From: Al Viro <viro@ZenIV.linux.org.uk>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "'tj@kernel.org'" <tj@kernel.org>,
"Hatayama, Daisuke" <d.hatayama@jp.fujitsu.com>,
"'gregkh@linuxfoundation.org'" <gregkh@linuxfoundation.org>,
"Okajima, Toshiyuki" <toshi.okajima@jp.fujitsu.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"'ebiederm@aristanetworks.com'" <ebiederm@aristanetworks.com>
Subject: Re: [CFT][PATCH] kernfs: Correct kernfs directory seeks.
Date: Thu, 7 Jun 2018 19:36:20 +0100 [thread overview]
Message-ID: <20180607183620.GU30522@ZenIV.linux.org.uk> (raw)
In-Reply-To: <8736y1dt1m.fsf@xmission.com>
On Tue, Jun 05, 2018 at 12:47:33PM -0500, Eric W. Biederman wrote:
> Sigh, I have found another issue with kernfs_fop_readdir.
>
> We are not currently protecting file->private_data with the kernfs_mutex
> or any other kind of serialization. Which means if two processes are
> calling readdir on the same file descriptor we might get unpredictable
> behavior.
>
> It doesn't look too bad and easy enough to fix, but definitely something
> to be watchful of.
As discussed off-list - this is not a problem; getdents() et.al. are
serialized on per-struct-file basis by fdget_pos() in relevant syscalls,
since all directories automatically get FMODE_ATOMIC_POS in ->f_mode.
prev parent reply other threads:[~2018-06-07 18:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-28 12:54 [RESEND PATCH v2] kernfs: fix dentry unexpected skip Hatayama, Daisuke
2018-05-28 13:08 ` Hatayama, Daisuke
2018-05-29 16:26 ` 'tj@kernel.org'
2018-06-01 9:25 ` Hatayama, Daisuke
2018-06-01 17:07 ` 'tj@kernel.org'
2018-06-04 9:46 ` Hatayama, Daisuke
2018-06-02 17:25 ` Eric W. Biederman
2018-06-03 18:51 ` [CFT][PATCH] kernfs: Correct kernfs directory seeks Eric W. Biederman
2018-06-04 9:34 ` Hatayama, Daisuke
2018-06-04 14:44 ` Eric W. Biederman
2018-06-05 2:02 ` Eric W. Biederman
2018-06-05 5:52 ` Hatayama, Daisuke
2018-06-05 5:45 ` Hatayama, Daisuke
2018-06-05 15:31 ` Eric W. Biederman
2018-06-05 15:42 ` 'tj@kernel.org'
2018-06-05 17:47 ` Eric W. Biederman
2018-06-07 18:36 ` Al Viro [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180607183620.GU30522@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=d.hatayama@jp.fujitsu.com \
--cc=ebiederm@aristanetworks.com \
--cc=ebiederm@xmission.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tj@kernel.org \
--cc=toshi.okajima@jp.fujitsu.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.