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authorMahesh Bandewar <maheshb@google.com>2016-12-21 17:30:16 -0800
committerDavid S. Miller <davem@davemloft.net>2016-12-23 17:53:47 -0500
commite252536068efd1578c6e23e7323527c5e6e980bd (patch)
tree9ce475c5704e5fd34e5dac3afdb40b9da07e1b81 /drivers/net
parentb1227d019fa98c43381ad8827baf7efbe2923ed1 (diff)
ipvlan: fix multicast processing
In an IPvlan setup when master is set in loopback mode e.g. ethtool -K eth0 set loopback on where eth0 is master device for IPvlan setup. The failure is caused by the faulty logic that determines if the packet is from TX-path vs. RX-path by just looking at the mac- addresses on the packet while processing multicast packets. In the loopback-mode where this crash was happening, the packets that are sent out are reflected by the NIC and are processed on the RX path, but mac-address check tricks into thinking this packet is from TX path and falsely uses dev_forward_skb() to pass packets to the slave (virtual) devices. This patch records the path while queueing packets and eliminates logic of looking at mac-addresses for the same decision. ------------[ cut here ]------------ kernel BUG at include/linux/skbuff.h:1737! Call Trace: [<ffffffff921fbbc2>] dev_forward_skb+0x92/0xd0 [<ffffffffc031ac65>] ipvlan_process_multicast+0x395/0x4c0 [ipvlan] [<ffffffffc031a9a7>] ? ipvlan_process_multicast+0xd7/0x4c0 [ipvlan] [<ffffffff91cdfea7>] ? process_one_work+0x147/0x660 [<ffffffff91cdff09>] process_one_work+0x1a9/0x660 [<ffffffff91cdfea7>] ? process_one_work+0x147/0x660 [<ffffffff91ce086d>] worker_thread+0x11d/0x360 [<ffffffff91ce0750>] ? rescuer_thread+0x350/0x350 [<ffffffff91ce960b>] kthread+0xdb/0xe0 [<ffffffff91c05c70>] ? _raw_spin_unlock_irq+0x30/0x50 [<ffffffff91ce9530>] ? flush_kthread_worker+0xc0/0xc0 [<ffffffff92348b7a>] ret_from_fork+0x9a/0xd0 [<ffffffff91ce9530>] ? flush_kthread_worker+0xc0/0xc0 Fixes: ba35f8588f47 ("ipvlan: Defer multicast / broadcast processing to a work-queue") Signed-off-by: Mahesh Bandewar <maheshb@google.com> CC: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ipvlan/ipvlan.h5
-rw-r--r--drivers/net/ipvlan/ipvlan_core.c26
2 files changed, 20 insertions, 11 deletions
diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h
index 031093e1c25f..dbfbb33ac66c 100644
--- a/drivers/net/ipvlan/ipvlan.h
+++ b/drivers/net/ipvlan/ipvlan.h
@@ -99,6 +99,11 @@ struct ipvl_port {
int count;
};
+struct ipvl_skb_cb {
+ bool tx_pkt;
+};
+#define IPVL_SKB_CB(_skb) ((struct ipvl_skb_cb *)&((_skb)->cb[0]))
+
static inline struct ipvl_port *ipvlan_port_get_rcu(const struct net_device *d)
{
return rcu_dereference(d->rx_handler_data);
diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index ea6bc1e12cdf..83ce74acf82d 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -198,7 +198,7 @@ void ipvlan_process_multicast(struct work_struct *work)
unsigned int mac_hash;
int ret;
u8 pkt_type;
- bool hlocal, dlocal;
+ bool tx_pkt;
__skb_queue_head_init(&list);
@@ -211,7 +211,7 @@ void ipvlan_process_multicast(struct work_struct *work)
bool consumed = false;
ethh = eth_hdr(skb);
- hlocal = ether_addr_equal(ethh->h_source, port->dev->dev_addr);
+ tx_pkt = IPVL_SKB_CB(skb)->tx_pkt;
mac_hash = ipvlan_mac_hash(ethh->h_dest);
if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
@@ -219,13 +219,10 @@ void ipvlan_process_multicast(struct work_struct *work)
else
pkt_type = PACKET_MULTICAST;
- dlocal = false;
rcu_read_lock();
list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
- if (hlocal && (ipvlan->dev == dev)) {
- dlocal = true;
+ if (tx_pkt && (ipvlan->dev == skb->dev))
continue;
- }
if (!test_bit(mac_hash, ipvlan->mac_filters))
continue;
if (!(ipvlan->dev->flags & IFF_UP))
@@ -238,7 +235,7 @@ void ipvlan_process_multicast(struct work_struct *work)
consumed = true;
nskb->pkt_type = pkt_type;
nskb->dev = ipvlan->dev;
- if (hlocal)
+ if (tx_pkt)
ret = dev_forward_skb(ipvlan->dev, nskb);
else
ret = netif_rx(nskb);
@@ -248,7 +245,7 @@ void ipvlan_process_multicast(struct work_struct *work)
}
rcu_read_unlock();
- if (dlocal) {
+ if (tx_pkt) {
/* If the packet originated here, send it out. */
skb->dev = port->dev;
skb->pkt_type = pkt_type;
@@ -480,13 +477,20 @@ out:
}
static void ipvlan_multicast_enqueue(struct ipvl_port *port,
- struct sk_buff *skb)
+ struct sk_buff *skb, bool tx_pkt)
{
if (skb->protocol == htons(ETH_P_PAUSE)) {
kfree_skb(skb);
return;
}
+ /* Record that the deferred packet is from TX or RX path. By
+ * looking at mac-addresses on packet will lead to erronus decisions.
+ * (This would be true for a loopback-mode on master device or a
+ * hair-pin mode of the switch.)
+ */
+ IPVL_SKB_CB(skb)->tx_pkt = tx_pkt;
+
spin_lock(&port->backlog.lock);
if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
if (skb->dev)
@@ -549,7 +553,7 @@ static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
} else if (is_multicast_ether_addr(eth->h_dest)) {
ipvlan_skb_crossing_ns(skb, NULL);
- ipvlan_multicast_enqueue(ipvlan->port, skb);
+ ipvlan_multicast_enqueue(ipvlan->port, skb, true);
return NET_XMIT_SUCCESS;
}
@@ -646,7 +650,7 @@ static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
*/
if (nskb) {
ipvlan_skb_crossing_ns(nskb, NULL);
- ipvlan_multicast_enqueue(port, nskb);
+ ipvlan_multicast_enqueue(port, nskb, false);
}
}
} else {