tun: call dev_get_valid_name() before register_netdevice() (0ad646c8) · Commits · 戴 / test

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: ("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>

drivers/net/tun.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;

include/linux/netdevice.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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)

net/core/dev.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1147,8 +1147,7 @@ static int dev_alloc_name_ns(struct net *net,
		return ret;
		}

		static int dev_get_valid_name(struct net *net,
		struct net_device *dev,
		int dev_get_valid_name(struct net net, struct net_device dev,
		const char *name)
		{
		BUG_ON(!net);
		@@ -1165,6 +1164,7 @@ static int dev_get_valid_name(struct net *net,

		return 0;
		}
		EXPORT_SYMBOL(dev_get_valid_name);

		/**
		* dev_change_name - change name of a device

Admin message