diff options
authorCong Wang <xiyou.wangcong@gmail.com>2017-10-13 11:58:53 -0700
committerDavid S. Miller <davem@davemloft.net>2017-10-16 21:02:54 +0100
commit0ad646c81b2182f7fa67ec0c8c825e0ee165696d (patch)
parentnet: enable interface alias removal via rtnl (diff)
tun: call dev_get_valid_name() before register_netdevice()
register_netdevice() could fail early when we have an invalid dev name, in which case ->ndo_uninit() is not called. For tun device, this is a problem because a timer etc. are already initialized and it expects ->ndo_uninit() to clean them up. We could move these initializations into a ->ndo_init() so that register_netdevice() knows better, however this is still complicated due to the logic in tun_detach(). Therefore, I choose to just call dev_get_valid_name() before register_netdevice(), which is quicker and much easier to audit. And for this specific case, it is already enough. Fixes: 96442e42429e ("tuntap: choose the txq based on rxq") Reported-by: Dmitry Alexeev <avekceeb@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
3 files changed, 9 insertions, 3 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 5ce580f413b9..e21bf90b819f 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2027,6 +2027,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (!dev)
return -ENOMEM;
+ err = dev_get_valid_name(net, dev, name);
+ if (err)
+ goto err_free_dev;
dev_net_set(dev, net);
dev->rtnl_link_ops = &tun_link_ops;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f535779d9dc1..2eaac7d75af4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3694,6 +3694,9 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
unsigned char name_assign_type,
void (*setup)(struct net_device *),
unsigned int txqs, unsigned int rxqs);
+int dev_get_valid_name(struct net *net, struct net_device *dev,
+ const char *name);
#define alloc_netdev(sizeof_priv, name, name_assign_type, setup) \
alloc_netdev_mqs(sizeof_priv, name, name_assign_type, setup, 1, 1)
diff --git a/net/core/dev.c b/net/core/dev.c
index 588b473194a8..11596a302a26 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1147,9 +1147,8 @@ static int dev_alloc_name_ns(struct net *net,
return ret;
-static int dev_get_valid_name(struct net *net,
- struct net_device *dev,
- const char *name)
+int dev_get_valid_name(struct net *net, struct net_device *dev,
+ const char *name)
@@ -1165,6 +1164,7 @@ static int dev_get_valid_name(struct net *net,
return 0;
* dev_change_name - change name of a device