[PATCH 03/18] net, l2tp: convert l2tp_session.ref_count from atomic_t to refcount_t
From: Elena Reshetova <elena.reshetova@intel.com>
Date: 2017-03-17 11:13:41
Also in:
bridge, linux-bluetooth, linux-hams, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- net/l2tp/l2tp_core.c | 2 +- net/l2tp/l2tp_core.h | 10 +++++----- 2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 37e9cf3..20ee848 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c@@ -1796,7 +1796,7 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn /* Bump the reference count. The session context is deleted * only when this drops to zero. */ - l2tp_session_inc_refcount(session); + refcount_set(&session->ref_count, 1); l2tp_tunnel_inc_refcount(tunnel); /* Ensure tunnel socket isn't deleted */
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index b942854..568b721 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];
@@ -271,12 +271,12 @@ 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); }
@@ -285,14 +285,14 @@ 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
--
2.7.4