Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 53869ceb authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

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: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid Windsor <dwindsor@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6343944b

include/linux/skbuff.h

+3 −3
Original line number Diff line number Diff line
@@ -252,7 +252,7 @@ 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)

include/net/netfilter/br_netfilter.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

}

net/bridge/br_netfilter_hooks.c

+2 −2
Original line number Diff line number Diff line
@@ -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;