From 0ad646c81b2182f7fa67ec0c8c825e0ee165696d Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Fri, 13 Oct 2017 11:58:53 -0700 Subject: [PATCH] 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 Cc: Jason Wang Cc: "Michael S. Tsirkin" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- drivers/net/tun.c | 3 +++ include/linux/netdevice.h | 3 +++ net/core/dev.c | 6 +++--- 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) { 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 -- 2.39.5