Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754716AbdCPP3a (ORCPT ); Thu, 16 Mar 2017 11:29:30 -0400 Received: from mga05.intel.com ([192.55.52.43]:13711 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752282AbdCPP3Y (ORCPT ); Thu, 16 Mar 2017 11:29:24 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,173,1486454400"; d="scan'208";a="76190338" 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 03/17] net: convert nf_bridge_info.use from atomic_t to refcount_t Date: Thu, 16 Mar 2017 17:28:53 +0200 Message-Id: <1489678147-21404-4-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: 2761 Lines: 79 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/skbuff.h | 6 +++--- include/net/netfilter/br_netfilter.h | 2 +- net/bridge/br_netfilter_hooks.c | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 4bcb75f..957a2b0 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -250,7 +250,7 @@ struct nf_conntrack { #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) struct nf_bridge_info { - atomic_t use; + refcount_t use; enum { BRNF_PROTO_UNCHANGED, BRNF_PROTO_8021Q, @@ -3589,13 +3589,13 @@ static inline void nf_conntrack_get(struct nf_conntrack *nfct) #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) { - if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) + if (nf_bridge && refcount_dec_and_test(&nf_bridge->use)) kfree(nf_bridge); } static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) { if (nf_bridge) - atomic_inc(&nf_bridge->use); + refcount_inc(&nf_bridge->use); } #endif /* CONFIG_BRIDGE_NETFILTER */ static inline void nf_reset(struct sk_buff *skb) diff --git a/include/net/netfilter/br_netfilter.h b/include/net/netfilter/br_netfilter.h index 0b0c35c..925524e 100644 --- a/include/net/netfilter/br_netfilter.h +++ b/include/net/netfilter/br_netfilter.h @@ -8,7 +8,7 @@ static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb) skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC); if (likely(skb->nf_bridge)) - atomic_set(&(skb->nf_bridge->use), 1); + refcount_set(&(skb->nf_bridge->use), 1); return skb->nf_bridge; } diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 52739e6..ac04135 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -149,12 +149,12 @@ static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb) { struct nf_bridge_info *nf_bridge = skb->nf_bridge; - if (atomic_read(&nf_bridge->use) > 1) { + if (refcount_read(&nf_bridge->use) > 1) { struct nf_bridge_info *tmp = nf_bridge_alloc(skb); if (tmp) { memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info)); - atomic_set(&tmp->use, 1); + refcount_set(&tmp->use, 1); } nf_bridge_put(nf_bridge); nf_bridge = tmp; -- 2.7.4