net: convert neigh_params.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>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index e5ee739d2b8c..afc39e3a3f7c 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -77,7 +77,7 @@ struct neigh_parms {
         void    *sysctl_table;
 
         int dead;
-        atomic_t refcnt;
+        refcount_t refcnt;
         struct rcu_head rcu_head;
 
         int     reachable_time;
@@ -396,12 +396,12 @@ void neigh_sysctl_unregister(struct neigh_parms *p);
 
 static inline void __neigh_parms_put(struct neigh_parms *parms)
 {
-        atomic_dec(&parms->refcnt);
+        refcount_dec(&parms->refcnt);
 }
 
 static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
 {
-        atomic_inc(&parms->refcnt);
+        refcount_inc(&parms->refcnt);
         return parms;
 }