| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Wed, 21 Dec 2016 17:30:16 -0800
From: Mahesh Bandewar <mahesh@...dewar.net>
To: netdev <netdev@...r.kernel.org>,
Eric Dumazet <edumazet@...gle.com>,
David Miller <davem@...emloft.net>
Cc: Mahesh Bandewar <maheshb@...gle.com>
Subject: [PATCH net] ipvlan: fix multicast processing
From: Mahesh Bandewar <maheshb@...gle.com>
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@...gle.com>
CC: Eric Dumazet <edumazet@...gle.com>
---
Note that this is on top of Eric's patch sent earlier.
drivers/net/ipvlan/ipvlan.h | 5 +++++
drivers/net/ipvlan/ipvlan_core.c | 26 +++++++++++++++-----------
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 @@ static int ipvlan_process_outbound(struct sk_buff *skb)
}
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 {
--
2.8.0.rc3.226.g39d4020
Powered by blists - more mailing lists