Commit c01003c2 authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller

[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: default avatarPatrick McHardy <kaber@trash.net>
Acked-by: default avatarJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent db8b2255
......@@ -96,17 +96,24 @@ static void ri_tasklet(unsigned long dev)
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 @@ static int ifb_xmit(struct sk_buff *skb, struct net_device *dev)
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) {
......
......@@ -188,7 +188,7 @@ enum {
* @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 sk_buff {
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;
......
......@@ -352,10 +352,13 @@ tcf_change_indev(struct tcf_proto *tp, char *indev, struct rtattr *indev_tlv)
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;
}
......
......@@ -1741,8 +1741,8 @@ static int ing_filter(struct sk_buff *skb)
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 @@ int netif_receive_skb(struct sk_buff *skb)
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);
......
......@@ -496,7 +496,7 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
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
......
......@@ -198,7 +198,7 @@ bad_mirred:
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;
......
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