netdev - RE: [PATCH net] sctp: fix race on protocol/netns initialization

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: <063D6719AE5E284EB5DD2968C1650D6D1CB91B0A@AcuExch.aculab.com>
Date:	Thu, 10 Sep 2015 15:03:36 +0000
From:	David Laight <David.Laight@...LAB.COM>
To:	'Marcelo Ricardo Leitner' <marcelo.leitner@...il.com>,
	David Miller <davem@...emloft.net>
CC:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"vyasevich@...il.com" <vyasevich@...il.com>,
	"nhorman@...driver.com" <nhorman@...driver.com>,
	"linux-sctp@...r.kernel.org" <linux-sctp@...r.kernel.org>
Subject: RE: [PATCH net] sctp: fix race on protocol/netns initialization

From: Marcelo Ricardo 
> Sent: 10 September 2015 15:36
...
> > Given that the first ->create() blocks while the protocol code loads
> > it really wouldn't be right to error a subsequent ->create() because
> > the load hasn't completed.
> 
> Can't say I don't agree with you, but at the same time, there are other
> temporary errors that can happen and that the user should just retry.
> This would be just another condition in a trade off for avoiding complexity.

We do retry, but the delay messes up out test scripts :-(

> > I hold a semaphore across sock_create_kern() because of issues with sctp.
> > (Current kernels are nowhere near as bad as really old ones though.)
> 
> Oh, that's not good to hear. I'll experiment with that later, try to
> catch some bugs. :)

I mean REALLY old - like 2.6.12 (FC3).
I'm pretty sure I've seen oops as well as create failing.

We don't create enough sockets for the semaphore to be a problem.

OTOH I've a current problem with a customer using RHEL5.8 (basically 2.6.18).
They might manage to move to RHEL6 (2.6.32) - but that could take a year or two.
RH might be pulling some of the SCTP fixes, but I doubt they get priority.

	David

--
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