Commit 501c8f5e authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'ax25-fixes' 



Duoming Zhou says:

====================
ax25: fix NPD and UAF bugs when detaching ax25 device

There are NPD and UAF bugs when detaching ax25 device, we
use lock and refcount to mitigate these bugs.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 928d6fe9 d01ffb9e

include/net/ax25.h

+10 −0
Original line number Diff line number Diff line
@@ -239,6 +239,7 @@ typedef struct ax25_dev { 
#if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)

	ax25_dama_info		dama;

#endif

	refcount_t		refcount;

} ax25_dev;



typedef struct ax25_cb {
@@ -293,6 +294,15 @@ static __inline__ void ax25_cb_put(ax25_cb *ax25) 
	}

}



#define ax25_dev_hold(__ax25_dev) \

	refcount_inc(&((__ax25_dev)->refcount))



static __inline__ void ax25_dev_put(ax25_dev *ax25_dev)

{

	if (refcount_dec_and_test(&ax25_dev->refcount)) {

		kfree(ax25_dev);

	}

}

static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)

{

	skb->dev      = dev;

net/ax25/af_ax25.c

+8 −3
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ static void ax25_kill_by_device(struct net_device *dev) 
{

	ax25_dev *ax25_dev;

	ax25_cb *s;

	struct sock *sk;



	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)

		return;
@@ -85,13 +86,16 @@ static void ax25_kill_by_device(struct net_device *dev) 
again:

	ax25_for_each(s, &ax25_list) {

		if (s->ax25_dev == ax25_dev) {

			sk = s->sk;

			sock_hold(sk);

			spin_unlock_bh(&ax25_list_lock);

			lock_sock(s->sk);

			lock_sock(sk);

			s->ax25_dev = NULL;

			release_sock(s->sk);

			ax25_dev_put(ax25_dev);

			release_sock(sk);

			ax25_disconnect(s, ENETUNREACH);

			spin_lock_bh(&ax25_list_lock);



			sock_put(sk);

			/* The entry could have been deleted from the

			 * list meanwhile and thus the next pointer is

			 * no longer valid.  Play it safe and restart
@@ -436,6 +440,7 @@ static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg) 
	  }



out_put:

	ax25_dev_put(ax25_dev);

	ax25_cb_put(ax25);

	return ret;

net/ax25/ax25_dev.c

+10 −2
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr) 
	for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)

		if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {

			res = ax25_dev;

			ax25_dev_hold(ax25_dev);

		}

	spin_unlock_bh(&ax25_dev_lock);
@@ -56,6 +57,7 @@ void ax25_dev_device_up(struct net_device *dev) 
		return;

	}



	refcount_set(&ax25_dev->refcount, 1);

	dev->ax25_ptr     = ax25_dev;

	ax25_dev->dev     = dev;

	dev_hold_track(dev, &ax25_dev->dev_tracker, GFP_ATOMIC);
@@ -83,6 +85,7 @@ void ax25_dev_device_up(struct net_device *dev) 
	spin_lock_bh(&ax25_dev_lock);

	ax25_dev->next = ax25_dev_list;

	ax25_dev_list  = ax25_dev;

	ax25_dev_hold(ax25_dev);

	spin_unlock_bh(&ax25_dev_lock);



	ax25_register_dev_sysctl(ax25_dev);
@@ -112,20 +115,22 @@ void ax25_dev_device_down(struct net_device *dev) 


	if ((s = ax25_dev_list) == ax25_dev) {

		ax25_dev_list = s->next;

		ax25_dev_put(ax25_dev);

		spin_unlock_bh(&ax25_dev_lock);

		dev->ax25_ptr = NULL;

		dev_put_track(dev, &ax25_dev->dev_tracker);

		kfree(ax25_dev);

		ax25_dev_put(ax25_dev);

		return;

	}



	while (s != NULL && s->next != NULL) {

		if (s->next == ax25_dev) {

			s->next = ax25_dev->next;

			ax25_dev_put(ax25_dev);

			spin_unlock_bh(&ax25_dev_lock);

			dev->ax25_ptr = NULL;

			dev_put_track(dev, &ax25_dev->dev_tracker);

			kfree(ax25_dev);

			ax25_dev_put(ax25_dev);

			return;

		}
@@ -133,6 +138,7 @@ void ax25_dev_device_down(struct net_device *dev) 
	}

	spin_unlock_bh(&ax25_dev_lock);

	dev->ax25_ptr = NULL;

	ax25_dev_put(ax25_dev);

}



int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
@@ -149,6 +155,7 @@ int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd) 
		if (ax25_dev->forward != NULL)

			return -EINVAL;

		ax25_dev->forward = fwd_dev->dev;

		ax25_dev_put(fwd_dev);

		break;



	case SIOCAX25DELFWD:
@@ -161,6 +168,7 @@ int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd) 
		return -EINVAL;

	}



	ax25_dev_put(ax25_dev);

	return 0;

}

net/ax25/ax25_route.c

+3 −0
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 
	ax25_rt->dev          = ax25_dev->dev;

	ax25_rt->digipeat     = NULL;

	ax25_rt->ip_mode      = ' ';

	ax25_dev_put(ax25_dev);

	if (route->digi_count != 0) {

		if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {

			write_unlock_bh(&ax25_route_lock);
@@ -172,6 +173,7 @@ static int ax25_rt_del(struct ax25_routes_struct *route) 
			}

		}

	}

	ax25_dev_put(ax25_dev);

	write_unlock_bh(&ax25_route_lock);



	return 0;
@@ -214,6 +216,7 @@ static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 
	}



out:

	ax25_dev_put(ax25_dev);

	write_unlock_bh(&ax25_route_lock);

	return err;

}