Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752857AbdGDMzn (ORCPT ); Tue, 4 Jul 2017 08:55:43 -0400 Received: from mga04.intel.com ([192.55.52.120]:16991 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752829AbdGDMzj (ORCPT ); Tue, 4 Jul 2017 08:55:39 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,307,1496127600"; d="scan'208";a="1190387948" 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 13/36] net, lapb: convert lapb_cb.refcnt from atomic_t to refcount_t Date: Tue, 4 Jul 2017 15:53:08 +0300 Message-Id: <1499172811-16271-14-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: 1812 Lines: 66 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/lapb.h | 3 ++- net/lapb/lapb_iface.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/include/net/lapb.h b/include/net/lapb.h index 9510f87..85e7737 100644 --- a/include/net/lapb.h +++ b/include/net/lapb.h @@ -1,6 +1,7 @@ #ifndef _LAPB_H #define _LAPB_H #include +#include #define LAPB_HEADER_LEN 20 /* LAPB over Ethernet + a bit more */ @@ -101,7 +102,7 @@ struct lapb_cb { struct lapb_frame frmr_data; unsigned char frmr_type; - atomic_t refcnt; + refcount_t refcnt; }; /* lapb_iface.c */ diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c index b50b64a..e15314e 100644 --- a/net/lapb/lapb_iface.c +++ b/net/lapb/lapb_iface.c @@ -54,12 +54,12 @@ static void lapb_free_cb(struct lapb_cb *lapb) static __inline__ void lapb_hold(struct lapb_cb *lapb) { - atomic_inc(&lapb->refcnt); + refcount_inc(&lapb->refcnt); } static __inline__ void lapb_put(struct lapb_cb *lapb) { - if (atomic_dec_and_test(&lapb->refcnt)) + if (refcount_dec_and_test(&lapb->refcnt)) lapb_free_cb(lapb); } @@ -136,7 +136,7 @@ static struct lapb_cb *lapb_create_cb(void) lapb->mode = LAPB_DEFAULT_MODE; lapb->window = LAPB_DEFAULT_WINDOW; lapb->state = LAPB_STATE_0; - atomic_set(&lapb->refcnt, 1); + refcount_set(&lapb->refcnt, 1); out: return lapb; } -- 2.7.4