netfilter: refcounter conversions

refcount_t type and corresponding API (see include/linux/refcount.h)
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@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

12 files changed, 31 insertions, 31 deletions

diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index e6a2753dff9e..3d2ac71a83ec 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -181,7 +181,7 @@ static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
 
 	if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
 		cp->flags |= IP_VS_CONN_F_HASHED;
-		atomic_inc(&cp->refcnt);
+		refcount_inc(&cp->refcnt);
 		hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
 		ret = 1;
 	} else {
@@ -215,7 +215,7 @@ static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
 	if (cp->flags & IP_VS_CONN_F_HASHED) {
 		hlist_del_rcu(&cp->c_list);
 		cp->flags &= ~IP_VS_CONN_F_HASHED;
-		atomic_dec(&cp->refcnt);
+		refcount_dec(&cp->refcnt);
 		ret = 1;
 	} else
 		ret = 0;
@@ -242,13 +242,13 @@ static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
 	if (cp->flags & IP_VS_CONN_F_HASHED) {
 		ret = false;
 		/* Decrease refcnt and unlink conn only if we are last user */
-		if (atomic_cmpxchg(&cp->refcnt, 1, 0) == 1) {
+		if (refcount_dec_if_one(&cp->refcnt)) {
 			hlist_del_rcu(&cp->c_list);
 			cp->flags &= ~IP_VS_CONN_F_HASHED;
 			ret = true;
 		}
 	} else
-		ret = atomic_read(&cp->refcnt) ? false : true;
+		ret = refcount_read(&cp->refcnt) ? false : true;
 
 	spin_unlock(&cp->lock);
 	ct_write_unlock_bh(hash);
@@ -475,7 +475,7 @@ static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
 void ip_vs_conn_put(struct ip_vs_conn *cp)
 {
 	if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
-	    (atomic_read(&cp->refcnt) == 1) &&
+	    (refcount_read(&cp->refcnt) == 1) &&
 	    !timer_pending(&cp->timer))
 		/* expire connection immediately */
 		__ip_vs_conn_put_notimer(cp);
@@ -617,8 +617,8 @@ ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 		      ip_vs_fwd_tag(cp), cp->state,
-		      cp->flags, atomic_read(&cp->refcnt),
-		      atomic_read(&dest->refcnt));
+		      cp->flags, refcount_read(&cp->refcnt),
+		      refcount_read(&dest->refcnt));
 
 	/* Update the connection counters */
 	if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
@@ -714,8 +714,8 @@ static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 		      ip_vs_fwd_tag(cp), cp->state,
-		      cp->flags, atomic_read(&cp->refcnt),
-		      atomic_read(&dest->refcnt));
+		      cp->flags, refcount_read(&cp->refcnt),
+		      refcount_read(&dest->refcnt));
 
 	/* Update the connection counters */
 	if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
@@ -863,10 +863,10 @@ static void ip_vs_conn_expire(unsigned long data)
 
   expire_later:
 	IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
-		  atomic_read(&cp->refcnt),
+		  refcount_read(&cp->refcnt),
 		  atomic_read(&cp->n_control));
 
-	atomic_inc(&cp->refcnt);
+	refcount_inc(&cp->refcnt);
 	cp->timeout = 60*HZ;
 
 	if (ipvs->sync_state & IP_VS_STATE_MASTER)
@@ -941,7 +941,7 @@ ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
 	 * it in the table, so that other thread run ip_vs_random_dropentry
 	 * but cannot drop this entry.
 	 */
-	atomic_set(&cp->refcnt, 1);
+	refcount_set(&cp->refcnt, 1);
 
 	cp->control = NULL;
 	atomic_set(&cp->n_control, 0);
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 9aaa49025cdc..b4a746d0e39b 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -542,7 +542,7 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
-		      cp->flags, atomic_read(&cp->refcnt));
+		      cp->flags, refcount_read(&cp->refcnt));
 
 	ip_vs_conn_stats(cp, svc);
 	return cp;
@@ -1193,7 +1193,7 @@ struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc,
 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 		      IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
-		      cp->flags, atomic_read(&cp->refcnt));
+		      cp->flags, refcount_read(&cp->refcnt));
 	LeaveFunction(12);
 	return cp;
 }
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 5aeb0dde6ccc..541aa7694775 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -699,7 +699,7 @@ ip_vs_trash_get_dest(struct ip_vs_service *svc, int dest_af,
 			      dest->vfwmark,
 			      IP_VS_DBG_ADDR(dest->af, &dest->addr),
 			      ntohs(dest->port),
-			      atomic_read(&dest->refcnt));
+			      refcount_read(&dest->refcnt));
 		if (dest->af == dest_af &&
 		    ip_vs_addr_equal(dest_af, &dest->addr, daddr) &&
 		    dest->port == dport &&
@@ -934,7 +934,7 @@ ip_vs_new_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest,
 	atomic_set(&dest->activeconns, 0);
 	atomic_set(&dest->inactconns, 0);
 	atomic_set(&dest->persistconns, 0);
-	atomic_set(&dest->refcnt, 1);
+	refcount_set(&dest->refcnt, 1);
 
 	INIT_HLIST_NODE(&dest->d_list);
 	spin_lock_init(&dest->dst_lock);
@@ -998,7 +998,7 @@ ip_vs_add_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest)
 		IP_VS_DBG_BUF(3, "Get destination %s:%u from trash, "
 			      "dest->refcnt=%d, service %u/%s:%u\n",
 			      IP_VS_DBG_ADDR(udest->af, &daddr), ntohs(dport),
-			      atomic_read(&dest->refcnt),
+			      refcount_read(&dest->refcnt),
 			      dest->vfwmark,
 			      IP_VS_DBG_ADDR(svc->af, &dest->vaddr),
 			      ntohs(dest->vport));
@@ -1074,7 +1074,7 @@ static void __ip_vs_del_dest(struct netns_ipvs *ipvs, struct ip_vs_dest *dest,
 	spin_lock_bh(&ipvs->dest_trash_lock);
 	IP_VS_DBG_BUF(3, "Moving dest %s:%u into trash, dest->refcnt=%d\n",
 		      IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port),
-		      atomic_read(&dest->refcnt));
+		      refcount_read(&dest->refcnt));
 	if (list_empty(&ipvs->dest_trash) && !cleanup)
 		mod_timer(&ipvs->dest_trash_timer,
 			  jiffies + (IP_VS_DEST_TRASH_PERIOD >> 1));
@@ -1157,7 +1157,7 @@ static void ip_vs_dest_trash_expire(unsigned long data)
 
 	spin_lock(&ipvs->dest_trash_lock);
 	list_for_each_entry_safe(dest, next, &ipvs->dest_trash, t_list) {
-		if (atomic_read(&dest->refcnt) > 1)
+		if (refcount_read(&dest->refcnt) > 1)
 			continue;
 		if (dest->idle_start) {
 			if (time_before(now, dest->idle_start +
@@ -1545,7 +1545,7 @@ ip_vs_forget_dev(struct ip_vs_dest *dest, struct net_device *dev)
 			      dev->name,
 			      IP_VS_DBG_ADDR(dest->af, &dest->addr),
 			      ntohs(dest->port),
-			      atomic_read(&dest->refcnt));
+			      refcount_read(&dest->refcnt));
 		__ip_vs_dst_cache_reset(dest);
 	}
 	spin_unlock_bh(&dest->dst_lock);
diff --git a/net/netfilter/ipvs/ip_vs_lblc.c b/net/netfilter/ipvs/ip_vs_lblc.c
index 5824927cf8e0..b6aa4a970c6e 100644
--- a/net/netfilter/ipvs/ip_vs_lblc.c
+++ b/net/netfilter/ipvs/ip_vs_lblc.c
@@ -448,7 +448,7 @@ __ip_vs_lblc_schedule(struct ip_vs_service *svc)
 		      IP_VS_DBG_ADDR(least->af, &least->addr),
 		      ntohs(least->port),
 		      atomic_read(&least->activeconns),
-		      atomic_read(&least->refcnt),
+		      refcount_read(&least->refcnt),
 		      atomic_read(&least->weight), loh);
 
 	return least;
diff --git a/net/netfilter/ipvs/ip_vs_lblcr.c b/net/netfilter/ipvs/ip_vs_lblcr.c
index 703f11877bee..c13ff575f9f7 100644
--- a/net/netfilter/ipvs/ip_vs_lblcr.c
+++ b/net/netfilter/ipvs/ip_vs_lblcr.c
@@ -204,7 +204,7 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
 		      IP_VS_DBG_ADDR(least->af, &least->addr),
 		      ntohs(least->port),
 		      atomic_read(&least->activeconns),
-		      atomic_read(&least->refcnt),
+		      refcount_read(&least->refcnt),
 		      atomic_read(&least->weight), loh);
 	return least;
 }
@@ -249,7 +249,7 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
 		      __func__,
 		      IP_VS_DBG_ADDR(most->af, &most->addr), ntohs(most->port),
 		      atomic_read(&most->activeconns),
-		      atomic_read(&most->refcnt),
+		      refcount_read(&most->refcnt),
 		      atomic_read(&most->weight), moh);
 	return most;
 }
@@ -612,7 +612,7 @@ __ip_vs_lblcr_schedule(struct ip_vs_service *svc)
 		      IP_VS_DBG_ADDR(least->af, &least->addr),
 		      ntohs(least->port),
 		      atomic_read(&least->activeconns),
-		      atomic_read(&least->refcnt),
+		      refcount_read(&least->refcnt),
 		      atomic_read(&least->weight), loh);
 
 	return least;
diff --git a/net/netfilter/ipvs/ip_vs_nq.c b/net/netfilter/ipvs/ip_vs_nq.c
index a8b63401e773..7d9d4ac596ca 100644
--- a/net/netfilter/ipvs/ip_vs_nq.c
+++ b/net/netfilter/ipvs/ip_vs_nq.c
@@ -110,7 +110,7 @@ ip_vs_nq_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		      IP_VS_DBG_ADDR(least->af, &least->addr),
 		      ntohs(least->port),
 		      atomic_read(&least->activeconns),
-		      atomic_read(&least->refcnt),
+		      refcount_read(&least->refcnt),
 		      atomic_read(&least->weight), loh);
 
 	return least;
diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c
index d952d67f904d..56f8e4b204ff 100644
--- a/net/netfilter/ipvs/ip_vs_proto_sctp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c
@@ -447,7 +447,7 @@ set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
 				ntohs(cp->cport),
 				sctp_state_name(cp->state),
 				sctp_state_name(next_state),
-				atomic_read(&cp->refcnt));
+				refcount_read(&cp->refcnt));
 		if (dest) {
 			if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
 				(next_state != IP_VS_SCTP_S_ESTABLISHED)) {
diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c
index 5117bcb7d2f0..12dc8d5bc37d 100644
--- a/net/netfilter/ipvs/ip_vs_proto_tcp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c
@@ -557,7 +557,7 @@ set_tcp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
 			      ntohs(cp->cport),
 			      tcp_state_name(cp->state),
 			      tcp_state_name(new_state),
-			      atomic_read(&cp->refcnt));
+			      refcount_read(&cp->refcnt));
 
 		if (dest) {
 			if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
diff --git a/net/netfilter/ipvs/ip_vs_rr.c b/net/netfilter/ipvs/ip_vs_rr.c
index 58bacfc461ee..ee0530d14c5f 100644
--- a/net/netfilter/ipvs/ip_vs_rr.c
+++ b/net/netfilter/ipvs/ip_vs_rr.c
@@ -97,7 +97,7 @@ stop:
 		      "activeconns %d refcnt %d weight %d\n",
 		      IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port),
 		      atomic_read(&dest->activeconns),
-		      atomic_read(&dest->refcnt), atomic_read(&dest->weight));
+		      refcount_read(&dest->refcnt), atomic_read(&dest->weight));
 
 	return dest;
 }
diff --git a/net/netfilter/ipvs/ip_vs_sed.c b/net/netfilter/ipvs/ip_vs_sed.c
index f8e2d00f528b..ab23cf203437 100644
--- a/net/netfilter/ipvs/ip_vs_sed.c
+++ b/net/netfilter/ipvs/ip_vs_sed.c
@@ -111,7 +111,7 @@ ip_vs_sed_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		      IP_VS_DBG_ADDR(least->af, &least->addr),
 		      ntohs(least->port),
 		      atomic_read(&least->activeconns),
-		      atomic_read(&least->refcnt),
+		      refcount_read(&least->refcnt),
 		      atomic_read(&least->weight), loh);
 
 	return least;
diff --git a/net/netfilter/ipvs/ip_vs_wlc.c b/net/netfilter/ipvs/ip_vs_wlc.c
index 6b366fd90554..6add39e0ec20 100644
--- a/net/netfilter/ipvs/ip_vs_wlc.c
+++ b/net/netfilter/ipvs/ip_vs_wlc.c
@@ -83,7 +83,7 @@ ip_vs_wlc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
 		      IP_VS_DBG_ADDR(least->af, &least->addr),
 		      ntohs(least->port),
 		      atomic_read(&least->activeconns),
-		      atomic_read(&least->refcnt),
+		      refcount_read(&least->refcnt),
 		      atomic_read(&least->weight), loh);
 
 	return least;
diff --git a/net/netfilter/ipvs/ip_vs_wrr.c b/net/netfilter/ipvs/ip_vs_wrr.c
index 17e6d4406ca7..62258dd457ac 100644
--- a/net/netfilter/ipvs/ip_vs_wrr.c
+++ b/net/netfilter/ipvs/ip_vs_wrr.c
@@ -218,7 +218,7 @@ found:
 		      "activeconns %d refcnt %d weight %d\n",
 		      IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port),
 		      atomic_read(&dest->activeconns),
-		      atomic_read(&dest->refcnt),
+		      refcount_read(&dest->refcnt),
 		      atomic_read(&dest->weight));
 	mark->cl = dest;