1 files changed, 34 insertions, 20 deletions

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index fc8ad001bc94..4fd861063ed4 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -443,9 +443,14 @@ static ssize_t ppp_read(struct file *file, char __user *buf,
 			 * network traffic (demand mode).
 			 */
 			struct ppp *ppp = PF_TO_PPP(pf);
+
+			ppp_recv_lock(ppp);
 			if (ppp->n_channels == 0 &&
-			    (ppp->flags & SC_LOOP_TRAFFIC) == 0)
+			    (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
+				ppp_recv_unlock(ppp);
 				break;
+			}
+			ppp_recv_unlock(ppp);
 		}
 		ret = -EAGAIN;
 		if (file->f_flags & O_NONBLOCK)
@@ -532,9 +537,12 @@ static unsigned int ppp_poll(struct file *file, poll_table *wait)
 	else if (pf->kind == INTERFACE) {
 		/* see comment in ppp_read */
 		struct ppp *ppp = PF_TO_PPP(pf);
+
+		ppp_recv_lock(ppp);
 		if (ppp->n_channels == 0 &&
 		    (ppp->flags & SC_LOOP_TRAFFIC) == 0)
 			mask |= POLLIN | POLLRDNORM;
+		ppp_recv_unlock(ppp);
 	}
 
 	return mask;
@@ -567,7 +575,7 @@ static int get_filter(void __user *arg, struct sock_filter **p)
 
 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	struct ppp_file *pf = file->private_data;
+	struct ppp_file *pf;
 	struct ppp *ppp;
 	int err = -EFAULT, val, val2, i;
 	struct ppp_idle idle;
@@ -577,9 +585,14 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 
-	if (!pf)
-		return ppp_unattached_ioctl(current->nsproxy->net_ns,
-					pf, file, cmd, arg);
+	mutex_lock(&ppp_mutex);
+
+	pf = file->private_data;
+	if (!pf) {
+		err = ppp_unattached_ioctl(current->nsproxy->net_ns,
+					   pf, file, cmd, arg);
+		goto out;
+	}
 
 	if (cmd == PPPIOCDETACH) {
 		/*
@@ -594,7 +607,6 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		 * this fd and reopening /dev/ppp.
 		 */
 		err = -EINVAL;
-		mutex_lock(&ppp_mutex);
 		if (pf->kind == INTERFACE) {
 			ppp = PF_TO_PPP(pf);
 			rtnl_lock();
@@ -608,15 +620,13 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		} else
 			pr_warn("PPPIOCDETACH file->f_count=%ld\n",
 				atomic_long_read(&file->f_count));
-		mutex_unlock(&ppp_mutex);
-		return err;
+		goto out;
 	}
 
 	if (pf->kind == CHANNEL) {
 		struct channel *pch;
 		struct ppp_channel *chan;
 
-		mutex_lock(&ppp_mutex);
 		pch = PF_TO_CHANNEL(pf);
 
 		switch (cmd) {
@@ -638,17 +648,16 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 				err = chan->ops->ioctl(chan, cmd, arg);
 			up_read(&pch->chan_sem);
 		}
-		mutex_unlock(&ppp_mutex);
-		return err;
+		goto out;
 	}
 
 	if (pf->kind != INTERFACE) {
 		/* can't happen */
 		pr_err("PPP: not interface or channel??\n");
-		return -EINVAL;
+		err = -EINVAL;
+		goto out;
 	}
 
-	mutex_lock(&ppp_mutex);
 	ppp = PF_TO_PPP(pf);
 	switch (cmd) {
 	case PPPIOCSMRU:
@@ -823,7 +832,10 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	default:
 		err = -ENOTTY;
 	}
+
+out:
 	mutex_unlock(&ppp_mutex);
+
 	return err;
 }
 
@@ -836,7 +848,6 @@ static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
 	struct ppp_net *pn;
 	int __user *p = (int __user *)arg;
 
-	mutex_lock(&ppp_mutex);
 	switch (cmd) {
 	case PPPIOCNEWUNIT:
 		/* Create a new ppp unit */
@@ -886,7 +897,7 @@ static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
 	default:
 		err = -ENOTTY;
 	}
-	mutex_unlock(&ppp_mutex);
+
 	return err;
 }
 
@@ -2429,13 +2440,15 @@ ppp_set_compress(struct ppp *ppp, unsigned long arg)
 	unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
 
 	err = -EFAULT;
-	if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
-	    (data.length <= CCP_MAX_OPTION_LENGTH &&
-	     copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
+	if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
+		goto out;
+	if (data.length > CCP_MAX_OPTION_LENGTH)
 		goto out;
+	if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
+		goto out;
+
 	err = -EINVAL;
-	if (data.length > CCP_MAX_OPTION_LENGTH ||
-	    ccp_option[1] < 2 || ccp_option[1] > data.length)
+	if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
 		goto out;
 
 	cp = try_then_request_module(
@@ -2808,6 +2821,7 @@ static struct ppp *ppp_create_interface(struct net *net, int unit,
 
 out2:
 	mutex_unlock(&pn->all_ppp_mutex);
+	rtnl_unlock();
 	free_netdev(dev);
 out1:
 	*retp = ret;