[PATCH 4.9 54/62] iommu/vt-d: Fix PCI device refcount leak in dmar_dev_scope_init()

Greg Kroah-Hartman
2022-12-05T19:13:42Z

From: Xiongfeng Wang <wangxiongfeng2@huawei.com>

[ 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: 2e4552893038 ("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>
---
drivers/iommu/dmar.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index d8b8cf36de31..fb03616f9ade 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -803,6 +803,7 @@ 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);
--
2.35.1