Commit affa78bc authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

net, ipv6: convert ifacaddr6.aca_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 d3981bc6

include/net/if_inet6.h

+1 −1
Original line number Diff line number Diff line
@@ -147,7 +147,7 @@ struct ifacaddr6 { 
	struct rt6_info		*aca_rt;

	struct ifacaddr6	*aca_next;

	int			aca_users;

	atomic_t		aca_refcnt;

	refcount_t		aca_refcnt;

	unsigned long		aca_cstamp;

	unsigned long		aca_tstamp;

};

net/ipv6/anycast.c

+3 −3
Original line number Diff line number Diff line
@@ -203,12 +203,12 @@ void ipv6_sock_ac_close(struct sock *sk) 


static void aca_get(struct ifacaddr6 *aca)

{

	atomic_inc(&aca->aca_refcnt);

	refcount_inc(&aca->aca_refcnt);

}



static void aca_put(struct ifacaddr6 *ac)

{

	if (atomic_dec_and_test(&ac->aca_refcnt)) {

	if (refcount_dec_and_test(&ac->aca_refcnt)) {

		in6_dev_put(ac->aca_idev);

		dst_release(&ac->aca_rt->dst);

		kfree(ac);
@@ -232,7 +232,7 @@ static struct ifacaddr6 *aca_alloc(struct rt6_info *rt, 
	aca->aca_users = 1;

	/* aca_tstamp should be updated upon changes */

	aca->aca_cstamp = aca->aca_tstamp = jiffies;

	atomic_set(&aca->aca_refcnt, 1);

	refcount_set(&aca->aca_refcnt, 1);



	return aca;

}