From 01bd1c98fa83ef4449798fcf206fbd40db97b2d6 Mon Sep 17 00:00:00 2001 From: Star Zeng Date: Mon, 15 Jan 2018 10:26:07 +0800 Subject: [PATCH] IntelSiliconPkg IntelVTdDxe: Fix potential NULL pointer dereference The implementation of MdeModulePkg\Universal\Acpi\AcpiTableDxe reserves first entry of RSDT/XSDT to FADT, the first entry value is 0 when FADT is not installed. So the RSDT/XSDT parsing code should check the entry value first before checking the table signature. Cc: Jiewen Yao Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Star Zeng Reviewed-by: Jiewen Yao --- IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c index b981bcdb3a..342830a01f 100644 --- a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c +++ b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c @@ -1,6 +1,6 @@ /** @file - Copyright (c) 2017, Intel Corporation. All rights reserved.
+ Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -889,7 +889,7 @@ ScanTableInRSDT ( EntryPtr = &Rsdt->Entry; for (Index = 0; Index < EntryCount; Index ++, EntryPtr ++) { Table = (EFI_ACPI_DESCRIPTION_HEADER*)((UINTN)(*EntryPtr)); - if (Table->Signature == Signature) { + if ((Table != NULL) && (Table->Signature == Signature)) { return Table; } } @@ -923,7 +923,7 @@ ScanTableInXSDT ( for (Index = 0; Index < EntryCount; Index ++) { CopyMem (&EntryPtr, (VOID *)(BasePtr + Index * sizeof(UINT64)), sizeof(UINT64)); Table = (EFI_ACPI_DESCRIPTION_HEADER*)((UINTN)(EntryPtr)); - if (Table->Signature == Signature) { + if ((Table != NULL) && (Table->Signature == Signature)) { return Table; } }