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@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
include/net/neighbour.h | 6 +++---
net/core/neighbour.c | 8 ++++----
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index c5f6d51..83d1e9f 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -77,7 +77,7 @@ struct neigh_parms {
void *sysctl_table;
int dead;
- atomic_t refcnt;
+ refcount_t refcnt;
struct rcu_head rcu_head;
int reachable_time;
@@ -395,12 +395,12 @@ void neigh_sysctl_unregister(struct neigh_parms *p);
static inline void __neigh_parms_put(struct neigh_parms *parms)
{
- atomic_dec(&parms->refcnt);
+ refcount_dec(&parms->refcnt);
}
static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
{
- atomic_inc(&parms->refcnt);
+ refcount_inc(&parms->refcnt);
return parms;
}
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index bc52190..24afede 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -674,7 +674,7 @@ static void neigh_parms_destroy(struct neigh_parms *parms);
static inline void neigh_parms_put(struct neigh_parms *parms)
{
- if (atomic_dec_and_test(&parms->refcnt))
+ if (refcount_dec_and_test(&parms->refcnt))
neigh_parms_destroy(parms);
}
@@ -1444,7 +1444,7 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
p = kmemdup(&tbl->parms, sizeof(*p), GFP_KERNEL);
if (p) {
p->tbl = tbl;
- atomic_set(&p->refcnt, 1);
+ refcount_set(&p->refcnt, 1);
p->reachable_time =
neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
dev_hold(dev);
@@ -1507,7 +1507,7 @@ void neigh_table_init(int index, struct neigh_table *tbl)
INIT_LIST_HEAD(&tbl->parms_list);
list_add(&tbl->parms.list, &tbl->parms_list);
write_pnet(&tbl->parms.net, &init_net);
- atomic_set(&tbl->parms.refcnt, 1);
+ refcount_set(&tbl->parms.refcnt, 1);
tbl->parms.reachable_time =
neigh_rand_reach_time(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME));
@@ -1758,7 +1758,7 @@ static int neightbl_fill_parms(struct sk_buff *skb, struct neigh_parms *parms)
if ((parms->dev &&
nla_put_u32(skb, NDTPA_IFINDEX, parms->dev->ifindex)) ||
- nla_put_u32(skb, NDTPA_REFCNT, atomic_read(&parms->refcnt)) ||
+ nla_put_u32(skb, NDTPA_REFCNT, refcount_read(&parms->refcnt)) ||
nla_put_u32(skb, NDTPA_QUEUE_LENBYTES,
NEIGH_VAR(parms, QUEUE_LEN_BYTES)) ||
/* approximative value for deprecated QUEUE_LEN (in packets) */
--
2.7.4
