1 files changed, 34 insertions, 10 deletions

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index a404552555d4..d8e5747ff4e3 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -51,6 +51,7 @@
 #include <asm/unaligned.h>
 #include <net/slhc_vj.h>
 #include <linux/atomic.h>
+#include <linux/refcount.h>
 
 #include <linux/nsproxy.h>
 #include <net/net_namespace.h>
@@ -84,7 +85,7 @@ struct ppp_file {
 	struct sk_buff_head xq;		/* pppd transmit queue */
 	struct sk_buff_head rq;		/* receive queue for pppd */
 	wait_queue_head_t rwait;	/* for poll on reading /dev/ppp */
-	atomic_t	refcnt;		/* # refs (incl /dev/ppp attached) */
+	refcount_t	refcnt;		/* # refs (incl /dev/ppp attached) */
 	int		hdrlen;		/* space to leave for headers */
 	int		index;		/* interface unit / channel number */
 	int		dead;		/* unit/channel has been shut down */
@@ -120,7 +121,7 @@ struct ppp {
 	int		n_channels;	/* how many channels are attached 54 */
 	spinlock_t	rlock;		/* lock for receive side 58 */
 	spinlock_t	wlock;		/* lock for transmit side 5c */
-	int		*xmit_recursion __percpu; /* xmit recursion detect */
+	int __percpu	*xmit_recursion; /* xmit recursion detect */
 	int		mru;		/* max receive unit 60 */
 	unsigned int	flags;		/* control bits 64 */
 	unsigned int	xstate;		/* transmit state bits 68 */
@@ -389,7 +390,7 @@ static int ppp_open(struct inode *inode, struct file *file)
 	/*
 	 * This could (should?) be enforced by the permissions on /dev/ppp.
 	 */
-	if (!capable(CAP_NET_ADMIN))
+	if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
 	return 0;
 }
@@ -408,7 +409,7 @@ static int ppp_release(struct inode *unused, struct file *file)
 				unregister_netdevice(ppp->dev);
 			rtnl_unlock();
 		}
-		if (atomic_dec_and_test(&pf->refcnt)) {
+		if (refcount_dec_and_test(&pf->refcnt)) {
 			switch (pf->kind) {
 			case INTERFACE:
 				ppp_destroy_interface(PF_TO_PPP(pf));
@@ -881,7 +882,7 @@ static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
 		mutex_lock(&pn->all_ppp_mutex);
 		ppp = ppp_find_unit(pn, unit);
 		if (ppp) {
-			atomic_inc(&ppp->file.refcnt);
+			refcount_inc(&ppp->file.refcnt);
 			file->private_data = &ppp->file;
 			err = 0;
 		}
@@ -896,7 +897,7 @@ static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
 		spin_lock_bh(&pn->all_channels_lock);
 		chan = ppp_find_channel(pn, unit);
 		if (chan) {
-			atomic_inc(&chan->file.refcnt);
+			refcount_inc(&chan->file.refcnt);
 			file->private_data = &chan->file;
 			err = 0;
 		}
@@ -959,7 +960,10 @@ static __net_exit void ppp_exit_net(struct net *net)
 	unregister_netdevice_many(&list);
 	rtnl_unlock();
 
+	mutex_destroy(&pn->all_ppp_mutex);
 	idr_destroy(&pn->units_idr);
+	WARN_ON_ONCE(!list_empty(&pn->all_channels));
+	WARN_ON_ONCE(!list_empty(&pn->new_channels));
 }
 
 static struct pernet_operations ppp_net_ops = {
@@ -1339,7 +1343,17 @@ ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
 
 static int ppp_dev_init(struct net_device *dev)
 {
+	struct ppp *ppp;
+
 	netdev_lockdep_set_classes(dev);
+
+	ppp = netdev_priv(dev);
+	/* Let the netdevice take a reference on the ppp file. This ensures
+	 * that ppp_destroy_interface() won't run before the device gets
+	 * unregistered.
+	 */
+	refcount_inc(&ppp->file.refcnt);
+
 	return 0;
 }
 
@@ -1362,6 +1376,15 @@ static void ppp_dev_uninit(struct net_device *dev)
 	wake_up_interruptible(&ppp->file.rwait);
 }
 
+static void ppp_dev_priv_destructor(struct net_device *dev)
+{
+	struct ppp *ppp;
+
+	ppp = netdev_priv(dev);
+	if (refcount_dec_and_test(&ppp->file.refcnt))
+		ppp_destroy_interface(ppp);
+}
+
 static const struct net_device_ops ppp_netdev_ops = {
 	.ndo_init	 = ppp_dev_init,
 	.ndo_uninit      = ppp_dev_uninit,
@@ -1387,6 +1410,7 @@ static void ppp_setup(struct net_device *dev)
 	dev->tx_queue_len = 3;
 	dev->type = ARPHRD_PPP;
 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+	dev->priv_destructor = ppp_dev_priv_destructor;
 	netif_keep_dst(dev);
 }
 
@@ -2656,7 +2680,7 @@ ppp_unregister_channel(struct ppp_channel *chan)
 
 	pch->file.dead = 1;
 	wake_up_interruptible(&pch->file.rwait);
-	if (atomic_dec_and_test(&pch->file.refcnt))
+	if (refcount_dec_and_test(&pch->file.refcnt))
 		ppp_destroy_channel(pch);
 }
 
@@ -3026,7 +3050,7 @@ init_ppp_file(struct ppp_file *pf, int kind)
 	pf->kind = kind;
 	skb_queue_head_init(&pf->xq);
 	skb_queue_head_init(&pf->rq);
-	atomic_set(&pf->refcnt, 1);
+	refcount_set(&pf->refcnt, 1);
 	init_waitqueue_head(&pf->rwait);
 }
 
@@ -3144,7 +3168,7 @@ ppp_connect_channel(struct channel *pch, int unit)
 	list_add_tail(&pch->clist, &ppp->channels);
 	++ppp->n_channels;
 	pch->ppp = ppp;
-	atomic_inc(&ppp->file.refcnt);
+	refcount_inc(&ppp->file.refcnt);
 	ppp_unlock(ppp);
 	ret = 0;
 
@@ -3175,7 +3199,7 @@ ppp_disconnect_channel(struct channel *pch)
 		if (--ppp->n_channels == 0)
 			wake_up_interruptible(&ppp->file.rwait);
 		ppp_unlock(ppp);
-		if (atomic_dec_and_test(&ppp->file.refcnt))
+		if (refcount_dec_and_test(&ppp->file.refcnt))
 			ppp_destroy_interface(ppp);
 		err = 0;
 	}