Message ID | 1477495387-36861-1-git-send-email-willemdebruijn.kernel@gmail.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
On Wed, 2016-10-26 at 11:23 -0400, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb@google.com> > > When transmitting on a packet socket with PACKET_VNET_HDR and > PACKET_QDISC_BYPASS, validate device support for features requested > in vnet_hdr. Acked-by: Eric Dumazet <edumazet@google.com>
On 10/26/2016 05:23 PM, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb@google.com> > > When transmitting on a packet socket with PACKET_VNET_HDR and > PACKET_QDISC_BYPASS, validate device support for features requested > in vnet_hdr. > > Drop TSO packets sent to devices that do not support TSO or have the > feature disabled. Note that the latter currently do process those > packets correctly, regardless of not advertising the feature. > > Because of SKB_GSO_DODGY, it is not sufficient to test device features > with netif_needs_gso. Full validate_xmit_skb is needed. > > Switch to software checksum for non-TSO packets that request checksum > offload if that device feature is unsupported or disabled. Note that > similar to the TSO case, device drivers may perform checksum offload > correctly even when not advertising it. > > When switching to software checksum, packets hit skb_checksum_help, > which has two BUG_ON checksum not in linear segment. Packet sockets > always allocate at least up to csum_start + csum_off + 2 as linear. > > Tested by running github.com/wdebruij/kerneltools/psock_txring_vnet.c > > ethtool -K eth0 tso off tx on > psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v > psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v -N > > ethtool -K eth0 tx off > psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G > psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G -N > > v2: > - add EXPORT_SYMBOL_GPL(validate_xmit_skb_list) > > Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option") > Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Date: Wed, 26 Oct 2016 11:23:07 -0400 > From: Willem de Bruijn <willemb@google.com> > > When transmitting on a packet socket with PACKET_VNET_HDR and > PACKET_QDISC_BYPASS, validate device support for features requested > in vnet_hdr. > > Drop TSO packets sent to devices that do not support TSO or have the > feature disabled. Note that the latter currently do process those > packets correctly, regardless of not advertising the feature. > > Because of SKB_GSO_DODGY, it is not sufficient to test device features > with netif_needs_gso. Full validate_xmit_skb is needed. > > Switch to software checksum for non-TSO packets that request checksum > offload if that device feature is unsupported or disabled. Note that > similar to the TSO case, device drivers may perform checksum offload > correctly even when not advertising it. > > When switching to software checksum, packets hit skb_checksum_help, > which has two BUG_ON checksum not in linear segment. Packet sockets > always allocate at least up to csum_start + csum_off + 2 as linear. > > Tested by running github.com/wdebruij/kerneltools/psock_txring_vnet.c > > ethtool -K eth0 tso off tx on > psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v > psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v -N > > ethtool -K eth0 tx off > psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G > psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G -N > > v2: > - add EXPORT_SYMBOL_GPL(validate_xmit_skb_list) > > Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option") > Signed-off-by: Willem de Bruijn <willemb@google.com> Applied and queued up for -stable.
diff --git a/net/core/dev.c b/net/core/dev.c index dbc8713..f745112 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3035,6 +3035,7 @@ struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *d } return head; } +EXPORT_SYMBOL_GPL(validate_xmit_skb_list); static void qdisc_pkt_len_init(struct sk_buff *skb) { diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 11db0d6..d2238b2 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -250,7 +250,7 @@ static void __fanout_link(struct sock *sk, struct packet_sock *po); static int packet_direct_xmit(struct sk_buff *skb) { struct net_device *dev = skb->dev; - netdev_features_t features; + struct sk_buff *orig_skb = skb; struct netdev_queue *txq; int ret = NETDEV_TX_BUSY; @@ -258,9 +258,8 @@ static int packet_direct_xmit(struct sk_buff *skb) !netif_carrier_ok(dev))) goto drop; - features = netif_skb_features(skb); - if (skb_needs_linearize(skb, features) && - __skb_linearize(skb)) + skb = validate_xmit_skb_list(skb, dev); + if (skb != orig_skb) goto drop; txq = skb_get_tx_queue(dev, skb); @@ -280,7 +279,7 @@ static int packet_direct_xmit(struct sk_buff *skb) return ret; drop: atomic_long_inc(&dev->tx_dropped); - kfree_skb(skb); + kfree_skb_list(skb); return NET_XMIT_DROP; }