Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7658b36f authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

net: convert in_device.refcnt from atomic_t to refcount_t 



refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid Windsor <dwindsor@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8851ab52

include/linux/inetdevice.h

+6 −5
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/timer.h>

#include <linux/sysctl.h>

#include <linux/rtnetlink.h>

#include <linux/refcount.h>



struct ipv4_devconf {

	void	*sysctl;
@@ -22,7 +23,7 @@ struct ipv4_devconf { 


struct in_device {

	struct net_device	*dev;

	atomic_t		refcnt;

	refcount_t		refcnt;

	int			dead;

	struct in_ifaddr	*ifa_list;	/* IP ifaddr chain		*/
@@ -219,7 +220,7 @@ static inline struct in_device *in_dev_get(const struct net_device *dev) 
	rcu_read_lock();

	in_dev = __in_dev_get_rcu(dev);

	if (in_dev)

		atomic_inc(&in_dev->refcnt);

		refcount_inc(&in_dev->refcnt);

	rcu_read_unlock();

	return in_dev;

}
@@ -240,12 +241,12 @@ void in_dev_finish_destroy(struct in_device *idev); 


static inline void in_dev_put(struct in_device *idev)

{

	if (atomic_dec_and_test(&idev->refcnt))

	if (refcount_dec_and_test(&idev->refcnt))

		in_dev_finish_destroy(idev);

}



#define __in_dev_put(idev)  atomic_dec(&(idev)->refcnt)

#define in_dev_hold(idev)   atomic_inc(&(idev)->refcnt)

#define __in_dev_put(idev)  refcount_dec(&(idev)->refcnt)

#define in_dev_hold(idev)   refcount_inc(&(idev)->refcnt)



#endif /* __KERNEL__ */

net/ipv4/devinet.c

+1 −1
Original line number Diff line number Diff line
@@ -252,7 +252,7 @@ static struct in_device *inetdev_init(struct net_device *dev) 
	/* Reference in_dev->dev */

	dev_hold(dev);

	/* Account for reference dev->ip_ptr (below) */

	in_dev_hold(in_dev);

	refcount_set(&in_dev->refcnt, 1);



	err = devinet_sysctl_register(in_dev);

	if (err) {