net, ipv6: convert inet6_ifaddr.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 09:34:56 +03:00 committed by David S. Miller
parent 1be9246077
commit 271201c09c
3 changed files with 5 additions and 5 deletions

View File

@ -350,18 +350,18 @@ void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp);
static inline void in6_ifa_put(struct inet6_ifaddr *ifp)
{
if (atomic_dec_and_test(&ifp->refcnt))
if (refcount_dec_and_test(&ifp->refcnt))
inet6_ifa_finish_destroy(ifp);
}
static inline void __in6_ifa_put(struct inet6_ifaddr *ifp)
{
atomic_dec(&ifp->refcnt);
refcount_dec(&ifp->refcnt);
}
static inline void in6_ifa_hold(struct inet6_ifaddr *ifp)
{
atomic_inc(&ifp->refcnt);
refcount_inc(&ifp->refcnt);
}

View File

@ -46,7 +46,7 @@ struct inet6_ifaddr {
/* In seconds, relative to tstamp. Expiry is at tstamp + HZ * lft. */
__u32 valid_lft;
__u32 prefered_lft;
atomic_t refcnt;
refcount_t refcnt;
spinlock_t lock;
int state;

View File

@ -1050,7 +1050,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
ifa->idev = idev;
/* For caller */
in6_ifa_hold(ifa);
refcount_set(&ifa->refcnt, 1);
/* Add to big hash table */
hash = inet6_addr_hash(addr);