Return-Path: Received: from mga01.intel.com ([192.55.52.88]:15687 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752582AbdGDMy2 (ORCPT ); Tue, 4 Jul 2017 08:54:28 -0400 From: Elena Reshetova To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-decnet-user@lists.sourceforge.net, davem@davemloft.net, jmorris@namei.org, kaber@trash.net, yoshfuji@linux-ipv6.org, kuznet@ms2.inr.ac.ru, 3chas3@gmail.com, ralf@linux-mips.org, stephen@networkplumber.org, jchapman@katalix.com, jhs@mojatatu.com, bridge@lists.linux-foundation.org, linux-hams@vger.kernel.org, linux-x25@vger.kernel.org, peterz@infradead.org, keescook@chromium.org, linux-rdma@vger.kernel.org, linux-sctp@vger.kernel.org, vyasevich@gmail.com, nhorman@tuxdriver.com, linux-nfs@vger.kernel.org, zyan@redhat.com, sage@redhat.com, bfields@fieldses.org, jlayton@poochiereds.net, steffen.klassert@secunet.com, herbert@gondor.apana.org.au, santosh.shilimkar@oracle.com, jreuter@yaina.de, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 03/36] net, l2tp: convert l2tp_session.ref_count from atomic_t to refcount_t Date: Tue, 4 Jul 2017 15:52:58 +0300 Message-Id: <1499172811-16271-4-git-send-email-elena.reshetova@intel.com> In-Reply-To: <1499172811-16271-1-git-send-email-elena.reshetova@intel.com> References: <1499172811-16271-1-git-send-email-elena.reshetova@intel.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- 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 203c4aa..b0c2d4a 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1854,7 +1854,7 @@ 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 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 -- 2.7.4