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Commit f8978bd9 authored by Leon Romanovsky's avatar Leon Romanovsky Committed by Jason Gunthorpe
Browse files

RDMA/netlink: Fix locking around __ib_get_device_by_index 



Holding locks is mandatory when calling __ib_device_get_by_index,
otherwise there are races during the list iteration with device removal.

Since the locks are static to device.c, __ib_device_get_by_index can
never be called correctly by any user out side the file.

Make the function static and provide a safe function that gets the
correct locks and returns a kref'd pointer. Fix all callers.

Fixes: e5c9469e ("RDMA/netlink: Add nldev device doit implementation")
Fixes: c3f66f7b ("RDMA/netlink: Implement nldev port doit callback")
Fixes: 7d02f605 ("RDMA/netlink: Add nldev port dumpit implementation")
Reviewed-by: default avatarMark Bloch <markb@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 16ba3def

drivers/infiniband/core/core_priv.h

+1 −1
Original line number Diff line number Diff line
@@ -314,7 +314,7 @@ static inline int ib_mad_enforce_security(struct ib_mad_agent_private *map, 
}

#endif



struct ib_device *__ib_device_get_by_index(u32 ifindex);

struct ib_device *ib_device_get_by_index(u32 ifindex);

/* RDMA device netlink */

void nldev_init(void);

void nldev_exit(void);

drivers/infiniband/core/device.c

+17 −1
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ static int ib_device_check_mandatory(struct ib_device *device) 
	return 0;

}



struct ib_device *__ib_device_get_by_index(u32 index)

static struct ib_device *__ib_device_get_by_index(u32 index)

{

	struct ib_device *device;
@@ -145,6 +145,22 @@ struct ib_device *__ib_device_get_by_index(u32 index) 
	return NULL;

}



/*

 * Caller is responsible to return refrerence count by calling put_device()

 */

struct ib_device *ib_device_get_by_index(u32 index)

{

	struct ib_device *device;



	down_read(&lists_rwsem);

	device = __ib_device_get_by_index(index);

	if (device)

		get_device(&device->dev);



	up_read(&lists_rwsem);

	return device;

}



static struct ib_device *__ib_device_get_by_name(const char *name)

{

	struct ib_device *device;

drivers/infiniband/core/nldev.c

+36 −18
Original line number Diff line number Diff line
@@ -142,27 +142,34 @@ static int nldev_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh, 


	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);



	device = __ib_device_get_by_index(index);

	device = ib_device_get_by_index(index);

	if (!device)

		return -EINVAL;



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;

	if (!msg) {

		err = -ENOMEM;

		goto err;

	}



	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,

			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),

			0, 0);



	err = fill_dev_info(msg, device);

	if (err) {

		nlmsg_free(msg);

		return err;

	}

	if (err)

		goto err_free;



	nlmsg_end(msg, nlh);



	put_device(&device->dev);

	return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);



err_free:

	nlmsg_free(msg);

err:

	put_device(&device->dev);

	return err;

}



static int _nldev_get_dumpit(struct ib_device *device,
@@ -220,31 +227,40 @@ static int nldev_port_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh, 
		return -EINVAL;



	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);

	device = __ib_device_get_by_index(index);

	device = ib_device_get_by_index(index);

	if (!device)

		return -EINVAL;



	port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);

	if (!rdma_is_port_valid(device, port))

		return -EINVAL;

	if (!rdma_is_port_valid(device, port)) {

		err = -EINVAL;

		goto err;

	}



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;

	if (!msg) {

		err = -ENOMEM;

		goto err;

	}



	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,

			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),

			0, 0);



	err = fill_port_info(msg, device, port);

	if (err) {

		nlmsg_free(msg);

		return err;

	}

	if (err)

		goto err_free;



	nlmsg_end(msg, nlh);

	put_device(&device->dev);



	return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);



err_free:

	nlmsg_free(msg);

err:

	put_device(&device->dev);

	return err;

}



static int nldev_port_get_dumpit(struct sk_buff *skb,
@@ -265,7 +281,7 @@ static int nldev_port_get_dumpit(struct sk_buff *skb, 
		return -EINVAL;



	ifindex = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);

	device = __ib_device_get_by_index(ifindex);

	device = ib_device_get_by_index(ifindex);

	if (!device)

		return -EINVAL;
@@ -299,7 +315,9 @@ static int nldev_port_get_dumpit(struct sk_buff *skb, 
		nlmsg_end(skb, nlh);

	}



out:	cb->args[0] = idx;

out:

	put_device(&device->dev);

	cb->args[0] = idx;

	return skb->len;

}