[PATCH 6.0 109/124] iommu/vt-d: Fix PCI device refcount leak in has_external_pci()

Greg Kroah-Hartman
2022-12-05T19:27:39Z

From: Xiongfeng Wang <wangxiongfeng2@huawei.com>

[ Upstream commit afca9e19cc720bfafc75dc5ce429c185ca93f31d ]

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() before 'return true' to avoid reference count leak.

Fixes: 89a6079df791 ("iommu/vt-d: Force IOMMU on for platform opt in hint")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Link: https://lore.kernel.org/r/20221121113649.190393-2-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/intel/iommu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index e47700674978..412b106d2a39 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3844,8 +3844,10 @@ static inline bool has_external_pci(void)
struct pci_dev *pdev = NULL;

for_each_pci_dev(pdev)
- if (pdev->external_facing)
+ if (pdev->external_facing) {
+ pci_dev_put(pdev);
return true;
+ }

return false;
}
--
2.35.1