Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753351AbdGDM6P (ORCPT ); Tue, 4 Jul 2017 08:58:15 -0400 Received: from mga01.intel.com ([192.55.52.88]:47351 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752051AbdGDM6L (ORCPT ); Tue, 4 Jul 2017 08:58:11 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,307,1496127600"; d="scan'208";a="1190388514" 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 30/36] net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t Date: Tue, 4 Jul 2017 15:53:25 +0300 Message-Id: <1499172811-16271-31-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: 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 07c11fe..4d7c855 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -496,7 +496,7 @@ 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 81466f6..1323d41 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