From: Oleg Nesterov <oleg@redhat.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.cz>, Sergey Dyasly <dserrg@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 4/4] proc: avoid ->f_pos overflows in proc_task_readdir() paths
Date: Tue, 4 Jun 2013 21:57:00 +0200 [thread overview]
Message-ID: <20130604195700.GA31933@redhat.com> (raw)
In-Reply-To: <20130604173917.GB13110@ZenIV.linux.org.uk>
On 06/04, Al Viro wrote:
>
> On Tue, Jun 04, 2013 at 07:14:35PM +0200, Oleg Nesterov wrote:
> > > There is another bug in here as well that we may return really crazy
> > > things in the case of seek simultaneous with readdir.
> >
> > i_mutex? both vfs_readdir() and default_llseek() take it... Anyway, this
> > is another issue.
>
> That's part of the reasons for the series I've mentioned (vfs.git#experimental);
> seriously, check that up.
Will do... but so far I am confused.
I do not see how they could race (I mean /proc/pid/task only). OK, OK,
the usage of ->f_pos in sys_getdents() looks "obviously wrong", but this
is another story? And "put f_pos in a local variable" can't help.
But if you meant other problems with readdir in general, then I seem
to understand, thanks.
Oleg.
next prev parent reply other threads:[~2013-06-04 20:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-03 19:06 [PATCH v2 0/4] proc: first_tid() fix/cleanup Oleg Nesterov
2013-06-03 19:06 ` [PATCH v2 1/4] proc: first_tid: fix the potential use-after-free Oleg Nesterov
2013-06-03 19:07 ` [PATCH v2 2/4] proc: change first_tid() to use while_each_thread() Oleg Nesterov
2013-06-03 19:07 ` [PATCH v2 3/4] proc: simplify proc_task_readdir/first_tid paths Oleg Nesterov
2013-06-03 22:06 ` Eric W. Biederman
2013-06-03 19:07 ` [PATCH v2 4/4] proc: avoid ->f_pos overflows in proc_task_readdir() paths Oleg Nesterov
2013-06-03 22:18 ` Eric W. Biederman
2013-06-04 17:14 ` Oleg Nesterov
2013-06-04 17:39 ` Al Viro
2013-06-04 19:57 ` Oleg Nesterov [this message]
2013-06-04 21:06 ` Al Viro
2013-06-04 0:58 ` Al Viro
2013-06-04 17:35 ` Oleg Nesterov
2013-06-04 17:32 ` [PATCH v2 0/4] proc: first_tid() fix/cleanup Oleg Nesterov
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