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: Elena Reshetova <elena.reshet...@intel.com>
Signed-off-by: Hans Liljestrand <ishkam...@gmail.com>
Signed-off-by: Kees Cook <keesc...@chromium.org>
Signed-off-by: David Windsor <dwind...@gmail.com>
---
include/linux/inetdevice.h | 11 ++++++-----
net/ipv4/devinet.c | 2 +-
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index ee971f3..5cd9671 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -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
*/
@@ -212,7 +213,7 @@ 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;
}
@@ -233,12 +234,12 @@ 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__ */
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index cebedd5..1527146 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -251,7 +251,7 @@ 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) {
--
2.7.4
