net = sock_net((struct sock *)tp); + int val; + + /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() + * and do_tcp_setsockopt(). + */ + val = READ_ONCE(tp->keepalive_probes); - return tp->keepalive_probes ? : - READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); + return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); } static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 514817119bd4d..cc7966cfad1a3 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3466,7 +3466,8 @@ int tcp_sock_set_keepcnt(struct sock *sk, int val) return -EINVAL; lock_sock(sk); - tcp_sk(sk)->keepalive_probes = val; + /* Paired with READ_ONCE() in keepalive_probes() */ + WRITE_ONCE(tcp_sk(sk)->keepalive_probes, val); release_sock(sk); return 0; } @@ -3674,7 +3675,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, if (val < 1 || val > MAX_TCP_KEEPCNT) err = -EINVAL; else - tp->keepalive_probes = val; + WRITE_ONCE(tp->keepalive_probes, val); break; case TCP_SYNCNT: if (val < 1 || val > MAX_TCP_SYNCNT) -- 2.39.2