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 3A67F1EA7E for ; Tue, 25 Jul 2023 11:10:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1DE2C433C7; Tue, 25 Jul 2023 11:10:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690283417; bh=+6aTzBbfZvzgvnTZ/zjebS3a3ELsuymSrxzF/L+okDs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1Vbbsv/7bSG/DWGoP/MUfd4qWUA5WzSYkWJG78+EUJUAJuvTOPW+Ky9ZkggQDr1Za i0KWExGN8SDNqtmf94P7Icqd23cjZ8zIW/FKjIuVM32Ltk1fNz8ShsSL4lzZzPqjVh h/KaDBR//cZOEvIMGk+zunVatwe278ZX449EKq3E= 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 5.15 69/78] tcp: annotate data-races around icsk->icsk_syn_retries Date: Tue, 25 Jul 2023 12:47:00 +0200 Message-ID: <20230725104453.951944352@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104451.275227789@linuxfoundation.org> References: <20230725104451.275227789@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 4fb0506430774..c770719797e12 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -833,7 +833,7 @@ static void reqsk_timer_handler(struct timer_list *t) icsk = inet_csk(sk_listener); net = sock_net(sk_listener); - 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 994ac3cd50e1d..4077b456e3838 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3296,7 +3296,7 @@ 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; } @@ -3577,7 +3577,7 @@ 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: @@ -3991,7 +3991,7 @@ 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