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authorUrsula Braun <braunu@de.ibm.com>2007-07-15 04:04:25 +0200
committerDavid S. Miller <davem@davemloft.net>2007-07-15 04:04:25 +0200
commitfebca281f677a775c61cd0572c2f35e4ead9e7d5 (patch)
tree64a58deba476ff3dbc7468d6d2e8e33e1351bf68 /net/iucv
parent[AF_IUCV]: Avoid deadlock between iucv_path_connect and tasklet. (diff)
downloadlinux-febca281f677a775c61cd0572c2f35e4ead9e7d5.tar.xz
linux-febca281f677a775c61cd0572c2f35e4ead9e7d5.zip
[AF_IUCV]: Add lock when updating accept_q
The accept_queue of an af_iucv socket will be corrupted, if adding and deleting of entries in this queue occurs at the same time (connect request from one client, while accept call is processed for another client). Solution: add locking when updating accept_q Signed-off-by: Ursula Braun <braunu@de.ibm.com> Acked-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/iucv')
-rw-r--r--net/iucv/af_iucv.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index d9e9ddb8eac5..53ae14c35f70 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -219,6 +219,7 @@ static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
sock_init_data(sock, sk);
INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
+ spin_lock_init(&iucv_sk(sk)->accept_q_lock);
skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
iucv_sk(sk)->send_tag = 0;
@@ -274,15 +275,25 @@ void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
{
+ unsigned long flags;
+ struct iucv_sock *par = iucv_sk(parent);
+
sock_hold(sk);
- list_add_tail(&iucv_sk(sk)->accept_q, &iucv_sk(parent)->accept_q);
+ spin_lock_irqsave(&par->accept_q_lock, flags);
+ list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
+ spin_unlock_irqrestore(&par->accept_q_lock, flags);
iucv_sk(sk)->parent = parent;
parent->sk_ack_backlog++;
}
void iucv_accept_unlink(struct sock *sk)
{
+ unsigned long flags;
+ struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);
+
+ spin_lock_irqsave(&par->accept_q_lock, flags);
list_del_init(&iucv_sk(sk)->accept_q);
+ spin_unlock_irqrestore(&par->accept_q_lock, flags);
iucv_sk(sk)->parent->sk_ack_backlog--;
iucv_sk(sk)->parent = NULL;
sock_put(sk);
@@ -298,8 +309,8 @@ struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
lock_sock(sk);
if (sk->sk_state == IUCV_CLOSED) {
- release_sock(sk);
iucv_accept_unlink(sk);
+ release_sock(sk);
continue;
}
@@ -879,6 +890,7 @@ static int iucv_callback_connreq(struct iucv_path *path,
/* Find out if this path belongs to af_iucv. */
read_lock(&iucv_sk_list.lock);
iucv = NULL;
+ sk = NULL;
sk_for_each(sk, node, &iucv_sk_list.head)
if (sk->sk_state == IUCV_LISTEN &&
!memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {