linux/virt/kvm
David Hildenbrand 3358811013 KVM: kvm_io_bus_unregister_dev() should never fail
commit 90db10434b upstream.

No caller currently checks the return value of
kvm_io_bus_unregister_dev(). This is evil, as all callers silently go on
freeing their device. A stale reference will remain in the io_bus,
getting at least used again, when the iobus gets teared down on
kvm_destroy_vm() - leading to use after free errors.

There is nothing the callers could do, except retrying over and over
again.

So let's simply remove the bus altogether, print an error and make
sure no one can access this broken bus again (returning -ENOMEM on any
attempt to access it).

Fixes: e93f8a0f82 ("KVM: convert io_bus to SRCU")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16:
 - Drop changes to kvm_io_bus_get_dev()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
History 2017-07-18 18:40:22 +01:00
..
arm arm/arm64: KVM: Keep elrsr/aisr in sync with software model 2015-05-20 13:25:54 +01:00
assigned-dev.c kvm: Use pci_enable_msix_exact() instead of pci_enable_msix() 2014-04-28 11:13:06 +02:00
async_pf.c KVM: async_pf: do not warn on page allocation failures 2016-03-08 12:15:30 +00:00
async_pf.h KVM: Halt vcpu if page it tries to access is swapped out 2011-01-12 11:21:39 +02:00
coalesced_mmio.c KVM: return an error code in kvm_vm_ioctl_register_coalesced_mmio() 2014-01-30 11:56:09 +01:00
coalesced_mmio.h KVM: Make coalesced mmio use a device per zone 2011-09-25 19:17:57 +03:00
eventfd.c KVM: kvm_io_bus_unregister_dev() should never fail 2017-07-18 18:40:22 +01:00
ioapic.c KVM: x86: always exit on EOIs for interrupts listed in the IOAPIC redir table 2014-09-05 16:36:32 -07:00
ioapic.h kvm: make local functions static 2014-01-08 19:02:58 -02:00
iodev.h KVM: remove in_range from io devices 2009-09-10 08:33:05 +03:00
iommu.c kvm: fix excessive pages un-pinning in kvm_iommu_map error path. 2014-11-05 11:43:13 +00:00
irq_comm.c kvm/irqchip: Speed up KVM_SET_GSI_ROUTING 2014-05-05 16:29:11 +02:00
irqchip.c KVM: irqfd: fix NULL pointer dereference in kvm_irq_map_gsi 2016-08-22 22:38:08 +01:00
Kconfig KVM: async_pf: Provide additional direct page notification 2014-01-30 12:51:38 +01:00
kvm_main.c KVM: kvm_io_bus_unregister_dev() should never fail 2017-07-18 18:40:22 +01:00
vfio.c kvm/vfio: Support for DMA coherent IOMMUs 2014-02-26 11:38:40 -07:00