From 4f10654e04601fe67a750c9b5a4242efd4141569 Mon Sep 17 00:00:00 2001 From: Jian J Wang Date: Tue, 16 Jan 2018 10:45:56 +0800 Subject: [PATCH] UefiCpuPkg/CpuDxe: fix SetMemoryAttributes issue in 32-bit mode In 32-bit mode, the BIOS will not create page table for memory beyond 4GB and therefore it cannot handle the attributes change request for those memory. But current CpuDxe doesn't check this situation and still try to complete the request, which will cause attributes of incorrect memory address to be changed due to type cast from 64-bit to 32-bit. This patch fixes this issue by checking the end address of input memory block and returning EFI_UNSUPPORTED if it's out of range. Cc: Eric Dong Cc: Laszlo Ersek Cc: Ruiyu Ni Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang Reviewed-by: Ruiyu Ni --- UefiCpuPkg/CpuDxe/CpuPageTable.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/UefiCpuPkg/CpuDxe/CpuPageTable.c b/UefiCpuPkg/CpuDxe/CpuPageTable.c index a9c9bc9d5e..3ad55f65c5 100644 --- a/UefiCpuPkg/CpuDxe/CpuPageTable.c +++ b/UefiCpuPkg/CpuDxe/CpuPageTable.c @@ -699,6 +699,10 @@ ConvertMemoryPageAttributes ( DEBUG ((DEBUG_ERROR, "Non-PAE Paging!\n")); return EFI_UNSUPPORTED; } + if ((BaseAddress + Length) > BASE_4GB) { + DEBUG ((DEBUG_ERROR, "Beyond 4GB memory in 32-bit mode!\n")); + return EFI_UNSUPPORTED; + } break; case IMAGE_FILE_MACHINE_X64: ASSERT (CurrentPagingContext.ContextData.X64.PageTableBase != 0); -- 2.39.2