Commit c0126915 authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

IB/cm: Remove cma_multicast->igmp_joined 



This variable isn't read and written to with proper locking, so it is
racy. Instead of using an unlocked bool use presence in the mc->list

The caller could race rdma_join_multicast with rdma_leave_multicast which
would leak a mc join and cause a use after free of mc.

Instead, do not add the mc to the list until it has completed
initialization, all mcs on the list require leaving.

Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
parent 1215cb7c

drivers/infiniband/core/cma.c

+23 −30
Original line number Diff line number Diff line
@@ -366,7 +366,6 @@ struct cma_multicast { 
	void			*context;

	struct sockaddr_storage	addr;

	struct kref		mcref;

	bool			igmp_joined;

	u8			join_state;

};
@@ -1643,22 +1642,15 @@ static void cma_release_port(struct rdma_id_private *id_priv) 
static void cma_leave_roce_mc_group(struct rdma_id_private *id_priv,

				    struct cma_multicast *mc)

{

	if (mc->igmp_joined) {

		struct rdma_dev_addr *dev_addr =

			&id_priv->id.route.addr.dev_addr;

	struct rdma_dev_addr *dev_addr = &id_priv->id.route.addr.dev_addr;

	struct net_device *ndev = NULL;



	if (dev_addr->bound_dev_if)

			ndev = dev_get_by_index(dev_addr->net,

						dev_addr->bound_dev_if);

		ndev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if);

	if (ndev) {

			cma_igmp_send(ndev,

				      &mc->multicast.ib->rec.mgid,

				      false);

		cma_igmp_send(ndev, &mc->multicast.ib->rec.mgid, false);

		dev_put(ndev);

	}

		mc->igmp_joined = false;

	}

	kref_put(&mc->mcref, release_mc);

}
@@ -4196,8 +4188,6 @@ static int cma_iboe_join_multicast(struct rdma_id_private *id_priv, 
			if (!send_only) {

				err = cma_igmp_send(ndev, &mc->multicast.ib->rec.mgid,

						    true);

				if (!err)

					mc->igmp_joined = true;

			}

		}

	} else {
@@ -4249,26 +4239,29 @@ int rdma_join_multicast(struct rdma_cm_id *id, struct sockaddr *addr, 
	memcpy(&mc->addr, addr, rdma_addr_size(addr));

	mc->context = context;

	mc->id_priv = id_priv;

	mc->igmp_joined = false;

	mc->join_state = join_state;

	spin_lock(&id_priv->lock);

	list_add(&mc->list, &id_priv->mc_list);

	spin_unlock(&id_priv->lock);



	if (rdma_protocol_roce(id->device, id->port_num)) {

		kref_init(&mc->mcref);

		ret = cma_iboe_join_multicast(id_priv, mc);

	} else if (rdma_cap_ib_mcast(id->device, id->port_num))

		if (ret)

			goto out_err;

	} else if (rdma_cap_ib_mcast(id->device, id->port_num)) {

		ret = cma_join_ib_multicast(id_priv, mc);

	else

		if (ret)

			goto out_err;

	} else {

		ret = -ENOSYS;

		goto out_err;

	}



	if (ret) {

		spin_lock_irq(&id_priv->lock);

		list_del(&mc->list);

		spin_unlock_irq(&id_priv->lock);

	spin_lock(&id_priv->lock);

	list_add(&mc->list, &id_priv->mc_list);

	spin_unlock(&id_priv->lock);



	return 0;

out_err:

	kfree(mc);

	}

	return ret;

}

EXPORT_SYMBOL(rdma_join_multicast);

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