linux-kernel - Re: [RFC][PATCH] fix move/migrate

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, 24 Feb 2012 10:54:15 -0600 (CST)
From:	Christoph Lameter <cl@...ux.com>
To:	Dave Hansen <dave@...ux.vnet.ibm.com>
cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [RFC][PATCH] fix move/migrate_pages() race on task struct

On Fri, 24 Feb 2012, Dave Hansen wrote:

> On 02/24/2012 07:20 AM, Christoph Lameter wrote:
> > Subject: migration: Do not do rcu_read_unlock until the last time we need the task_struct pointer
> >
> > Migration functions perform the rcu_read_unlock too early. As a result the
> > task pointed to may change. Bugs were introduced when adding security checks
> > because rcu_unlock/lock sequences were inserted. Plus the security checks
> > and do_move_pages used the task_struct pointer after rcu_unlock.
> >
> > Fix those issues by removing the unlock/lock sequences and moving the
> > rcu_read_unlock after the last use of the task struct pointer.
> >
> > Signed-off-by: Christoph Lameter <cl@...ux.com>
>
> It doesn't fix the code duplication, but it definitely does fix the bug

Yes I did not want to override all your good work.

Could you do another patch that removed the duplication?

--
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/