Commit 271201c0 authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

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: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid Windsor <dwindsor@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1be92460

include/net/addrconf.h

+3 −3
Original line number Diff line number Diff line
@@ -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);

}

include/net/if_inet6.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

net/ipv6/addrconf.c

+1 −1
Original line number Diff line number Diff line
@@ -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);