[AF_IUCV]: broken send_skb_q results in endless loop

A race has been detected in iucv_callback_txdone().
skb_unlink has to be done inside the locked area.

In addition checkings for successful allocations are inserted.

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 2255e3c082ed68d6c493f481b87b136a9b53a943..b3f5f840d067129a78b3ded428607e85c6dc2e18 100644 (file)
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -482,6 +482,10 @@ static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
        /* Create path. */
        iucv->path = iucv_path_alloc(IUCV_QUEUELEN_DEFAULT,
                                     IPRMDATA, GFP_KERNEL);
+       if (!iucv->path) {
+               err = -ENOMEM;
+               goto done;
+       }
        err = iucv_path_connect(iucv->path, &af_iucv_handler,
                                sa->siucv_user_id, NULL, user_data, sk);
        if (err) {
@@ -1094,6 +1098,8 @@ static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
 
 save_message:
        save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
+       if (!save_msg)
+               return;
        save_msg->path = path;
        save_msg->msg = *msg;
 
@@ -1118,10 +1124,10 @@ static void iucv_callback_txdone(struct iucv_path *path,
                        this = list_skb;
                        list_skb = list_skb->next;
                } while (memcmp(&msg->tag, this->cb, 4) && list_skb);
+               __skb_unlink(this, list);
 
                spin_unlock_irqrestore(&list->lock, flags);
 
-               skb_unlink(this, &iucv_sk(sk)->send_skb_q);
                kfree_skb(this);
        }