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From: "Serge E. Hallyn" <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>
To: Andrei Vagin <avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
Cc: Serge Hallyn
	<serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
	linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Alexander Viro
	<viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>,
	James Bottomley
	<James.Bottomley-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org>,
	"Eric W. Biederman"
	<ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	"Michael Kerrisk (man-pages)"
	<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH 1/4] kernel: add a helper to get an owning user namespace for a namespace
Date: Tue, 30 Aug 2016 21:56:05 -0500	[thread overview]
Message-ID: <20160831025605.GA21788@mail.hallyn.com> (raw)
In-Reply-To: <1472252891-4963-2-git-send-email-avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>

On Fri, Aug 26, 2016 at 04:08:08PM -0700, Andrei Vagin wrote:
> +struct ns_common *ns_get_owner(struct ns_common *ns)
> +{
> +	struct user_namespace *my_user_ns = current_user_ns();
> +	struct user_namespace *owner, *p;
> +
> +	/* See if the owner is in the current user namespace */
> +	owner = p = ns->ops->get_owner(ns);
> +	for (;;) {
> +		if (!p)
> +			return ERR_PTR(-EPERM);
> +		if (p == my_user_ns)
> +			break;
> +		p = p->parent;
> +	}
> +
> +	return &get_user_ns(owner)->ns;

get_user_ns() bumps the owner's refcount.  I don't see where
this is being dropped, especially when ns_ioctl() uses it in
the next patch.

  parent reply	other threads:[~2016-08-31  2:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-26 23:08 [PATCH 0/4 v2] Add an interface to discover relationships between namespaces Andrei Vagin
     [not found] ` <1472252891-4963-1-git-send-email-avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2016-08-26 23:08   ` [PATCH 1/4] kernel: add a helper to get an owning user namespace for a namespace Andrei Vagin
     [not found]     ` <1472252891-4963-2-git-send-email-avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2016-08-31  2:41       ` Serge E. Hallyn
     [not found]         ` <20160831024146.GB21475-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org>
2016-08-31 21:12           ` Andrey Vagin
2016-08-31 21:59             ` Serge E. Hallyn
2016-08-31  2:56       ` Serge E. Hallyn [this message]
     [not found]         ` <20160831025605.GA21788-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org>
2016-08-31 20:38           ` Andrey Vagin
     [not found]             ` <CANaxB-zz=tnCSFMsHuGbmhiHa20DGbybWo=xdeeiDwJyoMxmYQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-09-01  5:12               ` Serge E. Hallyn
2016-08-26 23:08   ` [PATCH 2/4] nsfs: add ioctl to get an owning user namespace for ns file descriptor Andrei Vagin
2016-08-26 23:08   ` [PATCH 3/4] nsfs: add ioctl to get a parent namespace Andrei Vagin
2016-08-26 23:08   ` [PATCH 4/4] tools/testing: add a test to check nsfs ioctl-s Andrei Vagin
  -- strict thread matches above, loose matches on Subject: below --
2016-09-06  7:47 [PATCH 0/4 v3] Add an interface to discover relationships between namespaces Andrei Vagin
     [not found] ` <1473148036-32630-1-git-send-email-avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2016-09-06  7:47   ` [PATCH 1/4] kernel: add a helper to get an owning user namespace for a namespace Andrei Vagin

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