netdev - Re: [PATCH net v2 1/1] net: tcp: Permit user set TCP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CADVnQy=8DK3B7HriNXums=NLEehkC9aCLK_uMpE7QmJLP6rNWw@mail.gmail.com>
Date:   Mon, 20 Mar 2017 21:23:14 -0400
From:   Neal Cardwell <ncardwell@...gle.com>
To:     fgao@...ai8.com
Cc:     David Miller <davem@...emloft.net>,
        Alexey Kuznetsov <kuznet@....inr.ac.ru>,
        James Morris <jmorris@...ei.org>,
        Eric Dumazet <eric.dumazet@...il.com>,
        Netdev <netdev@...r.kernel.org>, gfree.wind@...il.com
Subject: Re: [PATCH net v2 1/1] net: tcp: Permit user set TCP_MAXSEG to
 default value

On Mon, Mar 20, 2017 at 8:45 PM, <fgao@...ai8.com> wrote:
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 1e319a5..4f7f163 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -2470,7 +2470,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
>                 /* Values greater than interface MTU won't take effect. However
>                  * at the point when this call is done we typically don't yet
>                  * know which interface is going to be used */
> -               if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
> +               if (!val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
>                         err = -EINVAL;
>                         break;

I believe the sense of the val check is flipped in the proposed patch.

I believe Eric suggested:

  if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {

Has this been tested?

neal