[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>
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index b3f5f84..fee22ca 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1112,24 +1112,31 @@
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)) {
