linux-kernel - Re: [3.16.1 BISECTED REGRESSION]: Simtec Entropy Key (cdc-acm) broken in 3.16

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 for Android: free password hash cracker in your pocket

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

Message-ID: <87bnok8d5o.fsf@spindle.srvr.nix>
Date:	Thu, 06 Nov 2014 17:14:11 +0000
From:	Nix <nix@...eri.org.uk>
To:	Johan Hovold <johan@...nel.org>
Cc:	Paul Martin <pm@...ian.org>,
	Daniel Silverstone <dsilvers@...ian.org>,
	Oliver Neukum <oliver@...kum.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org
Subject: Re: [3.16.1 BISECTED REGRESSION]: Simtec Entropy Key (cdc-acm) broken in 3.16

On 6 Nov 2014, Johan Hovold said:

> On Thu, Nov 06, 2014 at 01:49:13PM +0000, Nix wrote:
>> On 5 Nov 2014, Johan Hovold told this:
>> > On Wed, Nov 05, 2014 at 03:14:49PM +0000, Nix wrote:
>
>> > Could you try two more things (too make sure line control is really the
>> > culprit):
>> >
>> > 1. If you clear HUPCL in ekeyd so that the lines are never lowered, does
>> > that fix the stability issue?
>> 
>> Definitely not. I got a hang after the first reboot out of an afflicted
>> kernel, when using a HUPCLless ekeyd. Weird. (I guess they're lowered on
>> reboot anyway?)
>
> It's actually only the timings related to the control-lines being raised
> on open that has changed, so this would seem consistent with that.

Urgh. No wonder it was intermittent.

> Thanks for tracking this down. That bisect cannot have been fun given
> the low failure rate (sometimes only one in ten reboots?).

It often failed quite fast, but yes, the negative case was hard to
prove: I had to rewind twice. I counted reboots because I'm a flaming
aspie pedant. 173 reboots that took... thank goodness it replicated on
the machine of mine that's fastest to reboot!

-- 
NULL && (void)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/