>From jesse@nicira.com Tue Dec 7 11:49:39 2010 From: Jesse Gross Date: Mon, 8 Nov 2010 13:23:01 -0800 Subject: [stable] [PATCH 2.6.36 stable] vlan: Avoid hwaccel vlan packets when vid not used. To: stable@kernel.org Cc: netdev@vger.kernel.org, David Miller Message-ID: <1289251381-6671-1-git-send-email-jesse@nicira.com> From: Jesse Gross [This patch applies only to 2.6.36 stable. The problem was introduced in that release and is already fixed by larger changes to the vlan code in 2.6.37.] Normally hardware accelerated vlan packets are quickly dropped if there is no corresponding vlan device configured. The one exception is promiscuous mode, where we allow all of these packets through so they can be picked up by tcpdump. However, this behavior causes a crash if we actually try to receive these packets. This fixes that crash by ignoring packets with vids not corresponding to a configured device in the vlan hwaccel routines and then dropping them before they get to consumers in the network stack. Reported-by: Ben Greear Tested-by: Nikola Ciprich Signed-off-by: Jesse Gross Acked-by: David Miller Signed-off-by: Greg Kroah-Hartman --- net/8021q/vlan_core.c | 3 +++ net/core/dev.c | 13 +++++++++++++ 2 files changed, 16 insertions(+) --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -43,6 +43,9 @@ int vlan_hwaccel_do_receive(struct sk_bu struct net_device *dev = skb->dev; struct vlan_rx_stats *rx_stats; + if (unlikely(!is_vlan_dev(dev))) + return 0; + skb->dev = vlan_dev_info(dev)->real_dev; netif_nit_deliver(skb); --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2891,6 +2891,19 @@ static int __netif_receive_skb(struct sk ncls: #endif + /* If we got this far with a hardware accelerated VLAN tag, it means + * that we were put in promiscuous mode but nobody is interested in + * this vid. Drop the packet now to prevent it from getting propagated + * to other parts of the stack that won't know how to deal with packets + * tagged in this manner. + */ + if (unlikely(vlan_tx_tag_present(skb))) { + if (pt_prev) + ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev); + kfree_skb(skb); + goto out; + } + /* Handle special case of bridge or macvlan */ rx_handler = rcu_dereference(skb->dev->rx_handler); if (rx_handler) {