From d12f3827e04b58f617c43f4d44ad3ad788d852b7 Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Tue, 4 Jul 2017 09:34:59 +0300 Subject: [PATCH] net, ipv6: convert xfrm6_tunnel_spi.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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- net/ipv6/xfrm6_tunnel.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv6/xfrm6_tunnel.c b/net/ipv6/xfrm6_tunnel.c index d7b731a78d09..4e438bc7ee87 100644 --- a/net/ipv6/xfrm6_tunnel.c +++ b/net/ipv6/xfrm6_tunnel.c @@ -59,7 +59,7 @@ struct xfrm6_tunnel_spi { struct hlist_node list_byspi; xfrm_address_t addr; u32 spi; - atomic_t refcnt; + refcount_t refcnt; struct rcu_head rcu_head; }; @@ -160,7 +160,7 @@ static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); x6spi->spi = spi; - atomic_set(&x6spi->refcnt, 1); + refcount_set(&x6spi->refcnt, 1); hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]); @@ -178,7 +178,7 @@ __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) spin_lock_bh(&xfrm6_tunnel_spi_lock); x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); if (x6spi) { - atomic_inc(&x6spi->refcnt); + refcount_inc(&x6spi->refcnt); spi = x6spi->spi; } else spi = __xfrm6_tunnel_alloc_spi(net, saddr); @@ -207,7 +207,7 @@ static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr) list_byaddr) { if (xfrm6_addr_equal(&x6spi->addr, saddr)) { - if (atomic_dec_and_test(&x6spi->refcnt)) { + if (refcount_dec_and_test(&x6spi->refcnt)) { hlist_del_rcu(&x6spi->list_byaddr); hlist_del_rcu(&x6spi->list_byspi); call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);