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

[ Upstream commit 4bedbbd782ebbe7287231fea862c158d4f08a9e3 ]

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: 6abf2db1f901 ("iommu/vt-d: Unify the way to process DMAR device scope array")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Link: https://lore.kernel.org/r/20221121113649.190393-3-wangxiongfeng2@huawei.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 9f881fc102f73215f4e533f4868b2fd8da3b7916..36900d65386fc8d2894eeadb205b1bc614bb2fcc 100644 (file)
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -794,6 +794,7 @@ 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);