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 <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 15:53:22 +03:00 committed by David S. Miller
parent 88755e9c7c
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);
}

View File

@ -2177,7 +2177,7 @@ static int pfkey_xfrm_policy2msg(struct sk_buff *skb, const struct xfrm_policy *
}
hdr->sadb_msg_len = size / sizeof(uint64_t);
hdr->sadb_msg_reserved = atomic_read(&xp->refcnt);
hdr->sadb_msg_reserved = refcount_read(&xp->refcnt);
return 0;
}

View File

@ -62,7 +62,7 @@ static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
{
return atomic_inc_not_zero(&policy->refcnt);
return refcount_inc_not_zero(&policy->refcnt);
}
static inline bool
@ -292,7 +292,7 @@ struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
INIT_HLIST_NODE(&policy->bydst);
INIT_HLIST_NODE(&policy->byidx);
rwlock_init(&policy->lock);
atomic_set(&policy->refcnt, 1);
refcount_set(&policy->refcnt, 1);
skb_queue_head_init(&policy->polq.hold_queue);
setup_timer(&policy->timer, xfrm_policy_timer,
(unsigned long)policy);