From 19cbfaa4319edabf5feb4e9d867f042c2d5e72b6 Mon Sep 17 00:00:00 2001 From: Dimitrije Pavlov Date: Thu, 28 Jul 2022 16:30:42 -0500 Subject: OvmfPkg/QemuVideoDxe: Zero out PixelInformation in QueryMode Ensure that the PixelInformation field of the EFI_GRAPHICS_OUTPUT_MODE_INFORMATION structure is zeroed out in EFI_GRAPHICS_OUTPUT_PROTOCOL.QueryMode() and EFI_GRAPHICS_OUTPUT_PROTOCOL.SetMode() when PixelFormat is PixelBlueGreenRedReserved8BitPerColor. According to UEFI 2.9 Section 12.9, PixelInformation field of the EFI_GRAPHICS_OUTPUT_MODE_INFORMATION structure is valid only if PixelFormat is PixelBitMask. This means that firmware is not required to fill out the PixelInformation field for other PixelFormat types, which implies that the QemuVideoDxe implementation is technically correct. However, not zeroing out those fields will leak the contents of the memory returned by the memory allocator, so it is better to explicitly set them to zero. In addition, the SCT test suite relies on PixelInformation always having a consistent value, which causes failures. Signed-off-by: Dimitrije Pavlov Acked-by: Gerd Hoffmann --- OvmfPkg/QemuVideoDxe/Gop.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'OvmfPkg/QemuVideoDxe') diff --git a/OvmfPkg/QemuVideoDxe/Gop.c b/OvmfPkg/QemuVideoDxe/Gop.c index 0c4dea7fb6..7a9fe208c9 100644 --- a/OvmfPkg/QemuVideoDxe/Gop.c +++ b/OvmfPkg/QemuVideoDxe/Gop.c @@ -31,7 +31,14 @@ QemuVideoCompleteModeInfo ( Info->PixelInformation.ReservedMask = 0; } else if (ModeData->ColorDepth == 32) { DEBUG ((DEBUG_INFO, "PixelBlueGreenRedReserved8BitPerColor\n")); - Info->PixelFormat = PixelBlueGreenRedReserved8BitPerColor; + Info->PixelFormat = PixelBlueGreenRedReserved8BitPerColor; + Info->PixelInformation.RedMask = 0; + Info->PixelInformation.GreenMask = 0; + Info->PixelInformation.BlueMask = 0; + Info->PixelInformation.ReservedMask = 0; + } else { + DEBUG ((DEBUG_ERROR, "%a: Invalid ColorDepth %u", __FUNCTION__, ModeData->ColorDepth)); + ASSERT (FALSE); } Info->PixelsPerScanLine = Info->HorizontalResolution; -- cgit v1.2.3