netdev - Re: [PATCH] net:ipv4: send an ack when seg.ack

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]

Date:   Sat, 19 Mar 2022 11:04:43 +0100
From:   Florian Westphal <fw@...len.de>
To:     zhouzhouyi@...il.com
Cc:     edumazet@...gle.com, davem@...emloft.net, yoshfuji@...ux-ipv6.org,
        dsahern@...nel.org, kuba@...nel.org, pabeni@...hat.com,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Wei Xu <xuweihf@...c.edu.cn>
Subject: Re: [PATCH] net:ipv4: send an ack when seg.ack > snd.nxt

zhouzhouyi@...il.com <zhouzhouyi@...il.com> wrote:
> -	if (after(ack, tp->snd_nxt))
> +	if (after(ack, tp->snd_nxt)) {
> +		tcp_send_ack(sk);
>  		return -1;
> +	}

If we really need to do this we need to
  if (!(flag & FLAG_NO_CHALLENGE_ACK))
	tcp_send_challenge_ack(sk);

... else this might result in two acks?
Whats the problem thats being fixed here?