linux/virt/kvm
David Hildenbrand 1563625c71 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2017-04-08 09:30:34 +02:00
..
arm KVM: arm/arm64: Let vcpu thread modify its own active state 2017-03-18 19:14:34 +08:00
async_pf.c KVM: async_pf: avoid recursive flushing of work items 2016-11-19 19:04:17 +01:00
async_pf.h KVM: fix checkpatch.pl errors in kvm/async_pf.h 2015-06-19 17:16:25 +02:00
coalesced_mmio.c KVM: move iodev.h from virt/kvm/ to include/kvm 2015-03-26 21:43:12 +00:00
coalesced_mmio.h KVM: make the declaration of functions within 80 characters 2015-09-14 18:43:19 +02:00
eventfd.c KVM: kvm_io_bus_unregister_dev() should never fail 2017-04-08 09:30:34 +02:00
irqchip.c KVM/ARM Changes for v4.8 - Take 2 2016-08-04 13:59:56 +02:00
Kconfig KVM: remove kvm_vcpu_compatible 2016-06-16 00:05:00 +02:00
kvm_main.c KVM: kvm_io_bus_unregister_dev() should never fail 2017-04-08 09:30:34 +02:00
vfio.c KVM: count number of assigned devices 2015-07-10 13:25:26 +02:00
vfio.h kvm: vfio: fix unregister kvm_device_ops of vfio 2014-10-24 13:30:47 +02:00