Re: [PATCH 1/3] KVM: Destroy I/O bus devices on unregister failure _after_ sync'ing SRCU

From: Jim Mattson
Date: Thu Apr 15 2021 - 17:50:22 EST


On Mon, Apr 12, 2021 at 3:21 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> If allocating a new instance of an I/O bus fails when unregistering a
> device, wait to destroy the device until after all readers are guaranteed
> to see the new null bus. Destroying devices before the bus is nullified
> could lead to use-after-free since readers expect the devices on their
> reference of the bus to remain valid.
>
> Fixes: f65886606c2d ("KVM: fix memory leak in kvm_io_bus_unregister_dev()")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>