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: f204e0b8ce ("cxl: Driver code for powernv PCIe based cards for userspace access")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/20221111145440.2426970-2-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Yang Yingliang 2022-11-11 22:54:40 +08:00 committed by Greg Kroah-Hartman
parent 61c80d1c38
commit 02cd3032b1

View File

@ -1164,10 +1164,10 @@ 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;
@ -1176,10 +1176,12 @@ 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:
@ -1667,23 +1669,25 @@ 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: