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OvmfPkg/MemEncryptSevLib: Fix address overflow during PVALIDATE 

The struct used for GHCB-based page-state change requests uses a 40-bit
bit-field for the GFN, which is shifted by PAGE_SHIFT to generate a
64-bit address. However, anything beyond 40-bits simply gets shifted off
when doing this, which will cause issues when dealing with 1TB+
addresses. Fix this by casting the 40-bit GFN values to 64-bit ones
prior to shifting it by PAGE_SHIFT.

Fixes: ade62c18f4 ("OvmfPkg/MemEncryptSevLib: add support to validate system RAM")
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-Id: <20231115175153.813213-1-michael.roth@amd.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Michael Roth 2023-11-15 11:51:53 -06:00 committed by mergify[bot]
parent 7eb5040607
commit e8c23d1e27
1 changed files with 3 additions and 2 deletions
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5
OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChangeInternal.c
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@ -78,13 +78,14 @@ PvalidateRange (
IN BOOLEAN Validate
)
{
UINTN Address, RmpPageSize, Ret, i;
UINTN RmpPageSize, Ret, i;
EFI_PHYSICAL_ADDRESS Address;
for ( ; StartIndex <= EndIndex; StartIndex++) {
//
// Get the address and the page size from the Info.
//
Address = Info->Entry[StartIndex].GuestFrameNumber << EFI_PAGE_SHIFT;
Address = ((EFI_PHYSICAL_ADDRESS)Info->Entry[StartIndex].GuestFrameNumber) << EFI_PAGE_SHIFT;
RmpPageSize = Info->Entry[StartIndex].PageSize;
Ret = AsmPvalidate (RmpPageSize, Validate, Address);