iucv: Remove SKB list assumptions.

Eliminate the assumption that SKBs and SKB list heads can
be cast to eachother in SKB list handling code.

This change also appears to fix a bug since the list->next pointer is
sampled outside of holding the SKB queue lock.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2018-08-22 17:01:51 -07:00
Родитель 4a5a553dde
Коммит 9e733177c7
1 изменённых файлов: 15 добавлений и 26 удалений

Просмотреть файл

@ -1873,30 +1873,26 @@ static void iucv_callback_txdone(struct iucv_path *path,
struct sock *sk = path->private;
struct sk_buff *this = NULL;
struct sk_buff_head *list = &iucv_sk(sk)->send_skb_q;
struct sk_buff *list_skb = list->next;
struct sk_buff *list_skb;
unsigned long flags;
bh_lock_sock(sk);
if (!skb_queue_empty(list)) {
spin_lock_irqsave(&list->lock, flags);
while (list_skb != (struct sk_buff *)list) {
if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
this = list_skb;
break;
}
list_skb = list_skb->next;
spin_lock_irqsave(&list->lock, flags);
skb_queue_walk(list, list_skb) {
if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
this = list_skb;
break;
}
if (this)
__skb_unlink(this, list);
}
if (this)
__skb_unlink(this, list);
spin_unlock_irqrestore(&list->lock, flags);
spin_unlock_irqrestore(&list->lock, flags);
if (this) {
kfree_skb(this);
/* wake up any process waiting for sending */
iucv_sock_wake_msglim(sk);
}
if (this) {
kfree_skb(this);
/* wake up any process waiting for sending */
iucv_sock_wake_msglim(sk);
}
if (sk->sk_state == IUCV_CLOSING) {
@ -2284,11 +2280,7 @@ static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
list = &iucv->send_skb_q;
spin_lock_irqsave(&list->lock, flags);
if (skb_queue_empty(list))
goto out_unlock;
list_skb = list->next;
nskb = list_skb->next;
while (list_skb != (struct sk_buff *)list) {
skb_queue_walk_safe(list, list_skb, nskb) {
if (skb_shinfo(list_skb) == skb_shinfo(skb)) {
switch (n) {
case TX_NOTIFY_OK:
@ -2321,10 +2313,7 @@ static void afiucv_hs_callback_txnotify(struct sk_buff *skb,
}
break;
}
list_skb = nskb;
nskb = nskb->next;
}
out_unlock:
spin_unlock_irqrestore(&list->lock, flags);
if (sk->sk_state == IUCV_CLOSING) {