net, ax25: convert ax25_uid_assoc.refcount 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 15:53:29 +03:00 committed by David S. Miller
parent c638457a7c
commit 07f2282fc6
2 changed files with 5 additions and 5 deletions

View File

@ -11,7 +11,7 @@
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/atomic.h>
#include <linux/refcount.h>
#include <net/neighbour.h>
#include <net/sock.h>
@ -158,7 +158,7 @@ enum {
typedef struct ax25_uid_assoc {
struct hlist_node uid_node;
atomic_t refcount;
refcount_t refcount;
kuid_t uid;
ax25_address call;
} ax25_uid_assoc;
@ -167,11 +167,11 @@ typedef struct ax25_uid_assoc {
hlist_for_each_entry(__ax25, list, uid_node)
#define ax25_uid_hold(ax25) \
atomic_inc(&((ax25)->refcount))
refcount_inc(&((ax25)->refcount))
static inline void ax25_uid_put(ax25_uid_assoc *assoc)
{
if (atomic_dec_and_test(&assoc->refcount)) {
if (refcount_dec_and_test(&assoc->refcount)) {
kfree(assoc);
}
}

View File

@ -107,7 +107,7 @@ int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
return -ENOMEM;
atomic_set(&ax25_uid->refcount, 1);
refcount_set(&ax25_uid->refcount, 1);
ax25_uid->uid = sax25_kuid;
ax25_uid->call = sax->sax25_call;