From: Jason Wang <jasowang@redhat.com>
To: davem@davemloft.net, mst@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: edumazet@google.com, stefanha@redhat.com,
Jason Wang <jasowang@redhat.com>
Subject: [PATCH V2 2/3] tuntap: forbid calling TUNSETIFF when detached
Date: Sat, 12 Jan 2013 10:59:33 +0800 [thread overview]
Message-ID: <1357959574-13113-3-git-send-email-jasowang@redhat.com> (raw)
In-Reply-To: <1357959574-13113-1-git-send-email-jasowang@redhat.com>
Michael points out that even after Stefan's fix the TUNSETIFF is still allowed
to create a new tap device. This because we only check tfile->tun but the
tfile->detached were introduced. Fix this by failing early in tun_set_iff() if
the file is detached. After this fix, there's no need to do the check again in
tun_set_iff(), so this patch removes it.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
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 aa963c4..a36b56f 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -488,8 +488,6 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
err = -EINVAL;
if (rtnl_dereference(tfile->tun))
goto out;
- if (tfile->detached && tun != tfile->detached)
- goto out;
err = -EBUSY;
if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
@@ -1543,6 +1541,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
struct net_device *dev;
int err;
+ if (tfile->detached)
+ return -EINVAL;
+
dev = __dev_get_by_name(net, ifr->ifr_name);
if (dev) {
if (ifr->ifr_flags & IFF_TUN_EXCL)
--
1.7.1
next prev parent reply other threads:[~2013-01-12 3:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-12 2:59 [PATCH V2 0/3] some fixes of tuntap Jason Wang
2013-01-12 2:59 ` [PATCH V2 1/3] tuntap: switch to use rtnl_dereference() Jason Wang
2013-01-12 2:59 ` Jason Wang [this message]
2013-01-12 2:59 ` [PATCH V2 3/3] tuntap: fix leaking reference count Jason Wang
2013-01-12 3:42 ` [PATCH V2 0/3] some fixes of tuntap David Miller
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