iommu/vt-d: Fix PCI device refcount leak in dmar_dev_scope_init()

for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. Add the missing
pci_dev_put() for the error path to avoid reference count leak.

Fixes: 2e45528 ("iommu/vt-d: Unify the way to process DMAR device scope array")
Signed-off-by: Xiongfeng Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lu Baolu <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>

Author: fenghusthu

drivers/iommu/intel/dmar.c

@@ -820,6 +820,7 @@ int __init dmar_dev_scope_init(void)
 			info = dmar_alloc_pci_notify_info(dev,
 					BUS_NOTIFY_ADD_DEVICE);
 			if (!info) {
+				pci_dev_put(dev);
 				return dmar_dev_scope_status;
 			} else {
 				dmar_pci_bus_add_dev(info);