Subject: [PATCH] appletalk: Fix skb leak when ipddp interface is not loaded

And also do a better job of returning proper NET_{RX,XMIT}_ values.

Based on a patch and suggestions by Mark Smith.

This fixes CVE-2009-2903

Reported-by: Mark Smith <lk-netdev@lk-netdev.nosense.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo 2009-09-11 11:35:22 -07:00 коммит произвёл David S. Miller
Родитель 8ba69ba6a3
Коммит ffcfb8db54
3 изменённых файлов: 36 добавлений и 30 удалений

Просмотреть файл

@ -177,8 +177,7 @@ static netdev_tx_t ipddp_xmit(struct sk_buff *skb, struct net_device *dev)
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
if(aarp_send_ddp(rt->dev, skb, &rt->at, NULL) < 0)
dev_kfree_skb(skb);
aarp_send_ddp(rt->dev, skb, &rt->at, NULL);
spin_unlock(&ipddp_route_lock);

Просмотреть файл

@ -599,7 +599,7 @@ int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb,
/* Non ELAP we cannot do. */
if (dev->type != ARPHRD_ETHER)
return -1;
goto free_it;
skb->dev = dev;
skb->protocol = htons(ETH_P_ATALK);
@ -634,7 +634,7 @@ int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb,
if (!a) {
/* Whoops slipped... good job it's an unreliable protocol 8) */
write_unlock_bh(&aarp_lock);
return -1;
goto free_it;
}
/* Set up the queue */
@ -663,15 +663,21 @@ out_unlock:
write_unlock_bh(&aarp_lock);
/* Tell the ddp layer we have taken over for this frame. */
return 0;
goto sent;
sendit:
if (skb->sk)
skb->priority = skb->sk->sk_priority;
dev_queue_xmit(skb);
if (dev_queue_xmit(skb))
goto drop;
sent:
return 1;
return NET_XMIT_SUCCESS;
free_it:
kfree_skb(skb);
drop:
return NET_XMIT_DROP;
}
EXPORT_SYMBOL(aarp_send_ddp);
/*
* An entry in the aarp unresolved queue has become resolved. Send

Просмотреть файл

@ -1270,8 +1270,10 @@ static int handle_ip_over_ddp(struct sk_buff *skb)
struct net_device_stats *stats;
/* This needs to be able to handle ipddp"N" devices */
if (!dev)
return -ENODEV;
if (!dev) {
kfree_skb(skb);
return NET_RX_DROP;
}
skb->protocol = htons(ETH_P_IP);
skb_pull(skb, 13);
@ -1281,8 +1283,7 @@ static int handle_ip_over_ddp(struct sk_buff *skb)
stats = netdev_priv(dev);
stats->rx_packets++;
stats->rx_bytes += skb->len + 13;
netif_rx(skb); /* Send the SKB up to a higher place. */
return 0;
return netif_rx(skb); /* Send the SKB up to a higher place. */
}
#else
/* make it easy for gcc to optimize this test out, i.e. kill the code */
@ -1290,9 +1291,8 @@ static int handle_ip_over_ddp(struct sk_buff *skb)
#define handle_ip_over_ddp(skb) 0
#endif
static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
struct ddpehdr *ddp, __u16 len_hops,
int origlen)
static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
struct ddpehdr *ddp, __u16 len_hops, int origlen)
{
struct atalk_route *rt;
struct atalk_addr ta;
@ -1359,8 +1359,6 @@ static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
/* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
kfree_skb(skb);
if (!nskb)
goto out;
skb = nskb;
} else
skb = skb_unshare(skb, GFP_ATOMIC);
@ -1369,12 +1367,16 @@ static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
* If the buffer didn't vanish into the lack of space bitbucket we can
* send it.
*/
if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
goto free_it;
out:
return;
if (skb == NULL)
goto drop;
if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
return NET_RX_DROP;
return NET_XMIT_SUCCESS;
free_it:
kfree_skb(skb);
drop:
return NET_RX_DROP;
}
/**
@ -1448,8 +1450,7 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
/* Not ours, so we route the packet via the correct
* AppleTalk iface
*/
atalk_route_packet(skb, dev, ddp, len_hops, origlen);
return NET_RX_SUCCESS;
return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
}
/* if IP over DDP is not selected this code will be optimized out */
@ -1655,10 +1656,10 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
if (skb2) {
loopback = 1;
SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
if (aarp_send_ddp(dev, skb2,
&usat->sat_addr, NULL) == -1)
kfree_skb(skb2);
/* else queued/sent above in the aarp queue */
/*
* If it fails it is queued/sent above in the aarp queue
*/
aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
}
}
@ -1688,9 +1689,10 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
usat = &gsat;
}
if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
kfree_skb(skb);
/* else queued/sent above in the aarp queue */
/*
* If it fails it is queued/sent above in the aarp queue
*/
aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
}
SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
@ -1868,7 +1870,6 @@ static struct packet_type ppptalk_packet_type __read_mostly = {
static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
/* Export symbols for use by drivers when AppleTalk is a module */
EXPORT_SYMBOL(aarp_send_ddp);
EXPORT_SYMBOL(atrtr_get_dev);
EXPORT_SYMBOL(atalk_find_dev_addr);