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authorReshetova, Elena <elena.reshetova@intel.com>2017-06-30 13:08:03 +0300
committerDavid S. Miller <davem@davemloft.net>2017-07-01 17:39:08 +0300
commit7658b36f1b3122c298213eed344f622e836b281b (patch)
treeef9e9db6bba08079998fd5e30d3748b392603256
parent8851ab526791530d00bbbd0952512d68684a44b8 (diff)
downloadlinux-7658b36f1b3122c298213eed344f622e836b281b.tar.xz
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: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/inetdevice.h11
-rw-r--r--net/ipv4/devinet.c2
2 files changed, 7 insertions, 6 deletions
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index e7c04c4e4bcd..fb3f809e34e4 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 */
@@ -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__ */
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index a7dd088d5fc9..38d9af9b917c 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -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) {