[PATCH net] ixgbe: fix pci device refcount leak

[PATCH net] ixgbe: fix pci device refcount leak

[Yang Yingliang]

As comment of pci_get_domain_bus_and_slot() says, it returns
a pci device with refcount increment, when finish using it,
the caller must decrement the reference count by calling
pci_dev_put().

In ixgbe_get_first_secondary_devfn() and ixgbe_x550em_a_has_mii(),
pci_dev_put() is called to avoid leak.

Fixes: 8fa10ef01260 ("ixgbe: register a mdiobus")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
index 24aa97f993ca..ed0d6a8f239c 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
@@ -855,9 +855,11 @@ static struct pci_dev *ixgbe_get_first_secondary_devfn(unsigned int devfn)
 	rp_pdev = pci_get_domain_bus_and_slot(0, 0, devfn);
 	if (rp_pdev && rp_pdev->subordinate) {
 		bus = rp_pdev->subordinate->number;
+		pci_dev_put(rp_pdev);
 		return pci_get_domain_bus_and_slot(0, bus, 0);
 	}
 
+	pci_dev_put(rp_pdev);
 	return NULL;
 }
 
@@ -882,6 +884,7 @@ static bool ixgbe_x550em_a_has_mii(struct ixgbe_hw *hw)
 	 * of those two root ports
 	 */
 	func0_pdev = ixgbe_get_first_secondary_devfn(PCI_DEVFN(0x16, 0));
+	pci_dev_put(func0_pdev);
 	if (func0_pdev) {
 		if (func0_pdev == pdev)
 			return true;
@@ -889,6 +892,7 @@ static bool ixgbe_x550em_a_has_mii(struct ixgbe_hw *hw)
 			return false;
 	}
 	func0_pdev = ixgbe_get_first_secondary_devfn(PCI_DEVFN(0x17, 0));
+	pci_dev_put(func0_pdev);
 	if (func0_pdev == pdev)
 		return true;
 
-- 
2.25.1

Re: [PATCH net] ixgbe: fix pci device refcount leak

[Jakub Kicinski]

On Fri, 18 Nov 2022 10:04:45 +0800 Yang Yingliang wrote:
> As comment of pci_get_domain_bus_and_slot() says, it returns
> a pci device with refcount increment, when finish using it,
> the caller must decrement the reference count by calling
> pci_dev_put().
> 
> In ixgbe_get_first_secondary_devfn() and ixgbe_x550em_a_has_mii(),
> pci_dev_put() is called to avoid leak.

here as well the CC list is incomplete.