From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mx.groups.io with SMTP id smtpd.web11.2075.1656442108360802303 for ; Tue, 28 Jun 2022 11:48:28 -0700 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: arm.com, ip: 217.140.110.172, mailfrom: dimitrije.pavlov@arm.com) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 30795152B; Tue, 28 Jun 2022 11:48:28 -0700 (PDT) Received: from R90X9F89.arm.com (R90X9F89.arm.com [10.118.111.158]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C68373F792; Tue, 28 Jun 2022 11:48:27 -0700 (PDT) From: "Dimitrije Pavlov" To: devel@edk2.groups.io Cc: Ard Biesheuvel , Jiewen Yao , Jordan Justen , Gerd Hoffmann , Jeff Booher-Kaeding , Samer El-Haj-Mahmoud , Sunny Wang , Jeremy Linton Subject: [PATCH v1 1/1] OvmfPkg/QemuVideoDxe: Zero out PixelInformation in QueryMode Date: Tue, 28 Jun 2022 13:48:16 -0500 Message-Id: <20220628184816.24493-1-Dimitrije.Pavlov@arm.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit 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. Cc: Ard Biesheuvel Cc: Jiewen Yao Cc: Jordan Justen Cc: Gerd Hoffmann Cc: Jeff Booher-Kaeding Cc: Samer El-Haj-Mahmoud Cc: Sunny Wang Cc: Jeremy Linton Signed-off-by: Dimitrije Pavlov --- OvmfPkg/QemuVideoDxe/Gop.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/OvmfPkg/QemuVideoDxe/Gop.c b/OvmfPkg/QemuVideoDxe/Gop.c index 0c4dea7fb6f2..7a9fe208c99c 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; -- 2.34.1