Commit 8bf03f55 authored by Yang Yingliang's avatar Yang Yingliang Committed by Michael Ellerman
Browse files

cxl: fix possible null-ptr-deref in cxl_pci_init_afu|adapter() 



If device_register() fails in cxl_pci_afu|adapter(), the device
is not added, device_unregister() can not be called in the error
path, otherwise it will cause a null-ptr-deref because of removing
not added device.

As comment of device_register() says, it should use put_device() to give
up the reference in the error path. So split device_unregister() into
device_del() and put_device(), then goes to put dev when register fails.

Fixes: f204e0b8 ("cxl: Driver code for powernv PCIe based cards for userspace access")
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Acked-by: default avatarAndrew Donnellan <ajd@linux.ibm.com>
Acked-by: default avatarFrederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221111145440.2426970-2-yangyingliang@huawei.com
parent f949ccee

drivers/misc/cxl/pci.c

+12 −8
Original line number Diff line number Diff line
@@ -1165,10 +1165,10 @@ static int pci_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev) 
	 * if it returns an error!

	 */

	if ((rc = cxl_register_afu(afu)))

		goto err_put1;

		goto err_put_dev;



	if ((rc = cxl_sysfs_afu_add(afu)))

		goto err_put1;

		goto err_del_dev;



	adapter->afu[afu->slice] = afu;
@@ -1177,10 +1177,12 @@ static int pci_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev) 


	return 0;



err_put1:

err_del_dev:

	device_del(&afu->dev);

err_put_dev:

	pci_deconfigure_afu(afu);

	cxl_debugfs_afu_remove(afu);

	device_unregister(&afu->dev);

	put_device(&afu->dev);

	return rc;



err_free_native:
@@ -1668,23 +1670,25 @@ static struct cxl *cxl_pci_init_adapter(struct pci_dev *dev) 
	 * even if it returns an error!

	 */

	if ((rc = cxl_register_adapter(adapter)))

		goto err_put1;

		goto err_put_dev;



	if ((rc = cxl_sysfs_adapter_add(adapter)))

		goto err_put1;

		goto err_del_dev;



	/* Release the context lock as adapter is configured */

	cxl_adapter_context_unlock(adapter);



	return adapter;



err_put1:

err_del_dev:

	device_del(&adapter->dev);

err_put_dev:

	/* This should mirror cxl_remove_adapter, except without the

	 * sysfs parts

	 */

	cxl_debugfs_adapter_remove(adapter);

	cxl_deconfigure_adapter(adapter);

	device_unregister(&adapter->dev);

	put_device(&adapter->dev);

	return ERR_PTR(rc);



err_release: