37 lines
1.3 KiB
Diff
37 lines
1.3 KiB
Diff
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x86/HVM: restrict HVMOP_set_mem_type
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Permitting arbitrary type changes here has the potential of creating
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present P2M (and hence EPT/NPT/IOMMU) entries pointing to an invalid
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MFN (INVALID_MFN truncated to the respective hardware structure field's
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width). This would become a problem the latest when something real sat
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at the end of the physical address space; I'm suspecting though that
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other things might break with such bogus entries.
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Along with that drop a bogus (and otherwise becoming stale) log
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message.
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Afaict the similar operation in p2m_set_mem_access() is safe.
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This is XSA-92.
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Signed-off-by: Jan Beulich <jbeulich@suse.com>
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Reviewed-by: Tim Deegan <tim@xen.org>
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--- a/xen/arch/x86/hvm/hvm.c
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+++ b/xen/arch/x86/hvm/hvm.c
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@@ -4410,12 +4410,10 @@ long do_hvm_op(unsigned long op, XEN_GUE
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rc = -EINVAL;
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goto param_fail4;
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}
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- if ( p2m_is_grant(t) )
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+ if ( !p2m_is_ram(t) &&
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+ (!p2m_is_hole(t) || a.hvmmem_type != HVMMEM_mmio_dm) )
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{
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put_gfn(d, pfn);
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- gdprintk(XENLOG_WARNING,
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- "type for pfn %#lx changed to grant while "
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- "we were working?\n", pfn);
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goto param_fail4;
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}
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else
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