[IFB]: Fix crash on input device removal
The input_device pointer is not refcounted, which means the device may
disappear while packets are queued, causing a crash when ifb passes packets
with a stale skb->dev pointer to netif_rx().
Fix by storing the interface index instead and do a lookup where neccessary.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index ca2b21f..07b4c0d 100644
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -96,17 +96,24 @@
skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
stats->tx_packets++;
stats->tx_bytes +=skb->len;
+
+ skb->dev = __dev_get_by_index(skb->iif);
+ if (!skb->dev) {
+ dev_kfree_skb(skb);
+ stats->tx_dropped++;
+ break;
+ }
+ skb->iif = _dev->ifindex;
+
if (from & AT_EGRESS) {
dp->st_rx_frm_egr++;
dev_queue_xmit(skb);
} else if (from & AT_INGRESS) {
-
dp->st_rx_frm_ing++;
+ skb_pull(skb, skb->dev->hard_header_len);
netif_rx(skb);
- } else {
- dev_kfree_skb(skb);
- stats->tx_dropped++;
- }
+ } else
+ BUG();
}
if (netif_tx_trylock(_dev)) {
@@ -157,26 +164,10 @@
stats->rx_packets++;
stats->rx_bytes+=skb->len;
- if (!from || !skb->input_dev) {
-dropped:
+ if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->iif) {
dev_kfree_skb(skb);
stats->rx_dropped++;
return ret;
- } else {
- /*
- * note we could be going
- * ingress -> egress or
- * egress -> ingress
- */
- skb->dev = skb->input_dev;
- skb->input_dev = dev;
- if (from & AT_INGRESS) {
- skb_pull(skb, skb->dev->hard_header_len);
- } else {
- if (!(from & AT_EGRESS)) {
- goto dropped;
- }
- }
}
if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4ff3940..82f43ad 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -188,7 +188,7 @@
* @sk: Socket we are owned by
* @tstamp: Time we arrived
* @dev: Device we arrived on/are leaving by
- * @input_dev: Device we arrived on
+ * @iif: ifindex of device we arrived on
* @h: Transport layer header
* @nh: Network layer header
* @mac: Link layer header
@@ -235,7 +235,8 @@
struct sock *sk;
struct skb_timeval tstamp;
struct net_device *dev;
- struct net_device *input_dev;
+ int iif;
+ /* 4 byte hole on 64 bit*/
union {
struct tcphdr *th;
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index b902d24..02647fe 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -352,10 +352,13 @@
static inline int
tcf_match_indev(struct sk_buff *skb, char *indev)
{
+ struct net_device *dev;
+
if (indev[0]) {
- if (!skb->input_dev)
+ if (!skb->iif)
return 0;
- if (strcmp(indev, skb->input_dev->name))
+ dev = __dev_get_by_index(skb->iif);
+ if (!dev || strcmp(indev, dev->name))
return 0;
}
diff --git a/net/core/dev.c b/net/core/dev.c
index 5984b55..d44b8f1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1741,8 +1741,8 @@
if (dev->qdisc_ingress) {
__u32 ttl = (__u32) G_TC_RTTL(skb->tc_verd);
if (MAX_RED_LOOP < ttl++) {
- printk(KERN_WARNING "Redir loop detected Dropping packet (%s->%s)\n",
- skb->input_dev->name, skb->dev->name);
+ printk(KERN_WARNING "Redir loop detected Dropping packet (%d->%d)\n",
+ skb->iif, skb->dev->ifindex);
return TC_ACT_SHOT;
}
@@ -1775,8 +1775,8 @@
if (!skb->tstamp.off_sec)
net_timestamp(skb);
- if (!skb->input_dev)
- skb->input_dev = skb->dev;
+ if (!skb->iif)
+ skb->iif = skb->dev->ifindex;
orig_dev = skb_bond(skb);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 702fa8f..87573ae 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -496,7 +496,7 @@
n->tc_verd = SET_TC_VERD(skb->tc_verd,0);
n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
- C(input_dev);
+ C(iif);
#endif
skb_copy_secmark(n, skb);
#endif
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 68f26cb..3e93683 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -198,7 +198,7 @@
skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
skb2->dev = dev;
- skb2->input_dev = skb->dev;
+ skb2->iif = skb->dev->ifindex;
dev_queue_xmit(skb2);
spin_unlock(&m->tcf_lock);
return m->tcf_action;