Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753362AbdGDM6c (ORCPT ); Tue, 4 Jul 2017 08:58:32 -0400 Received: from mga05.intel.com ([192.55.52.43]:29824 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752707AbdGDM63 (ORCPT ); Tue, 4 Jul 2017 08:58:29 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,307,1496127600"; d="scan'208";a="1190388589" 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 32/36] net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t Date: Tue, 4 Jul 2017 15:53:27 +0300 Message-Id: <1499172811-16271-33-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2461 Lines: 70 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 --- include/net/sctp/structs.h | 2 +- net/sctp/transport.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 0dfc5c1..6a0d372 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -735,7 +735,7 @@ struct sctp_transport { struct rhlist_head node; /* Reference counting. */ - atomic_t refcnt; + refcount_t refcnt; /* RTO-Pending : A flag used to track if one of the DATA * chunks sent to this address is currently being * used to compute a RTT. If this flag is 0, diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 7cdd6bc..80a97c8 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -99,7 +99,7 @@ static struct sctp_transport *sctp_transport_init(struct net *net, /* Initialize the 64-bit random nonce sent with heartbeat. */ get_random_bytes(&peer->hb_nonce, sizeof(peer->hb_nonce)); - atomic_set(&peer->refcnt, 1); + refcount_set(&peer->refcnt, 1); return peer; } @@ -172,7 +172,7 @@ static void sctp_transport_destroy_rcu(struct rcu_head *head) */ static void sctp_transport_destroy(struct sctp_transport *transport) { - if (unlikely(atomic_read(&transport->refcnt))) { + if (unlikely(refcount_read(&transport->refcnt))) { WARN(1, "Attempt to destroy undead transport %p!\n", transport); return; } @@ -311,7 +311,7 @@ void sctp_transport_route(struct sctp_transport *transport, /* Hold a reference to a transport. */ int sctp_transport_hold(struct sctp_transport *transport) { - return atomic_add_unless(&transport->refcnt, 1, 0); + return refcount_inc_not_zero(&transport->refcnt); } /* Release a reference to a transport and clean up @@ -319,7 +319,7 @@ int sctp_transport_hold(struct sctp_transport *transport) */ void sctp_transport_put(struct sctp_transport *transport) { - if (atomic_dec_and_test(&transport->refcnt)) + if (refcount_dec_and_test(&transport->refcnt)) sctp_transport_destroy(transport); } -- 2.7.4