[PATCH v2 0/2] Fix use after free in HPT resizing code and related minor improvements

Serhii Popovych spopovyc at redhat.com
Tue Dec 5 01:36:40 AEDT 2017


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.

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

v2:
 Serhii Popovych: Tested with current 4.15-rc2 as host kernel on P8
                  with same testcase as for v1: no problems so far.

Serhii Popovych (2):
  KVM: PPC: Book3S HV: Drop prepare_done from struct kvm_resize_hpt and
    cleanups
  KVM: PPC: Book3S HV: Fix use after free in case of multiple resize
    requests

 arch/powerpc/kvm/book3s_64_mmu_hv.c | 84 +++++++++++++++++++++++++------------
 1 file changed, 57 insertions(+), 27 deletions(-)

-- 
1.8.3.1



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