From 787d7ac308ff2279e4b2ea393ad4d990de486ef2 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Thu, 7 Jan 2016 14:28:39 +0100 Subject: udp: restrict offloads to one namespace udp tunnel offloads tend to aggregate datagrams based on inner headers. gro engine gets notified by tunnel implementations about possible offloads. The match is solely based on the port number. Imagine a tunnel bound to port 53, the offloading will look into all DNS packets and tries to aggregate them based on the inner data found within. This could lead to data corruption and malformed DNS packets. While this patch minimizes the problem and helps an administrator to find the issue by querying ip tunnel/fou, a better way would be to match on the specific destination ip address so if a user space socket is bound to the same address it will conflict. Cc: Tom Herbert Cc: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv4/fou.c | 2 +- net/ipv4/udp_offload.c | 10 +++++++--- 2 files changed, 8 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index bd903fe0f750..976f0dcf6991 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -498,7 +498,7 @@ static int fou_create(struct net *net, struct fou_cfg *cfg, sk->sk_allocation = GFP_ATOMIC; if (cfg->udp_config.family == AF_INET) { - err = udp_add_offload(&fou->udp_offloads); + err = udp_add_offload(net, &fou->udp_offloads); if (err) goto error; } diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index f9386160cbee..5d396b96ae8b 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -21,6 +21,7 @@ static struct udp_offload_priv __rcu *udp_offload_base __read_mostly; struct udp_offload_priv { struct udp_offload *offload; + possible_net_t net; struct rcu_head rcu; struct udp_offload_priv __rcu *next; }; @@ -241,13 +242,14 @@ out: return segs; } -int udp_add_offload(struct udp_offload *uo) +int udp_add_offload(struct net *net, struct udp_offload *uo) { struct udp_offload_priv *new_offload = kzalloc(sizeof(*new_offload), GFP_ATOMIC); if (!new_offload) return -ENOMEM; + write_pnet(&new_offload->net, net); new_offload->offload = uo; spin_lock(&udp_offload_lock); @@ -311,7 +313,8 @@ struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb, rcu_read_lock(); uo_priv = rcu_dereference(udp_offload_base); for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) { - if (uo_priv->offload->port == uh->dest && + if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) && + uo_priv->offload->port == uh->dest && uo_priv->offload->callbacks.gro_receive) goto unflush; } @@ -389,7 +392,8 @@ int udp_gro_complete(struct sk_buff *skb, int nhoff) uo_priv = rcu_dereference(udp_offload_base); for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) { - if (uo_priv->offload->port == uh->dest && + if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) && + uo_priv->offload->port == uh->dest && uo_priv->offload->callbacks.gro_complete) break; } -- cgit v1.2.3