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Message-Id: <1498650906-12907-5-git-send-email-elena.reshetova@intel.com>
Date: Wed, 28 Jun 2017 14:54:53 +0300
From: Elena Reshetova <elena.reshetova@...el.com>
To: netdev@...r.kernel.org
Cc: bridge@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
kuznet@....inr.ac.ru, jmorris@...ei.org, kaber@...sh.net,
stephen@...workplumber.org, peterz@...radead.org,
keescook@...omium.org, Elena Reshetova <elena.reshetova@...el.com>,
Hans Liljestrand <ishkamiel@...il.com>,
David Windsor <dwindsor@...il.com>
Subject: [PATCH 04/17] net: convert nf_bridge_info.use from atomic_t to refcount_t
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 <elena.reshetova@...el.com>
Signed-off-by: Hans Liljestrand <ishkamiel@...il.com>
Signed-off-by: Kees Cook <keescook@...omium.org>
Signed-off-by: David Windsor <dwindsor@...il.com>
---
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 a098d95..8a26c02 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,
@@ -3593,13 +3593,13 @@ 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 067cf03..2261e51 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
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