net, rds: convert rds_ib_device.refcount 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/rds/ib.c b/net/rds/ib.c
index 7a64c8db81abdca2048d24380e3441dd50f12b90..a0954ace37744f41821efa6257d094a1ed7428b7 100644 (file)
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -118,8 +118,8 @@ static void rds_ib_dev_free(struct work_struct *work)
 
 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
 {
-       BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
-       if (atomic_dec_and_test(&rds_ibdev->refcount))
+       BUG_ON(refcount_read(&rds_ibdev->refcount) == 0);
+       if (refcount_dec_and_test(&rds_ibdev->refcount))
                queue_work(rds_wq, &rds_ibdev->free_work);
 }
 
@@ -137,7 +137,7 @@ static void rds_ib_add_one(struct ib_device *device)
                return;
 
        spin_lock_init(&rds_ibdev->spinlock);
-       atomic_set(&rds_ibdev->refcount, 1);
+       refcount_set(&rds_ibdev->refcount, 1);
        INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
 
        rds_ibdev->max_wrs = device->attrs.max_qp_wr;
@@ -205,10 +205,10 @@ static void rds_ib_add_one(struct ib_device *device)
        down_write(&rds_ib_devices_lock);
        list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
        up_write(&rds_ib_devices_lock);
-       atomic_inc(&rds_ibdev->refcount);
+       refcount_inc(&rds_ibdev->refcount);
 
        ib_set_client_data(device, &rds_ib_client, rds_ibdev);
-       atomic_inc(&rds_ibdev->refcount);
+       refcount_inc(&rds_ibdev->refcount);
 
        rds_ib_nodev_connect();
 
@@ -239,7 +239,7 @@ struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
        rcu_read_lock();
        rds_ibdev = ib_get_client_data(device, &rds_ib_client);
        if (rds_ibdev)
-               atomic_inc(&rds_ibdev->refcount);
+               refcount_inc(&rds_ibdev->refcount);
        rcu_read_unlock();
        return rds_ibdev;
 }

diff --git a/net/rds/ib.h b/net/rds/ib.h
index ec550626e221cb80fa5aaec7a00116dc3bd55c5d..bf4822407567044464b594e4e66a81dade3f0ed3 100644 (file)
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -230,7 +230,7 @@ struct rds_ib_device {
        unsigned int            max_initiator_depth;
        unsigned int            max_responder_resources;
        spinlock_t              spinlock;       /* protect the above */
-       atomic_t                refcount;
+       refcount_t              refcount;
        struct work_struct      free_work;
        int                     *vector_load;
 };

diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index 977f69886c0088e7d77d66dd2dd98ecd094b300c..9a3c54e659e9e08430ba4649df65ccfbaea6d939 100644 (file)
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -52,7 +52,7 @@ static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
        list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) {
                list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
                        if (i_ipaddr->ipaddr == ipaddr) {
-                               atomic_inc(&rds_ibdev->refcount);
+                               refcount_inc(&rds_ibdev->refcount);
                                rcu_read_unlock();
                                return rds_ibdev;
                        }
@@ -134,7 +134,7 @@ void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *con
        spin_unlock_irq(&ib_nodev_conns_lock);
 
        ic->rds_ibdev = rds_ibdev;
-       atomic_inc(&rds_ibdev->refcount);
+       refcount_inc(&rds_ibdev->refcount);
 }
 
 void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)