net, bridge: convert net_bridge_vlan.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>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index c18682f..fd9ee73 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -21,6 +21,7 @@
#include <net/ip6_fib.h>
#include <linux/if_vlan.h>
#include <linux/rhashtable.h>
+#include <linux/refcount.h>
#define BR_HASH_BITS 8
#define BR_HASH_SIZE (1 << BR_HASH_BITS)
@@ -127,7 +128,7 @@ struct net_bridge_vlan {
struct net_bridge_port *port;
};
union {
- atomic_t refcnt;
+ refcount_t refcnt;
struct net_bridge_vlan *brvlan;
};
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 26a1a56..233a300 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -158,7 +158,7 @@ static struct net_bridge_vlan *br_vlan_get_master(struct net_bridge *br, u16 vid
if (WARN_ON(!masterv))
return NULL;
}
- atomic_inc(&masterv->refcnt);
+ refcount_inc(&masterv->refcnt);
return masterv;
}
@@ -182,7 +182,7 @@ static void br_vlan_put_master(struct net_bridge_vlan *masterv)
return;
vg = br_vlan_group(masterv->br);
- if (atomic_dec_and_test(&masterv->refcnt)) {
+ if (refcount_dec_and_test(&masterv->refcnt)) {
rhashtable_remove_fast(&vg->vlan_hash,
&masterv->vnode, br_vlan_rht_params);
__vlan_del_list(masterv);
@@ -573,7 +573,7 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
br_err(br, "failed insert local address into bridge forwarding table\n");
return ret;
}
- atomic_inc(&vlan->refcnt);
+ refcount_inc(&vlan->refcnt);
vlan->flags |= BRIDGE_VLAN_INFO_BRENTRY;
vg->num_vlans++;
}
@@ -595,7 +595,7 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
vlan->flags &= ~BRIDGE_VLAN_INFO_PVID;
vlan->br = br;
if (flags & BRIDGE_VLAN_INFO_BRENTRY)
- atomic_set(&vlan->refcnt, 1);
+ refcount_set(&vlan->refcnt, 1);
ret = __vlan_add(vlan, flags);
if (ret) {
free_percpu(vlan->stats);