From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 135DC1ED38 for ; Tue, 25 Jul 2023 11:33:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38227C433C9; Tue, 25 Jul 2023 11:33:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690284827; bh=W1T4xNzQjq+//7YpZzt1ubp5OTfzs7CTPWouUfPz5us=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nRhU1jPibKPyhL0uZFocB69EfVvGQzJsIvwYnR9Ha2DRLFr1kK11DRSPWqcfZGuAO 6DNmTSuQdcyv/BCn0MDWhkH/b2UQSGfLdVILbVLLvZYsaQdeGT0MNrSxixfRXVVI3+ z2Dke5wNmDeXfBJwC8W0Yhm2PN8XLvDew+2N2iC0= 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 5.10 495/509] tcp: annotate data-races around tp->keepalive_intvl Date: Tue, 25 Jul 2023 12:47:14 +0200 Message-ID: <20230725104616.421846207@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104553.588743331@linuxfoundation.org> References: <20230725104553.588743331@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit 5ecf9d4f52ff2f1d4d44c9b68bc75688e82f13b4 ] do_tcp_getsockopt() reads tp->keepalive_intvl 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/20230719212857.3943972-5-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/tcp.h | 9 +++++++-- net/ipv4/tcp.c | 4 ++-- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 92de7c049f19e..428f84f6e0d0c 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1451,9 +1451,14 @@ void tcp_leave_memory_pressure(struct sock *sk); static inline int keepalive_intvl_when(const struct tcp_sock *tp) { struct net *net = sock_net((struct sock *)tp); + int val; + + /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() + * and do_tcp_setsockopt(). + */ + val = READ_ONCE(tp->keepalive_intvl); - return tp->keepalive_intvl ? : - READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); + return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); } static inline int keepalive_time_when(const struct tcp_sock *tp) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 053e4880d8f0f..b5a05b0984146 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3126,7 +3126,7 @@ int tcp_sock_set_keepintvl(struct sock *sk, int val) return -EINVAL; lock_sock(sk); - tcp_sk(sk)->keepalive_intvl = val * HZ; + WRITE_ONCE(tcp_sk(sk)->keepalive_intvl, val * HZ); release_sock(sk); return 0; } @@ -3324,7 +3324,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, if (val < 1 || val > MAX_TCP_KEEPINTVL) err = -EINVAL; else - tp->keepalive_intvl = val * HZ; + WRITE_ONCE(tp->keepalive_intvl, val * HZ); break; case TCP_KEEPCNT: if (val < 1 || val > MAX_TCP_KEEPCNT) -- 2.39.2