1 files changed, 76 insertions, 80 deletions

diff --git a/drivers/net/pppoe.c b/drivers/net/pppoe.c
index ebfa2967cd68..6f98834e6ace 100644
--- a/drivers/net/pppoe.c
+++ b/drivers/net/pppoe.c
@@ -207,7 +207,7 @@ static inline struct pppox_sock *get_item(unsigned long sid,
 
 static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
 {
-	struct net_device *dev = NULL;
+	struct net_device *dev;
 	int ifindex;
 
 	dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
@@ -218,20 +218,6 @@ static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
 	return get_item(sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote, ifindex);
 }
 
-static inline int set_item(struct pppox_sock *po)
-{
-	int i;
-
-	if (!po)
-		return -EINVAL;
-
-	write_lock_bh(&pppoe_hash_lock);
-	i = __set_item(po);
-	write_unlock_bh(&pppoe_hash_lock);
-
-	return i;
-}
-
 static inline struct pppox_sock *delete_item(unsigned long sid, char *addr, int ifindex)
 {
 	struct pppox_sock *ret;
@@ -255,54 +241,53 @@ static inline struct pppox_sock *delete_item(unsigned long sid, char *addr, int
 static void pppoe_flush_dev(struct net_device *dev)
 {
 	int hash;
-
 	BUG_ON(dev == NULL);
 
-	read_lock_bh(&pppoe_hash_lock);
+	write_lock_bh(&pppoe_hash_lock);
 	for (hash = 0; hash < PPPOE_HASH_SIZE; hash++) {
 		struct pppox_sock *po = item_hash_table[hash];
 
 		while (po != NULL) {
-			if (po->pppoe_dev == dev) {
-				struct sock *sk = sk_pppox(po);
-
-				sock_hold(sk);
-				po->pppoe_dev = NULL;
+			struct sock *sk = sk_pppox(po);
+			if (po->pppoe_dev != dev) {
+				po = po->next;
+				continue;
+			}
+			po->pppoe_dev = NULL;
+			dev_put(dev);
 
-				/* We hold a reference to SK, now drop the
-				 * hash table lock so that we may attempt
-				 * to lock the socket (which can sleep).
-				 */
-				read_unlock_bh(&pppoe_hash_lock);
 
-				lock_sock(sk);
+			/* We always grab the socket lock, followed by the
+			 * pppoe_hash_lock, in that order.  Since we should
+			 * hold the sock lock while doing any unbinding,
+			 * we need to release the lock we're holding.
+			 * Hold a reference to the sock so it doesn't disappear
+			 * as we're jumping between locks.
+			 */
 
-				if (sk->sk_state &
-				    (PPPOX_CONNECTED | PPPOX_BOUND)) {
-					pppox_unbind_sock(sk);
-					dev_put(dev);
-					sk->sk_state = PPPOX_ZOMBIE;
-					sk->sk_state_change(sk);
-				}
+			sock_hold(sk);
 
-				release_sock(sk);
+			write_unlock_bh(&pppoe_hash_lock);
+			lock_sock(sk);
 
-				sock_put(sk);
+			if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
+				pppox_unbind_sock(sk);
+				sk->sk_state = PPPOX_ZOMBIE;
+				sk->sk_state_change(sk);
+			}
 
-				read_lock_bh(&pppoe_hash_lock);
+			release_sock(sk);
+			sock_put(sk);
 
-				/* Now restart from the beginning of this
-				 * hash chain.  We always NULL out pppoe_dev
-				 * so we are guaranteed to make forward
-				 * progress.
-				 */
-				po = item_hash_table[hash];
-				continue;
-			}
-			po = po->next;
+			/* Restart scan at the beginning of this hash chain.
+			 * While the lock was dropped the chain contents may
+			 * have changed.
+			 */
+			write_lock_bh(&pppoe_hash_lock);
+			po = item_hash_table[hash];
 		}
 	}
-	read_unlock_bh(&pppoe_hash_lock);
+	write_unlock_bh(&pppoe_hash_lock);
 }
 
 static int pppoe_device_event(struct notifier_block *this,
@@ -344,10 +329,10 @@ static struct notifier_block pppoe_notifier = {
 static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
 {
 	struct pppox_sock *po = pppox_sk(sk);
-	struct pppox_sock *relay_po = NULL;
+	struct pppox_sock *relay_po;
 
 	if (sk->sk_state & PPPOX_BOUND) {
-		struct pppoe_hdr *ph = (struct pppoe_hdr *) skb->nh.raw;
+		struct pppoe_hdr *ph = pppoe_hdr(skb);
 		int len = ntohs(ph->length);
 		skb_pull_rcsum(skb, sizeof(struct pppoe_hdr));
 		if (pskb_trim_rcsum(skb, len))
@@ -401,7 +386,7 @@ static int pppoe_rcv(struct sk_buff *skb,
 	if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
 		goto out;
 
-	ph = (struct pppoe_hdr *) skb->nh.raw;
+	ph = pppoe_hdr(skb);
 
 	po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
 	if (po != NULL)
@@ -433,7 +418,7 @@ static int pppoe_disc_rcv(struct sk_buff *skb,
 	if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
 		goto out;
 
-	ph = (struct pppoe_hdr *) skb->nh.raw;
+	ph = pppoe_hdr(skb);
 	if (ph->code != PADT_CODE)
 		goto abort;
 
@@ -514,36 +499,49 @@ static int pppoe_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 	struct pppox_sock *po;
-	int error = 0;
 
 	if (!sk)
 		return 0;
 
-	if (sock_flag(sk, SOCK_DEAD))
+	lock_sock(sk);
+	if (sock_flag(sk, SOCK_DEAD)){
+		release_sock(sk);
 		return -EBADF;
+	}
 
 	pppox_unbind_sock(sk);
 
 	/* Signal the death of the socket. */
 	sk->sk_state = PPPOX_DEAD;
 
+
+	/* Write lock on hash lock protects the entire "po" struct from
+	 * concurrent updates via pppoe_flush_dev. The "po" struct should
+	 * be considered part of the hash table contents, thus protected
+	 * by the hash table lock */
+	write_lock_bh(&pppoe_hash_lock);
+
 	po = pppox_sk(sk);
 	if (po->pppoe_pa.sid) {
-		delete_item(po->pppoe_pa.sid, po->pppoe_pa.remote, po->pppoe_ifindex);
+		__delete_item(po->pppoe_pa.sid,
+			      po->pppoe_pa.remote, po->pppoe_ifindex);
 	}
 
-	if (po->pppoe_dev)
+	if (po->pppoe_dev) {
 		dev_put(po->pppoe_dev);
+		po->pppoe_dev = NULL;
+	}
 
-	po->pppoe_dev = NULL;
+	write_unlock_bh(&pppoe_hash_lock);
 
 	sock_orphan(sk);
 	sock->sk = NULL;
 
 	skb_queue_purge(&sk->sk_receive_queue);
+	release_sock(sk);
 	sock_put(sk);
 
-	return error;
+	return 0;
 }
 
 
@@ -599,14 +597,18 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 		po->pppoe_dev = dev;
 		po->pppoe_ifindex = dev->ifindex;
 
-		if (!(dev->flags & IFF_UP))
+		write_lock_bh(&pppoe_hash_lock);
+		if (!(dev->flags & IFF_UP)){
+			write_unlock_bh(&pppoe_hash_lock);
 			goto err_put;
+		}
 
 		memcpy(&po->pppoe_pa,
 		       &sp->sa_addr.pppoe,
 		       sizeof(struct pppoe_addr));
 
-		error = set_item(po);
+		error = __set_item(po);
+		write_unlock_bh(&pppoe_hash_lock);
 		if (error < 0)
 			goto err_put;
 
@@ -762,10 +764,10 @@ static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
 		  struct msghdr *m, size_t total_len)
 {
-	struct sk_buff *skb = NULL;
+	struct sk_buff *skb;
 	struct sock *sk = sock->sk;
 	struct pppox_sock *po = pppox_sk(sk);
-	int error = 0;
+	int error;
 	struct pppoe_hdr hdr;
 	struct pppoe_hdr *ph;
 	struct net_device *dev;
@@ -799,7 +801,7 @@ static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
 
 	/* Reserve space for headers. */
 	skb_reserve(skb, dev->hard_header_len);
-	skb->nh.raw = skb->data;
+	skb_reset_network_header(skb);
 
 	skb->dev = dev;
 
@@ -869,7 +871,8 @@ static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
 			goto abort;
 
 		skb_reserve(skb2, dev->hard_header_len + sizeof(struct pppoe_hdr));
-		memcpy(skb_put(skb2, skb->len), skb->data, skb->len);
+		skb_copy_from_linear_data(skb, skb_put(skb2, skb->len),
+					  skb->len);
 	} else {
 		/* Make a clone so as to not disturb the original skb,
 		 * give dev_queue_xmit something it can free.
@@ -884,7 +887,7 @@ static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
 	memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 	skb2->protocol = __constant_htons(ETH_P_PPP_SES);
 
-	skb2->nh.raw = skb2->data;
+	skb_reset_network_header(skb2);
 
 	skb2->dev = dev;
 
@@ -929,10 +932,8 @@ static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
 		  struct msghdr *m, size_t total_len, int flags)
 {
 	struct sock *sk = sock->sk;
-	struct sk_buff *skb = NULL;
+	struct sk_buff *skb;
 	int error = 0;
-	int len;
-	struct pppoe_hdr *ph = NULL;
 
 	if (sk->sk_state & PPPOX_BOUND) {
 		error = -EIO;
@@ -942,26 +943,21 @@ static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
 	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
 				flags & MSG_DONTWAIT, &error);
 
-	if (error < 0) {
+	if (error < 0)
 		goto end;
-	}
 
 	m->msg_namelen = 0;
 
 	if (skb) {
-		error = 0;
-		ph = (struct pppoe_hdr *) skb->nh.raw;
-		len = ntohs(ph->length);
+		struct pppoe_hdr *ph = pppoe_hdr(skb);
+		const int len = ntohs(ph->length);
 
 		error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
-		if (error < 0)
-			goto do_skb_free;
-		error = len;
+		if (error == 0)
+			error = len;
 	}
 
-do_skb_free:
-	if (skb)
-		kfree_skb(skb);
+	kfree_skb(skb);
 end:
 	return error;
 }
@@ -991,7 +987,7 @@ out:
 
 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
 {
-	struct pppox_sock *po = NULL;
+	struct pppox_sock *po;
 	int i = 0;
 
 	for (; i < PPPOE_HASH_SIZE; i++) {