Commit b780d741 authored by Israel Rukshin's avatar Israel Rukshin Committed by Keith Busch
Browse files

nvme: Fix ctrl use-after-free during sysfs deletion 



In case nvme_sysfs_delete() is called by the user before taking the ctrl
reference count, the ctrl may be freed during the creation and cause the
bug. Take the reference as soon as the controller is externally visible,
which is done by cdev_device_add() in nvme_init_ctrl(). Also take the
reference count at the core layer instead of taking it on each transport
separately.

Signed-off-by: default avatarIsrael Rukshin <israelr@mellanox.com>
Reviewed-by: default avatarMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 253fd4ac

drivers/nvme/host/core.c

+2 −0
Original line number Diff line number Diff line
@@ -4130,6 +4130,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 
	if (ret)

		goto out_release_instance;



	nvme_get_ctrl(ctrl);

	cdev_init(&ctrl->cdev, &nvme_dev_fops);

	ctrl->cdev.owner = ops->module;

	ret = cdev_device_add(&ctrl->cdev, ctrl->device);
@@ -4148,6 +4149,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 


	return 0;

out_free_name:

	nvme_put_ctrl(ctrl);

	kfree_const(ctrl->device->kobj.name);

out_release_instance:

	ida_simple_remove(&nvme_instance_ida, ctrl->instance);

drivers/nvme/host/fc.c

+1 −3
Original line number Diff line number Diff line
@@ -3181,10 +3181,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts, 
		goto fail_ctrl;

	}



	nvme_get_ctrl(&ctrl->ctrl);



	if (!queue_delayed_work(nvme_wq, &ctrl->connect_work, 0)) {

		nvme_put_ctrl(&ctrl->ctrl);

		dev_err(ctrl->ctrl.device,

			"NVME-FC{%d}: failed to schedule initial connect\n",

			ctrl->cnum);
@@ -3209,6 +3206,7 @@ fail_ctrl: 


	/* initiate nvme ctrl ref counting teardown */

	nvme_uninit_ctrl(&ctrl->ctrl);

	nvme_put_ctrl(&ctrl->ctrl);



	/* Remove core ctrl ref. */

	nvme_put_ctrl(&ctrl->ctrl);

drivers/nvme/host/pci.c

+0 −1
Original line number Diff line number Diff line
@@ -2802,7 +2802,6 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	dev_info(dev->ctrl.device, "pci function %s\n", dev_name(&pdev->dev));



	nvme_reset_ctrl(&dev->ctrl);

	nvme_get_ctrl(&dev->ctrl);

	async_schedule(nvme_async_probe, dev);



	return 0;

drivers/nvme/host/rdma.c

+1 −2
Original line number Diff line number Diff line
@@ -2043,8 +2043,6 @@ static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev, 
	dev_info(ctrl->ctrl.device, "new ctrl: NQN \"%s\", addr %pISpcs\n",

		ctrl->ctrl.opts->subsysnqn, &ctrl->addr);



	nvme_get_ctrl(&ctrl->ctrl);



	mutex_lock(&nvme_rdma_ctrl_mutex);

	list_add_tail(&ctrl->list, &nvme_rdma_ctrl_list);

	mutex_unlock(&nvme_rdma_ctrl_mutex);
@@ -2054,6 +2052,7 @@ static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev, 
out_uninit_ctrl:

	nvme_uninit_ctrl(&ctrl->ctrl);

	nvme_put_ctrl(&ctrl->ctrl);

	nvme_put_ctrl(&ctrl->ctrl);

	if (ret > 0)

		ret = -EIO;

	return ERR_PTR(ret);

drivers/nvme/host/tcp.c

+1 −2
Original line number Diff line number Diff line
@@ -2428,8 +2428,6 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev, 
	dev_info(ctrl->ctrl.device, "new ctrl: NQN \"%s\", addr %pISp\n",

		ctrl->ctrl.opts->subsysnqn, &ctrl->addr);



	nvme_get_ctrl(&ctrl->ctrl);



	mutex_lock(&nvme_tcp_ctrl_mutex);

	list_add_tail(&ctrl->list, &nvme_tcp_ctrl_list);

	mutex_unlock(&nvme_tcp_ctrl_mutex);
@@ -2439,6 +2437,7 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev, 
out_uninit_ctrl:

	nvme_uninit_ctrl(&ctrl->ctrl);

	nvme_put_ctrl(&ctrl->ctrl);

	nvme_put_ctrl(&ctrl->ctrl);

	if (ret > 0)

		ret = -EIO;

	return ERR_PTR(ret);

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