CVE-2024-56699

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> s390/pci: Fix potential double remove of hotplug slot<br /> <br /> In commit 6ee600bfbe0f ("s390/pci: remove hotplug slot when releasing the<br /> device") the zpci_exit_slot() was moved from zpci_device_reserved() to<br /> zpci_release_device() with the intention of keeping the hotplug slot<br /> around until the device is actually removed.<br /> <br /> Now zpci_release_device() is only called once all references are<br /> dropped. Since the zPCI subsystem only drops its reference once the<br /> device is in the reserved state it follows that zpci_release_device()<br /> must only deal with devices in the reserved state. Despite that it<br /> contains code to tear down from both configured and standby state. For<br /> the standby case this already includes the removal of the hotplug slot<br /> so would cause a double removal if a device was ever removed in<br /> either configured or standby state.<br /> <br /> Instead of causing a potential double removal in a case that should<br /> never happen explicitly WARN_ON() if a device in non-reserved state is<br /> released and get rid of the dead code cases.