Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751611AbdCQMTG (ORCPT ); Fri, 17 Mar 2017 08:19:06 -0400 Received: from mga06.intel.com ([134.134.136.31]:48908 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751035AbdCQMQv (ORCPT ); Fri, 17 Mar 2017 08:16:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,176,1486454400"; d="scan'208";a="78174254" From: Elena Reshetova To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, davem@davemloft.net, linux-x25@vger.kernel.org, linux-sctp@vger.kernel.org, vyasevich@gmail.com, nhorman@tuxdriver.com, linux-hams@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@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, ralf@linux-mips.org, peterz@infradead.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 19/23] net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t Date: Fri, 17 Mar 2017 14:10:42 +0200 Message-Id: <1489752646-8749-20-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489752646-8749-1-git-send-email-elena.reshetova@intel.com> References: <1489752646-8749-1-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 7ee0c26..ac3184e 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -731,7 +731,7 @@ 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 3379668..45a5774 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; } @@ -316,7 +316,7 @@ 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 @@ -324,7 +324,7 @@ 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