Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754994AbdCPPeb (ORCPT ); Thu, 16 Mar 2017 11:34:31 -0400 Received: from mga05.intel.com ([192.55.52.43]:62193 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753395AbdCPPcs (ORCPT ); Thu, 16 Mar 2017 11:32:48 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,173,1486454400"; d="scan'208";a="76190879" 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 15/17] net: convert net.passive from atomic_t to refcount_t Date: Thu, 16 Mar 2017 17:29:05 +0200 Message-Id: <1489678147-21404-16-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489678147-21404-1-git-send-email-elena.reshetova@intel.com> References: <1489678147-21404-1-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: 2331 Lines: 74 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/net_namespace.h | 3 ++- net/core/net-sysfs.c | 2 +- net/core/net_namespace.c | 4 ++-- 3 files changed, 5 insertions(+), 4 deletions(-) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index af8fe8a..ec6dcaf 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -5,6 +5,7 @@ #define __NET_NET_NAMESPACE_H #include +#include #include #include #include @@ -45,7 +46,7 @@ struct netns_ipvs; #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) struct net { - atomic_t passive; /* To decided when the network + refcount_t passive; /* To decided when the network * namespace should be freed. */ atomic_t count; /* To decided when the network diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 3945821..d62caad 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1444,7 +1444,7 @@ static void *net_grab_current_ns(void) struct net *ns = current->nsproxy->net_ns; #ifdef CONFIG_NET_NS if (ns) - atomic_inc(&ns->passive); + refcount_inc(&ns->passive); #endif return ns; } diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 652468f..cb981aa 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -283,7 +283,7 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) LIST_HEAD(net_exit_list); atomic_set(&net->count, 1); - atomic_set(&net->passive, 1); + refcount_set(&net->passive, 1); net->dev_base_seq = 1; net->user_ns = user_ns; idr_init(&net->netns_ids); @@ -360,7 +360,7 @@ static void net_free(struct net *net) void net_drop_ns(void *p) { struct net *ns = p; - if (ns && atomic_dec_and_test(&ns->passive)) + if (ns && refcount_dec_and_test(&ns->passive)) net_free(ns); } -- 2.7.4