Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751465AbdCQMRH (ORCPT ); Fri, 17 Mar 2017 08:17:07 -0400 Received: from mga06.intel.com ([134.134.136.31]:64233 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751074AbdCQMQv (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="78174213" 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 17/23] net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t Date: Fri, 17 Mar 2017 14:10:40 +0200 Message-Id: <1489752646-8749-18-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: 1865 Lines: 59 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/chunk.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index a244db5..106e1d3 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -491,7 +491,7 @@ struct sctp_datamsg { /* Chunks waiting to be submitted to lower layer. */ struct list_head chunks; /* Reference counting. */ - atomic_t refcnt; + refcount_t refcnt; /* When is this message no longer interesting to the peer? */ unsigned long expires_at; /* Did the messenge fail to send? */ diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index e3621cb..30c73ce 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -49,7 +49,7 @@ /* Initialize datamsg from memory. */ static void sctp_datamsg_init(struct sctp_datamsg *msg) { - atomic_set(&msg->refcnt, 1); + refcount_set(&msg->refcnt, 1); msg->send_failed = 0; msg->send_error = 0; msg->can_delay = 1; @@ -136,13 +136,13 @@ static void sctp_datamsg_destroy(struct sctp_datamsg *msg) /* Hold a reference. */ static void sctp_datamsg_hold(struct sctp_datamsg *msg) { - atomic_inc(&msg->refcnt); + refcount_inc(&msg->refcnt); } /* Release a reference. */ void sctp_datamsg_put(struct sctp_datamsg *msg) { - if (atomic_dec_and_test(&msg->refcnt)) + if (refcount_dec_and_test(&msg->refcnt)) sctp_datamsg_destroy(msg); } -- 2.7.4