Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752776AbdF3KJK (ORCPT ); Fri, 30 Jun 2017 06:09:10 -0400 Received: from mga06.intel.com ([134.134.136.31]:15307 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752686AbdF3KJG (ORCPT ); Fri, 30 Jun 2017 06:09:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,285,1496127600"; d="scan'208";a="1188959301" From: Elena Reshetova To: netdev@vger.kernel.org Cc: bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kuznet@ms2.inr.ac.ru, jmorris@namei.org, kaber@trash.net, stephen@networkplumber.org, peterz@infradead.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 11/17] net: convert netpoll_info.refcnt from atomic_t to refcount_t Date: Fri, 30 Jun 2017 13:08:04 +0300 Message-Id: <1498817290-3368-12-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1498817290-3368-1-git-send-email-elena.reshetova@intel.com> References: <1498817290-3368-1-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: 1984 Lines: 69 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/linux/netpoll.h | 3 ++- net/core/netpoll.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index 1828900..27c0aaa 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -11,6 +11,7 @@ #include #include #include +#include union inet_addr { __u32 all[4]; @@ -34,7 +35,7 @@ struct netpoll { }; struct netpoll_info { - atomic_t refcnt; + refcount_t refcnt; struct semaphore dev_lock; diff --git a/net/core/netpoll.c b/net/core/netpoll.c index a835155..d3408a6 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -632,7 +632,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) skb_queue_head_init(&npinfo->txq); INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); - atomic_set(&npinfo->refcnt, 1); + refcount_set(&npinfo->refcnt, 1); ops = np->dev->netdev_ops; if (ops->ndo_netpoll_setup) { @@ -642,7 +642,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) } } else { npinfo = rtnl_dereference(ndev->npinfo); - atomic_inc(&npinfo->refcnt); + refcount_inc(&npinfo->refcnt); } npinfo->netpoll = np; @@ -821,7 +821,7 @@ void __netpoll_cleanup(struct netpoll *np) synchronize_srcu(&netpoll_srcu); - if (atomic_dec_and_test(&npinfo->refcnt)) { + if (refcount_dec_and_test(&npinfo->refcnt)) { const struct net_device_ops *ops; ops = np->dev->netdev_ops; -- 2.7.4