From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hangbin Liu Subject: [PATCH net] tcp: init tcp_options before using it. Date: Mon, 8 May 2017 17:57:57 +0800 Message-ID: <1494237477-19023-1-git-send-email-liuhangbin@gmail.com> Cc: Hangbin Liu To: netdev@vger.kernel.org Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:35854 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753808AbdEHJ6R (ORCPT ); Mon, 8 May 2017 05:58:17 -0400 Received: by mail-pf0-f195.google.com with SMTP id v14so9184201pfd.3 for ; Mon, 08 May 2017 02:58:17 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: I searched 4308fc58dced ("tcp: Document use of undefined variable") in archive list, but did not find the thread. So I'm not sure why we only add a description about un-initialized value. Even we don't use tmp_opt.sack_ok, I think it would be more safe to initialize the value before using it. Just as other caller did. Signed-off-by: Hangbin Liu --- net/ipv4/tcp_minisocks.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 717be4d..6ca2546 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -85,8 +85,6 @@ tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw, * spinlock it. I do not want! Well, probability of misbehaviour * is ridiculously low and, seems, we could use some mb() tricks * to avoid misread sequence numbers, states etc. --ANK - * - * We don't need to initialize tmp_out.sack_ok as we don't use the results */ enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, @@ -96,7 +94,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw); bool paws_reject = false; - tmp_opt.saw_tstamp = 0; + memset(&tmp_opt, 0, sizeof(tmp_opt)); if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) { tcp_parse_options(skb, &tmp_opt, 0, NULL); @@ -542,8 +540,6 @@ EXPORT_SYMBOL(tcp_create_openreq_child); * * XXX (TFO) - The current impl contains a special check for ack * validation and inside tcp_v4_reqsk_send_ack(). Can we do better? - * - * We don't need to initialize tmp_opt.sack_ok as we don't use the results */ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, @@ -557,7 +553,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, bool paws_reject = false; bool own_req; - tmp_opt.saw_tstamp = 0; + memset(&tmp_opt, 0, sizeof(tmp_opt)); if (th->doff > (sizeof(struct tcphdr)>>2)) { tcp_parse_options(skb, &tmp_opt, 0, NULL); -- 2.5.5