[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) {