From: Michael S. Tsirkin <mst@redhat.com>
Date: Thu, 10 Jan 2013 01:31:08 +0000 (+0000)
Subject: tun: avoid owner checks on IFF_ATTACH_QUEUE
X-Git-Tag: v3.8-rc4~29^2~12
X-Git-Url: http://pileus.org/git/?p=~andy%2Flinux;a=commitdiff_plain;h=9d43a18c6e8f868111b983388feeedaea7594fef

tun: avoid owner checks on IFF_ATTACH_QUEUE

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>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index cf6da6efc71..99b58d86217 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1791,8 +1791,6 @@ 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) {