4.4-stable review patch. If anyone has any objections, please let me know.
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From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit 0ad646c81b2182f7fa67ec0c8c825e0ee165696d ]
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/tun.c | 3 +++ include/linux/netdevice.h | 3 +++ net/core/dev.c | 6 +++--- 3 files changed, 9 insertions(+), 3 deletions(-)
--- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1684,6 +1684,9 @@ static int tun_set_iff(struct net *net,
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; --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3469,6 +3469,9 @@ struct net_device *alloc_netdev_mqs(int 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)
--- a/net/core/dev.c +++ b/net/core/dev.c @@ -1111,9 +1111,8 @@ static int dev_alloc_name_ns(struct 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) { BUG_ON(!net);
@@ -1129,6 +1128,7 @@ static int dev_get_valid_name(struct net
return 0; } +EXPORT_SYMBOL(dev_get_valid_name);
/** * dev_change_name - change name of a device