net, x25: convert x25_neigh.refcnt 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@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: David S. Miller <davem@davemloft.net>
This commit is contained in:
Reshetova, Elena 2017-07-04 15:53:20 +03:00 committed by David S. Miller
parent 5f9ccf6f38
commit 5534a51ab7
2 changed files with 4 additions and 4 deletions

View File

@ -142,7 +142,7 @@ struct x25_neigh {
unsigned long t20;
struct timer_list t20timer;
unsigned long global_facil_mask;
atomic_t refcnt;
refcount_t refcnt;
};
struct x25_sock {
@ -243,12 +243,12 @@ void x25_link_free(void);
/* x25_neigh.c */
static __inline__ void x25_neigh_hold(struct x25_neigh *nb)
{
atomic_inc(&nb->refcnt);
refcount_inc(&nb->refcnt);
}
static __inline__ void x25_neigh_put(struct x25_neigh *nb)
{
if (atomic_dec_and_test(&nb->refcnt))
if (refcount_dec_and_test(&nb->refcnt))
kfree(nb);
}

View File

@ -266,7 +266,7 @@ void x25_link_device_up(struct net_device *dev)
X25_MASK_PACKET_SIZE |
X25_MASK_WINDOW_SIZE;
nb->t20 = sysctl_x25_restart_request_timeout;
atomic_set(&nb->refcnt, 1);
refcount_set(&nb->refcnt, 1);
write_lock_bh(&x25_neigh_list_lock);
list_add(&nb->node, &x25_neigh_list);