Messages in this thread Patch in this message | | | Date | Fri, 28 Jul 2023 18:35:07 -0700 | Subject | [PATCH v4 01/29] drm/i915/gvt: Verify pfn is "valid" before dereferencing "struct page" | From | Sean Christopherson <> |
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Check that the pfn found by gfn_to_pfn() is actually backed by "struct page" memory prior to retrieving and dereferencing the page. KVM supports backing guest memory with VM_PFNMAP, VM_IO, etc., and so there is no guarantee the pfn returned by gfn_to_pfn() has an associated "struct page".
Fixes: b901b252b6cf ("drm/i915/gvt: Add 2M huge gtt support") Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> Tested-by: Yongwei Ma <yongwei.ma@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> --- drivers/gpu/drm/i915/gvt/gtt.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c index 4ec85308379a..58b9b316ae46 100644 --- a/drivers/gpu/drm/i915/gvt/gtt.c +++ b/drivers/gpu/drm/i915/gvt/gtt.c @@ -1183,6 +1183,10 @@ static int is_2MB_gtt_possible(struct intel_vgpu *vgpu, pfn = gfn_to_pfn(vgpu->vfio_device.kvm, ops->get_pfn(entry)); if (is_error_noslot_pfn(pfn)) return -EINVAL; + + if (!pfn_valid(pfn)) + return -EINVAL; + return PageTransHuge(pfn_to_page(pfn)); } -- 2.41.0.487.g6d72f3e995-goog
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