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 2D9671ED38 for ; Tue, 25 Jul 2023 11:34:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AC64C433C7; Tue, 25 Jul 2023 11:34:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690284858; bh=CAJSx9j07tToZ5MsAHaJht0zx8/+3tSuR4sHHb1lI/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A4hOHZyl+HqmnMs7MDCfKJVj3vIE9qHY8L1qOuUu0n7K6XaIYP1vtKxEXIyxd5vcA oCUotbr2FQOAAevg+iiAmx7krbUjgchd9orhlm5pxw22YWZbN+AXOGq0pHkJRS2bRi LEMHw1VB2fXzSgWC3Psfraxt5/aTQNQKluEVW1QU= 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 5.10 499/509] tcp: annotate data-races around icsk->icsk_syn_retries Date: Tue, 25 Jul 2023 12:47:18 +0200 Message-ID: <20230725104616.596122036@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 3a037f0f3c4bfe44518f2fbb478aa2f99a9cd8bb ] do_tcp_getsockopt() and reqsk_timer_handler() read icsk->icsk_syn_retries 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/20230719212857.3943972-7-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/inet_connection_sock.c | 2 +- net/ipv4/tcp.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index dfea3088bc7e9..5f71a1c74e7e0 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -740,7 +740,7 @@ static void reqsk_timer_handler(struct timer_list *t) if (inet_sk_state_load(sk_listener) != TCP_LISTEN) goto drop; - max_syn_ack_retries = icsk->icsk_syn_retries ? : + max_syn_ack_retries = READ_ONCE(icsk->icsk_syn_retries) ? : READ_ONCE(net->ipv4.sysctl_tcp_synack_retries); /* Normally all the openreqs are young and become mature * (i.e. converted to established socket) for first timeout. diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index fc4d560909b50..e172348fc5c61 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3072,7 +3072,7 @@ int tcp_sock_set_syncnt(struct sock *sk, int val) return -EINVAL; lock_sock(sk); - inet_csk(sk)->icsk_syn_retries = val; + WRITE_ONCE(inet_csk(sk)->icsk_syn_retries, val); release_sock(sk); return 0; } @@ -3337,7 +3337,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, if (val < 1 || val > MAX_TCP_SYNCNT) err = -EINVAL; else - icsk->icsk_syn_retries = val; + WRITE_ONCE(icsk->icsk_syn_retries, val); break; case TCP_SAVE_SYN: @@ -3743,7 +3743,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = keepalive_probes(tp); break; case TCP_SYNCNT: - val = icsk->icsk_syn_retries ? : + val = READ_ONCE(icsk->icsk_syn_retries) ? : READ_ONCE(net->ipv4.sysctl_tcp_syn_retries); break; case TCP_LINGER2: -- 2.39.2