Re: [PATCH net-next ] net: Allow userns root to control tun and tap devices
From: Serge E. Hallyn <hidden>
Date: 2012-11-19 14:23:31
Quoting Eric W. Biederman (ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org):
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.
Acked-by: Serge Hallyn <redacted>
quoted hunk
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