net, calipso: convert calipso_doi.refcount 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>
diff --git a/include/net/calipso.h b/include/net/calipso.h
index b1b30cd..5f95b11 100644
--- a/include/net/calipso.h
+++ b/include/net/calipso.h
@@ -38,7 +38,7 @@
 #include <linux/skbuff.h>
 #include <net/netlabel.h>
 #include <net/request_sock.h>
-#include <linux/atomic.h>
+#include <linux/refcount.h>
 #include <asm/unaligned.h>
 
 /* known doi values */
@@ -57,7 +57,7 @@ struct calipso_doi {
 	u32 doi;
 	u32 type;
 
-	atomic_t refcount;
+	refcount_t refcount;
 	struct list_head list;
 	struct rcu_head rcu;
 };