This is a note to let you know that I've just added the patch titled
drm/i915/gvt: Verify pfn is "valid" before dereferencing "struct page"
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-gvt-verify-pfn-is-valid-before-dereferencin.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 84b8b9de22b3c5c07b7b4b0be4093a409407976b
Author: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Fri Jul 28 18:35:07 2023 -0700
drm/i915/gvt: Verify pfn is "valid" before dereferencing "struct page"
[ Upstream commit f046923af79158361295ed4f0a588c80b9fdcc1d ]
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@xxxxxxxxx>
Tested-by: Yongwei Ma <yongwei.ma@xxxxxxxxx>
Reviewed-by: Zhi Wang <zhi.a.wang@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230729013535.1070024-2-seanjc@xxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 80c60754a5c1c..92462cd4bf7cc 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1188,6 +1188,10 @@ 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));
}
