From 0b13525c20febcfecccf6fc1db5969727401317d Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Wed, 10 Mar 2021 13:46:26 +0100 Subject: s390/pci: fix leak of PCI device structure In commit 05bc1be6db4b2 ("s390/pci: create zPCI bus") we removed the pci_dev_put() call matching the earlier pci_get_slot() done as part of __zpci_event_availability(). This was based on the wrong understanding that the device_put() done as part of pci_destroy_device() would counter the pci_get_slot() when it only counters the initial reference. This same understanding and existing bad example also lead to not doing a pci_dev_put() in zpci_remove_device(). Since releasing the PCI devices, unlike releasing the PCI slot, does not print any debug message for testing I added one in pci_release_dev(). This revealed that we are indeed leaking the PCI device on PCI hotunplug. Further testing also revealed another missing pci_dev_put() in disable_slot(). Fix this by adding the missing pci_dev_put() in disable_slot() and fix zpci_remove_device() with the correct pci_dev_put() calls. Also instead of calling pci_get_slot() in __zpci_event_availability() to determine if a PCI device is registered and then doing the same again in zpci_remove_device() do this once in zpci_remove_device() which makes sure that the pdev in __zpci_event_availability() is only used for the result of pci_scan_single_device() which does not need a reference count decremnt as its ownership goes to the PCI bus. Also move the check if zdev->zbus->bus is set into zpci_remove_device() since it may be that we're removing a device with devfn != 0 which never had a PCI bus. So we can still set the pdev->error_state to indicate that the device is not usable anymore, add a flag to set the error state. Fixes: 05bc1be6db4b2 ("s390/pci: create zPCI bus") Cc: # 5.8+: e1bff843cde6 s390/pci: remove superfluous zdev->zbus check Cc: # 5.8+: ba764dd703fe s390/pci: refactor zpci_create_device() Cc: # 5.8+ Reviewed-by: Matthew Rosato Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens --- drivers/pci/hotplug/s390_pci_hpc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/pci/hotplug') diff --git a/drivers/pci/hotplug/s390_pci_hpc.c b/drivers/pci/hotplug/s390_pci_hpc.c index c9e790c74051..a047c421debe 100644 --- a/drivers/pci/hotplug/s390_pci_hpc.c +++ b/drivers/pci/hotplug/s390_pci_hpc.c @@ -93,8 +93,9 @@ static int disable_slot(struct hotplug_slot *hotplug_slot) pci_dev_put(pdev); return -EBUSY; } + pci_dev_put(pdev); - zpci_remove_device(zdev); + zpci_remove_device(zdev, false); rc = zpci_disable_device(zdev); if (rc) -- cgit v1.2.3-59-g8ed1b