netdev - Re: [net-next-2.6 PATCH v6 2/7 RFC] TCPCT part 1b: generate Responder Cookie

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:	Fri, 13 Nov 2009 09:35:36 -0500
From:	William Allen Simpson <william.allen.simpson@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
CC:	Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: [net-next-2.6 PATCH v6 2/7 RFC] TCPCT part 1b: generate Responder
 Cookie

Eric Dumazet wrote:
> Small point :
> 
> +	if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) {
> +		spin_lock_bh(&tcp_secret_locker);
> +		if (!time_after_eq(jiffy, tcp_secret_generating->expires)) {
> +			/* refreshed by another */
> +			spin_unlock_bh(&tcp_secret_locker);
> +			memcpy(bakery,
> +			       &tcp_secret_generating->secrets[0],
> +			       sizeof(tcp_secret_generating->secrets));
> 
> Technically speaking, you should perform the memcpy() before spin_unlock_bh()
> 
> +	if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) {
> +		spin_lock_bh(&tcp_secret_locker);
> +		if (!time_after_eq(jiffy, tcp_secret_generating->expires)) {
> +			/* refreshed by another */
> +			memcpy(bakery,
> +			       &tcp_secret_generating->secrets[0],
> +			       sizeof(tcp_secret_generating->secrets));
> +			spin_unlock_bh(&tcp_secret_locker);
> 
Technically speaking is exactly what I need!  I'd thought from your
earlier description of memory barriers that it should be after the unlock.
Done.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html