linux-kernel - Re: rwsem exit_to

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>] [day] [month] [year] [list]

Message-ID: <20160211200356.GA10716@redhat.com>
Date:	Thu, 11 Feb 2016 21:03:57 +0100
From:	Oleg Nesterov <oleg@...hat.com>
To:	Andy Lutomirski <luto@...capital.net>
Cc:	Justin Capella <justincapella@...il.com>,
	Andrew Lutomirski <luto@...nel.org>,
	linux-kernel@...r.kernel.org
Subject: Re: rwsem exit_to_usermode

On 02/10, Andy Lutomirski wrote:
>
> On Wed, Feb 10, 2016 at 5:05 PM, Justin Capella <justincapella@...il.com> wrote:
> > http://i.imgur.com/gKamNV3.jpg
> >
> > I encountered this deadlock situation, let me know if there is additional
> > info I can provide, if you're interested...
>
> You're the second person in 24 hours to privately report a bug in that code :-/

Let me add lkml,

> This looks like it's a signal thing, not an entry/exit thing, though.

Looks like someone holds cgroup_threadgroup_rwsem for writing.

Which kernel version? It would be nice to look at sysrq-T output...

Oleg.