public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public•gmane.org (Eric W. Biederman)
To: David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public•gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org,
	Linux Containers
	<containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public•gmane.org>
Subject: [PATCH net-next ] net: Allow userns root to control tun and tap devices
Date: Sun, 18 Nov 2012 23:34:11 -0800	[thread overview]
Message-ID: <87a9uekpvw.fsf@xmission.com> (raw)


Allow an unpriviled user who has created a user namespace, and then
created a network namespace to effectively use the new network
namespace, by reducing capable(CAP_NET_ADMIN) calls to
ns_capable(net->user_ns,CAP_NET_ADMIN) calls.

Allow setting of the tun iff flags.
Allow creating of tun devices.
Allow adding a new queue to a tun device.

Signed-off-by: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public•gmane.org>
---
 drivers/net/tun.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index b44d7b7..b01e8c0 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -373,10 +373,11 @@ static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
 static inline bool tun_not_capable(struct tun_struct *tun)
 {
 	const struct cred *cred = current_cred();
+	struct net *net = dev_net(tun->dev);
 
 	return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
 		  (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
-		!capable(CAP_NET_ADMIN);
+		!ns_capable(net->user_ns, CAP_NET_ADMIN);
 }
 
 static void tun_set_real_num_queues(struct tun_struct *tun)
@@ -1559,7 +1560,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		char *name;
 		unsigned long flags = 0;
 
-		if (!capable(CAP_NET_ADMIN))
+		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			return -EPERM;
 		err = security_tun_dev_create();
 		if (err < 0)
-- 
1.7.5.4

             reply	other threads:[~2012-11-19  7:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-19  7:34 Eric W. Biederman [this message]
     [not found] ` <87a9uekpvw.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-11-19 14:23   ` [PATCH net-next ] net: Allow userns root to control tun and tap devices Serge E. Hallyn
     [not found]     ` <20121119142331.GA4453-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org>
2012-11-19 19:16       ` David Miller

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=87a9uekpvw.fsf@xmission.com \
    --to=ebiederm-as9lmozglivwk0htik3j/w@public$(echo .)gmane.org \
    --cc=containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public$(echo .)gmane.org \
    --cc=davem-fT/PcQaiUtIeIZ0/mPfg9Q@public$(echo .)gmane.org \
    --cc=netdev-u79uwXL29TY76Z2rM5mHXA@public$(echo .)gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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