Re: [PATCH 0/4] Fix use after free in HPT resizing code and related minor improvements

On Wed, Nov 29, 2017 at 11:38:22AM -0500, Serhii Popovych wrote:

It is possible to trigger use after free during HPT resize
causing host kernel to crash. More details and analysis of
the problem can be found in change with corresponding subject
(KVM: PPC: Book3S HV: Fix use after free in case of multiple
resize requests).

We need some changes to prepare for the fix, especially
make ->error in HPT resize instance single point for
tracking allocation state, improve kvmppc_allocate_hpt()
and kvmppc_free_hpt() so they can be used more safely.

See individual commit description message to get more
information on changes presented.

Serhii Popovych (4):
  KVM: PPC: Book3S HV: Drop prepare_done from struct kvm_resize_hpt and
    cleanups
  KVM: PPC: Book3S HV: Improve kvmppc_allocate_hpt()/kvmppc_free_hpt()
  KVM: PPC: Book3S HV: Fix use after free in case of multiple resize
    requests
  KVM: PPC: Book3S HV: Remove redundant parameter from
    resize_hpt_release()

 arch/powerpc/kvm/book3s_64_mmu_hv.c | 139 +++++++++++++++++++++---------------
 1 file changed, 82 insertions(+), 57 deletions(-)

Paul, these (at least 1-3) fix (another :() host crash bug which can
be triggered by guest and/or userspace actions.  Please merge ASAP.

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