In the Linux kernel, the following vulnerability has been resolved: ixgbe: fix pci device refcount leak As the comment of pci_get_domain_bus_and_slot() says, it returns a PCI device with refcount incremented, 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.
https://git.kernel.org/stable/c/c49996c6aa03590e4ef5add8772cb6068d99fd59
https://git.kernel.org/stable/c/b93fb4405fcb5112c5739c5349afb52ec7f15c07
https://git.kernel.org/stable/c/53cefa802f070d46c0c518f4865be2c749818a18
https://git.kernel.org/stable/c/4c93422a54cd6a349988f42e1c6bf082cf4ea9d8
https://git.kernel.org/stable/c/112df4cd2b09acd64bcd18f5ef83ba5d07b34bf0