net, x25: convert x25_route.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 15:53:19 +03:00 committed by David S. Miller
parent 6c5a1c4a2a
commit 5f9ccf6f38
2 changed files with 5 additions and 4 deletions

View File

@ -11,6 +11,7 @@
#define _X25_H
#include <linux/x25.h>
#include <linux/slab.h>
#include <linux/refcount.h>
#include <net/sock.h>
#define X25_ADDR_LEN 16
@ -129,7 +130,7 @@ struct x25_route {
struct x25_address address;
unsigned int sigdigits;
struct net_device *dev;
atomic_t refcnt;
refcount_t refcnt;
};
struct x25_neigh {
@ -265,12 +266,12 @@ void x25_route_free(void);
static __inline__ void x25_route_hold(struct x25_route *rt)
{
atomic_inc(&rt->refcnt);
refcount_inc(&rt->refcnt);
}
static __inline__ void x25_route_put(struct x25_route *rt)
{
if (atomic_dec_and_test(&rt->refcnt))
if (refcount_dec_and_test(&rt->refcnt))
kfree(rt);
}

View File

@ -55,7 +55,7 @@ static int x25_add_route(struct x25_address *address, unsigned int sigdigits,
rt->sigdigits = sigdigits;
rt->dev = dev;
atomic_set(&rt->refcnt, 1);
refcount_set(&rt->refcnt, 1);
list_add(&rt->node, &x25_route_list);
rc = 0;