From: Matthew Bobrowski <repnop@google.com>
To: Jan Kara <jack@suse.cz>
Cc: amir73il@gmail.com, christian.brauner@ubuntu.com,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org
Subject: Re: [PATCH v2 5/5] fanotify: add pidfd support to the fanotify API
Date: Fri, 11 Jun 2021 10:32:24 +1000 [thread overview]
Message-ID: <YMKvGEvNISpIOOFE@google.com> (raw)
In-Reply-To: <20210610112331.GB23539@quack2.suse.cz>
On Thu, Jun 10, 2021 at 01:23:31PM +0200, Jan Kara wrote:
> > @@ -524,6 +561,34 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
> > }
> > metadata.fd = fd;
> >
> > + /*
> > + * Currently, reporting a pidfd to an unprivileged listener is not
> > + * supported. The FANOTIFY_UNPRIV flag is to be kept here so that a
> > + * pidfd is not accidentally leaked to an unprivileged listener.
> > + */
> > + if (pidfd_mode && !FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV)) {
>
> Hum, you've added FAN_REPORT_PIDFD to FANOTIFY_ADMIN_INIT_FLAGS so this
> condition should be always true? I don't think we need to be that much
> defensive and would just drop the check here.
Yes, that's right, so dropping this check is also fine with me.
> > @@ -558,6 +632,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
> > put_unused_fd(fd);
> > fput(f);
> > }
> > +
> > + if (pidfd < 0)
> > + put_unused_fd(pidfd);
> > +
>
> put_unused_fd() is not enough to destroy the pidfd you have. That will just
> mark 'pidfd' as free in the fd table. You rather need to call close_fd()
> here to fully close open file.
Ah, I see, put_unused_fd() doesn't free up the file instance. I will swap
this out with close_fd() instead.
Thanks for the suggestions Jan!
/M
next prev parent reply other threads:[~2021-06-11 0:32 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 0:19 [PATCH v2 0/5] Add pidfd support to the fanotify API Matthew Bobrowski
2021-06-10 0:20 ` [PATCH v2 1/5] kernel/pid.c: remove static qualifier from pidfd_create() Matthew Bobrowski
2021-06-15 11:34 ` Christian Brauner
2021-06-10 0:20 ` [PATCH v2 2/5] kernel/pid.c: implement additional checks upon pidfd_create() parameters Matthew Bobrowski
2021-06-15 11:35 ` Christian Brauner
2021-06-10 0:21 ` [PATCH v2 3/5] fanotify/fanotify_user.c: minor cosmetic adjustments to fid labels Matthew Bobrowski
2021-06-10 0:21 ` [PATCH v2 4/5] fanotify/fanotify_user.c: introduce a generic info record copying helper Matthew Bobrowski
2021-06-10 0:21 ` [PATCH v2 5/5] fanotify: add pidfd support to the fanotify API Matthew Bobrowski
2021-06-10 5:18 ` Amir Goldstein
2021-06-10 6:35 ` Matthew Bobrowski
2021-06-10 7:11 ` Amir Goldstein
2021-06-10 7:24 ` Matthew Bobrowski
2021-06-10 11:23 ` Jan Kara
2021-06-11 0:32 ` Matthew Bobrowski [this message]
2021-07-10 14:49 ` Amir Goldstein
2021-07-14 0:18 ` Matthew Bobrowski
2021-06-10 5:37 ` [PATCH v2 0/5] Add " Amir Goldstein
2021-06-10 6:55 ` Matthew Bobrowski
2021-06-10 11:32 ` Jan Kara
2021-06-11 0:35 ` Matthew Bobrowski
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=YMKvGEvNISpIOOFE@google.com \
--to=repnop@google.com \
--cc=amir73il@gmail.com \
--cc=christian.brauner@ubuntu.com \
--cc=jack@suse.cz \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).