[AF_IUCV]: defensive programming of iucv_callback_txdone

The loop in iucv_callback_txdone presumes existence of an entry
with msg->tag in the send_skb_q list. In error cases this
assumption might be wrong and might cause an endless loop.
Loop is rewritten to guarantee loop end in case of missing
msg->tag entry in send_skb_q.

Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ursula Braun 2008-02-07 18:07:44 -08:00 committed by David S. Miller
parent d44447229e
commit f2a77991a9

View File

@ -1112,24 +1112,31 @@ static void iucv_callback_txdone(struct iucv_path *path,
struct iucv_message *msg)
{
struct sock *sk = path->private;
struct sk_buff *this;
struct sk_buff *this = NULL;
struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
struct sk_buff *list_skb = list->next;
unsigned long flags;
if (list_skb) {
if (!skb_queue_empty(list)) {
spin_lock_irqsave(&list->lock, flags);
do {
this = list_skb;
while (list_skb != (struct sk_buff *)list) {
if (!memcmp(&msg->tag, list_skb->cb, 4)) {
this = list_skb;
break;
}
list_skb = list_skb->next;
} while (memcmp(&msg->tag, this->cb, 4) && list_skb);
__skb_unlink(this, list);
}
if (this)
__skb_unlink(this, list);
spin_unlock_irqrestore(&list->lock, flags);
kfree_skb(this);
if (this)
kfree_skb(this);
}
if (!this)
printk(KERN_ERR "AF_IUCV msg tag %u not found\n", msg->tag);
if (sk->sk_state == IUCV_CLOSING) {
if (skb_queue_empty(&iucv_sk(sk)->send_skb_q)) {