[PATCH] tun: avoid owner checks on IFF_ATTACH_QUEUE

["Michael S. Tsirkin" <mst@redhat.com>]

At the moment, we check owner when we enable queue in tun.
This seems redundant and will break some valid uses
where fd is passed around: I think TUNSETOWNER is there
to prevent others from attaching to a persistent device not
owned by them. Here the fd is already attached,
enabling/disabling queue is more like read/write.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

---

Note: this is unrelated to Stefan's bugfix.

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index fbd106e..78e3225 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1789,10 +1792,8 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
 		tun = tfile->detached;
 		if (!tun)
 			ret = -EINVAL;
-		else if (tun_not_capable(tun))
-			ret = -EPERM;
 		else
 			ret = tun_attach(tun, file);
 	} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
 		tun = rcu_dereference_protected(tfile->tun,
 						lockdep_rtnl_is_held());
-- 
MST