Commit 88755e9c authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

net, xfrm: convert xfrm_state.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 5534a51a

include/net/xfrm.h

+5 −4
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/mutex.h>

#include <linux/audit.h>

#include <linux/slab.h>

#include <linux/refcount.h>



#include <net/sock.h>

#include <net/dst.h>
@@ -137,7 +138,7 @@ struct xfrm_state { 
	struct hlist_node	bysrc;

	struct hlist_node	byspi;



	atomic_t		refcnt;

	refcount_t		refcnt;

	spinlock_t		lock;



	struct xfrm_id		id;
@@ -837,18 +838,18 @@ void __xfrm_state_destroy(struct xfrm_state *); 


static inline void __xfrm_state_put(struct xfrm_state *x)

{

	atomic_dec(&x->refcnt);

	refcount_dec(&x->refcnt);

}



static inline void xfrm_state_put(struct xfrm_state *x)

{

	if (atomic_dec_and_test(&x->refcnt))

	if (refcount_dec_and_test(&x->refcnt))

		__xfrm_state_destroy(x);

}



static inline void xfrm_state_hold(struct xfrm_state *x)

{

	atomic_inc(&x->refcnt);

	refcount_inc(&x->refcnt);

}



static inline bool addr_match(const void *token1, const void *token2,

net/xfrm/xfrm_state.c

+2 −2
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ static HLIST_HEAD(xfrm_state_gc_list); 


static inline bool xfrm_state_hold_rcu(struct xfrm_state __rcu *x)

{

	return atomic_inc_not_zero(&x->refcnt);

	return refcount_inc_not_zero(&x->refcnt);

}



static inline unsigned int xfrm_dst_hash(struct net *net,
@@ -558,7 +558,7 @@ struct xfrm_state *xfrm_state_alloc(struct net *net) 


	if (x) {

		write_pnet(&x->xs_net, net);

		atomic_set(&x->refcnt, 1);

		refcount_set(&x->refcnt, 1);

		atomic_set(&x->tunnel_users, 0);

		INIT_LIST_HEAD(&x->km.all);

		INIT_HLIST_NODE(&x->bydst);

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