netdev - Re: [PATCH net-next-2.6 v2] pkt_sched: gen_estimator: kill est

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: <20100608121546.GA9392@ff.dom.local>
Date:	Tue, 8 Jun 2010 12:15:46 +0000
From:	Jarek Poplawski <jarkao2@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Changli Gao <xiaosuo@...il.com>,
	David Miller <davem@...emloft.net>,
	netdev <netdev@...r.kernel.org>,
	Stephen Hemminger <shemminger@...tta.com>,
	Patrick McHardy <kaber@...sh.net>
Subject: Re: [PATCH net-next-2.6 v2] pkt_sched: gen_estimator: kill
	est_lock rwlock

Eric Dumazet wrote:
...
> [PATCH net-next-2.6] pkt_sched: gen_kill_estimator() rcu fixes
> 
> gen_kill_estimator() API is fundamentaly wrong, since caller should make
> sure an RCU grace period is respected before freeing bstats or lock.
> 
> This was partially addressed in commit 5d944c640b4 (gen_estimator:
> deadlock fix), but same problem exist for all gen_kill_estimator()
> users.
> 
> Change its name to gen_kill_estimator_rcu() and change all callers to
> use RCU grace period before freeing bstats container.
> 
> As a bonus, est_lock rwlock can be killed for good.
> 
> Special thanks to Changli Gao for commenting on a previous patch, this
> made this bug clear to me.
> 

Actually, I guess, Changli meant the bug introduced by your previous
patch by removing the est_lock. With this lock (and your commit 5d944)
bstats (and API) seem "fundamentaly" safe.

Jarek P.
--
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