net, l2tp: convert l2tp_session.ref_count 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/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index da58fad..cdb6e33 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -99,7 +99,7 @@ struct l2tp_session {
int nr_oos_count; /* For OOS recovery */
int nr_oos_count_max;
struct hlist_node hlist; /* Hash list node */
- atomic_t ref_count;
+ refcount_t ref_count;
char name[32]; /* for logging */
char ifname[IFNAMSIZ];
@@ -274,12 +274,12 @@ int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
*/
static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
{
- atomic_inc(&session->ref_count);
+ refcount_inc(&session->ref_count);
}
static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
{
- if (atomic_dec_and_test(&session->ref_count))
+ if (refcount_dec_and_test(&session->ref_count))
l2tp_session_free(session);
}
@@ -288,14 +288,14 @@ static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
do { \
pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
__func__, __LINE__, (_s)->name, \
- atomic_read(&_s->ref_count)); \
+ refcount_read(&_s->ref_count)); \
l2tp_session_inc_refcount_1(_s); \
} while (0)
#define l2tp_session_dec_refcount(_s) \
do { \
pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
__func__, __LINE__, (_s)->name, \
- atomic_read(&_s->ref_count)); \
+ refcount_read(&_s->ref_count)); \
l2tp_session_dec_refcount_1(_s); \
} while (0)
#else
