Subject: [PATCH] af_iucv: drop skbs rejected by filter

A packet filter might be installed for instance with setsockopt
SO_ATTACH_FILTER. af_iucv currently queues skbs rejected by filter
into the backlog queue. This does not make sense, since packets
rejected by filter can be dropped immediately. This patch adds
separate sk_filter return code checking, and dropping of packets
if applicable.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ursula Braun 2016-10-07 15:51:48 +02:00 committed by David S. Miller
parent 4e0ad32216
commit 8c68b1a0e9
1 changed files with 17 additions and 7 deletions

View File

@ -1323,8 +1323,13 @@ static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
}
IUCV_SKB_CB(skb)->offset = 0;
if (sock_queue_rcv_skb(sk, skb))
skb_queue_head(&iucv_sk(sk)->backlog_skb_q, skb);
if (sk_filter(sk, skb)) {
atomic_inc(&sk->sk_drops); /* skb rejected by filter */
kfree_skb(skb);
return;
}
if (__sock_queue_rcv_skb(sk, skb)) /* handle rcv queue full */
skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
}
/* iucv_process_message_q() - Process outstanding IUCV messages
@ -1438,13 +1443,13 @@ static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
rskb = skb_dequeue(&iucv->backlog_skb_q);
while (rskb) {
IUCV_SKB_CB(rskb)->offset = 0;
if (sock_queue_rcv_skb(sk, rskb)) {
if (__sock_queue_rcv_skb(sk, rskb)) {
/* handle rcv queue full */
skb_queue_head(&iucv->backlog_skb_q,
rskb);
break;
} else {
rskb = skb_dequeue(&iucv->backlog_skb_q);
}
rskb = skb_dequeue(&iucv->backlog_skb_q);
}
if (skb_queue_empty(&iucv->backlog_skb_q)) {
if (!list_empty(&iucv->message_q.list))
@ -2124,12 +2129,17 @@ static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
skb_reset_transport_header(skb);
skb_reset_network_header(skb);
IUCV_SKB_CB(skb)->offset = 0;
if (sk_filter(sk, skb)) {
atomic_inc(&sk->sk_drops); /* skb rejected by filter */
kfree_skb(skb);
return NET_RX_SUCCESS;
}
spin_lock(&iucv->message_q.lock);
if (skb_queue_empty(&iucv->backlog_skb_q)) {
if (sock_queue_rcv_skb(sk, skb)) {
if (__sock_queue_rcv_skb(sk, skb))
/* handle rcv queue full */
skb_queue_tail(&iucv->backlog_skb_q, skb);
}
} else
skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
spin_unlock(&iucv->message_q.lock);