Commit febca281 authored by Ursula Braun's avatar Ursula Braun Committed by David S. Miller
Browse files

[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: default avatarUrsula Braun <braunu@de.ibm.com>
Acked-by: default avatarFrank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 13fdc9a7

include/net/iucv/af_iucv.h

+1 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ struct iucv_sock { 
	char			dst_user_id[8];

	char			dst_name[8];

	struct list_head	accept_q;

	spinlock_t		accept_q_lock;

	struct sock		*parent;

	struct iucv_path	*path;

	struct sk_buff_head	send_skb_q;

net/iucv/af_iucv.c

+14 −2
Original line number Diff line number Diff line
@@ -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)) {

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