net, xfrm: convert xfrm_policy.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 <[email protected]>
Signed-off-by: Hans Liljestrand <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Signed-off-by: David Windsor <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
This commit is contained in:
Reshetova, Elena 2017-07-04 15:53:22 +03:00 • committed by David S. Miller
commit 850a6212c6
3 changed files with 6 additions and 6 deletions

View file

@ -560,7 +560,7 @@ struct xfrm_policy {
/* This lock only affects elements except for entry. */
rwlock_t lock;
atomic_t refcnt;
refcount_t refcnt;
struct timer_list timer;
struct flow_cache_object flo;
@ -816,14 +816,14 @@ static inline void xfrm_audit_state_icvfail(struct xfrm_state *x,
static inline void xfrm_pol_hold(struct xfrm_policy *policy)
{
if (likely(policy != NULL))
atomic_inc(&policy->refcnt);
refcount_inc(&policy->refcnt);
}
void xfrm_policy_destroy(struct xfrm_policy *policy);
static inline void xfrm_pol_put(struct xfrm_policy *policy)
{
if (atomic_dec_and_test(&policy->refcnt))
if (refcount_dec_and_test(&policy->refcnt))
xfrm_policy_destroy(policy);
}