linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>, Harsh Jain <harsh@chelsio.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	Atul Gupta <atul.gupta@chelsio.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: y2038@lists.linaro.org, "Michael Werner" <werner@chelsio.com>,
	"Neal Cardwell" <ncardwell@google.com>,
	"Yuchung Cheng" <ycheng@google.com>,
	"Soheil Hassas Yeganeh" <soheil@google.com>,
	"Florian Westphal" <fw@strlen.de>,
	"Christoph Paasch" <cpaasch@apple.com>,
	"Lawrence Brakmo" <brakmo@fb.com>,
	"Ursula Braun" <ubraun@linux.vnet.ibm.com>,
	"Priyaranjan Jha" <priyarjha@google.com>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"David Ahern" <dsahern@gmail.com>,
	"Ivan Delalande" <colona@arista.com>,
	"Maciej Żenczykowski" <maze@google.com>,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org
Subject: Re: [PATCH net-next 3/3] tcp: use monotonic timestamps for PAWS
Date: Mon, 18 Jun 2018 08:59:34 -0700	[thread overview]
Message-ID: <67ebb94d-c73f-6c9f-493b-00c86f595120@gmail.com> (raw)
In-Reply-To: <20180618152242.1566661-3-arnd@arndb.de>



On 06/18/2018 08:22 AM, Arnd Bergmann wrote:
> Using get_seconds() for timestamps is deprecated since it can lead
> to overflows on 32-bit systems. While the interface generally doesn't
> overflow until year 2106, the specific implementation of the TCP PAWS
> algorithm breaks in 2038 when the intermediate signed 32-bit timestamps
> overflow.
>
...

>
>  
>  static inline u32 tcp_cookie_time(void)
> @@ -1361,7 +1362,7 @@ static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt,
>  {
>  	if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win)
>  		return true;
> -	if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS))
> +	if (unlikely(ktime_get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS))
>  		return true;
>  	/*
>  	 * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0,
> @@ -1391,7 +1392,7 @@ static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt,
>  
>  	   However, we can relax time bounds for RST segments to MSL.
>  	 */
> -	if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
> +	if (rst && ktime_get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
>  		return false;
>  	return true;



Please use the time_after32(), since ktime_get_seconds() is time64_t while ts_recent_stamp is int.

Same remark for tcp_twsk_unique()

Lets clean up this stuff, thanks !


  reply	other threads:[~2018-06-18 15:59 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-18 15:22 [PATCH net-next 1/3] xfrm: use time64_t for in-kernel timestamps Arnd Bergmann
2018-06-18 15:22 ` [PATCH net-next 2/3] ipv6: xfrm: use 64-bit timestamps Arnd Bergmann
2018-06-18 15:22 ` [PATCH net-next 3/3] tcp: use monotonic timestamps for PAWS Arnd Bergmann
2018-06-18 15:59   ` Eric Dumazet [this message]
2018-06-19  9:23     ` Arnd Bergmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=67ebb94d-c73f-6c9f-493b-00c86f595120@gmail.com \
    --to=eric.dumazet@gmail.com \
    --cc=arnd@arndb.de \
    --cc=ast@kernel.org \
    --cc=atul.gupta@chelsio.com \
    --cc=brakmo@fb.com \
    --cc=colona@arista.com \
    --cc=cpaasch@apple.com \
    --cc=davem@davemloft.net \
    --cc=dsahern@gmail.com \
    --cc=edumazet@google.com \
    --cc=fw@strlen.de \
    --cc=gustavo@embeddedor.com \
    --cc=harsh@chelsio.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=kuznet@ms2.inr.ac.ru \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maze@google.com \
    --cc=ncardwell@google.com \
    --cc=netdev@vger.kernel.org \
    --cc=priyarjha@google.com \
    --cc=soheil@google.com \
    --cc=ubraun@linux.vnet.ibm.com \
    --cc=werner@chelsio.com \
    --cc=y2038@lists.linaro.org \
    --cc=ycheng@google.com \
    --cc=yoshfuji@linux-ipv6.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).