Niklas Schnelle 437bb839e3 PCI: s390: Fix use-after-free of PCI resources with per-function hotplug ... [ Upstream commit ab90950985 ] On s390 PCI functions may be hotplugged individually even when they belong to a multi-function device. In particular on an SR-IOV device VFs may be removed and later re-added. In commit a50297cf82 ("s390/pci: separate zbus creation from scanning") it was missed however that struct pci_bus and struct zpci_bus's resource list retained a reference to the PCI functions MMIO resources even though those resources are released and freed on hot-unplug. These stale resources may subsequently be claimed when the PCI function re-appears resulting in use-after-free. One idea of fixing this use-after-free in s390 specific code that was investigated was to simply keep resources around from the moment a PCI function first appeared until the whole virtual PCI bus created for a multi-function device disappears. The problem with this however is that due to the requirement of artificial MMIO addreesses (address cookies) extra logic is then needed to keep the address cookies compatible on re-plug. At the same time the MMIO resources semantically belong to the PCI function so tying their lifecycle to the function seems more logical. Instead a simpler approach is to remove the resources of an individually hot-unplugged PCI function from the PCI bus's resource list while keeping the resources of other PCI functions on the PCI bus untouched. This is done by introducing pci_bus_remove_resource() to remove an individual resource. Similarly the resource also needs to be removed from the struct zpci_bus's resource list. It turns out however, that there is really no need to add the MMIO resources to the struct zpci_bus's resource list at all and instead we can simply use the zpci_bar_struct's resource pointer directly. Fixes: a50297cf82 ("s390/pci: separate zbus creation from scanning") Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230306151014.60913-2-schnelle@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-03-22 13:31:24 +01:00
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Makefile	s390/pci: consolidate SR-IOV specific code	2020-09-14 11:38:34 +02:00
pci.c	PCI: s390: Fix use-after-free of PCI resources with per-function hotplug	2023-03-22 13:31:24 +01:00
pci_bus.c	PCI: s390: Fix use-after-free of PCI resources with per-function hotplug	2023-03-22 13:31:24 +01:00
pci_bus.h	PCI: s390: Fix use-after-free of PCI resources with per-function hotplug	2023-03-22 13:31:24 +01:00
pci_clp.c	s390/pci: improve zpci_dev reference counting	2022-05-25 09:57:25 +02:00
pci_debug.c	…
pci_dma.c	dma-mapping updates for Linux 5.15	2021-09-02 10:32:06 -07:00
pci_event.c	s390/pci: improve zpci_dev reference counting	2022-05-25 09:57:25 +02:00
pci_insn.c	s390/pci: use register pair instead of register asm	2021-06-18 16:41:23 +02:00
pci_iov.c	s390/pci: add missing pci_iov.h include	2020-09-16 14:08:47 +02:00
pci_iov.h	s390/pci: consolidate SR-IOV specific code	2020-09-14 11:38:34 +02:00
pci_irq.c	s390/pci: Do not mask MSI[-X] entries on teardown	2021-08-10 11:03:29 +02:00
pci_mmio.c	s390/pci: add missing EX_TABLE entries to __pcistg_mio_inuser()/__pcilg_mio_inuser()	2022-11-03 23:59:13 +09:00
pci_sysfs.c	s390/pci: improve DMA translation init and exit	2021-08-25 11:03:34 +02:00