From 0ad646c81b2182f7fa67ec0c8c825e0ee165696d Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Fri, 13 Oct 2017 11:58:53 -0700 Subject: 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 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/net/tun.c') 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; -- cgit v1.2.3 From 5c25f65fd1e42685f7ccd80e0621829c105785d9 Mon Sep 17 00:00:00 2001 From: Julien Gomes Date: Wed, 25 Oct 2017 11:50:50 -0700 Subject: tun: allow positive return values on dev_get_valid_name() call If the name argument of dev_get_valid_name() contains "%d", it will try to assign it a unit number in __dev__alloc_name() and return either the unit number (>= 0) or an error code (< 0). Considering positive values as error values prevent tun device creations relying this mechanism, therefor we should only consider negative values as errors here. Signed-off-by: Julien Gomes Acked-by: Cong Wang Signed-off-by: David S. Miller --- drivers/net/tun.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e21bf90b819f..b9973fb868b7 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2028,7 +2028,7 @@ 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) + if (err < 0) goto err_free_dev; dev_net_set(dev, net); -- cgit v1.2.3 From 63b9ab65bd76e5de6479bb14b4014b64aa1a317a Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Fri, 27 Oct 2017 11:05:44 +0800 Subject: tuntap: properly align skb->head before building skb An unaligned alloc_frag->offset caused by previous allocation will result an unaligned skb->head. This will lead unaligned skb_shared_info and then unaligned dataref which requires to be aligned for accessing on some architecture. Fix this by aligning alloc_frag->offset before the frag refilling. Fixes: 0bbd7dad34f8 ("tun: make tun_build_skb() thread safe") Cc: Eric Dumazet Cc: Willem de Bruijn Cc: Wei Wei Cc: Dmitry Vyukov Cc: Mark Rutland Reported-by: Wei Wei Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index b9973fb868b7..5550f56cb895 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1286,6 +1286,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, buflen += SKB_DATA_ALIGN(len + pad); rcu_read_unlock(); + alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES); if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL))) return ERR_PTR(-ENOMEM); -- cgit v1.2.3