net, x25: convert x25_neigh.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/x25.h b/include/net/x25.h
index 1ac14006bf78..2609b57bd459 100644
--- a/include/net/x25.h
+++ b/include/net/x25.h
@@ -142,7 +142,7 @@ struct x25_neigh {
         unsigned long           t20;
         struct timer_list       t20timer;
         unsigned long           global_facil_mask;
-        atomic_t                refcnt;
+        refcount_t              refcnt;
 };
 
 struct x25_sock {
@@ -243,12 +243,12 @@ void x25_link_free(void);
 /* x25_neigh.c */
 static __inline__ void x25_neigh_hold(struct x25_neigh *nb)
 {
-        atomic_inc(&nb->refcnt);
+        refcount_inc(&nb->refcnt);
 }
 
 static __inline__ void x25_neigh_put(struct x25_neigh *nb)
 {
-        if (atomic_dec_and_test(&nb->refcnt))
+        if (refcount_dec_and_test(&nb->refcnt))
                 kfree(nb);
 }