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| author | Ursula Braun <braunu@de.ibm.com> | 2008-02-07 18:07:44 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-02-07 18:07:44 -0800 |
| commit | f2a77991a918218be4a3ac78250e7eba2282be59 (patch) | |
| tree | 40bdf696b7d2e83a0335ce1357808b45b41184dc | |
| parent | d44447229e35115675d166b51a52e512c281475c (diff) | |
| download | linux-3.10-f2a77991a918218be4a3ac78250e7eba2282be59.tar.gz linux-3.10-f2a77991a918218be4a3ac78250e7eba2282be59.tar.bz2 linux-3.10-f2a77991a918218be4a3ac78250e7eba2282be59.zip | |
[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>
| -rw-r--r-- | net/iucv/af_iucv.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index b3f5f840d06..fee22caf1ba 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -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)) { |