| Message ID | 1494237477-19023-1-git-send-email-liuhangbin@gmail.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mon, 2017-05-08 at 17:57 +0800, Hangbin Liu wrote: > 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. Patch is not needed at all. Comment and code are pretty clear. This part of the code uses a generic function ( tcp_parse_options()) to decode TCP options, but we are only caring about TS one.
On Mon, May 08, 2017 at 07:49:23AM -0700, Eric Dumazet wrote: > On Mon, 2017-05-08 at 17:57 +0800, Hangbin Liu wrote: > > 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. > > Patch is not needed at all. > > Comment and code are pretty clear. > > This part of the code uses a generic function ( tcp_parse_options()) to > decode TCP options, but we are only caring about TS one. OK, got it. Thanks for the explanation and sorry for the inconvenience. Best Regards Hangbin
On Tue, 2017-05-09 at 21:22 +0800, Hangbin Liu wrote: > On Mon, May 08, 2017 at 07:49:23AM -0700, Eric Dumazet wrote: > > On Mon, 2017-05-08 at 17:57 +0800, Hangbin Liu wrote: > > > 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. > > > > Patch is not needed at all. > > > > Comment and code are pretty clear. > > > > This part of the code uses a generic function ( tcp_parse_options()) to > > decode TCP options, but we are only caring about TS one. > > OK, got it. Thanks for the explanation and sorry for the inconvenience. No inconvenience taken ;)
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);
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 <liuhangbin@gmail.com> --- net/ipv4/tcp_minisocks.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)