In the Linux kernel, the following vulnerability has been resolved:
ixgbe: fix pci device refcount leak
As the comment of pcigetdomainbusandslot() says, it returns a PCI device with refcount incremented, when finish using it, the caller must decrement the reference count by calling pcidev_put().
In ixgbegetfirstsecondarydevfn() and ixgbex550emahasmii(), pcidevput() is called to avoid leak.