commit c8ecaaf5e3d3f9b81d73f329501d3fa39739bd41
author Ruiyu Ni <ruiyu.ni@intel.com> Tue Jul 26 21:07:19 2016 +0800
committer Ruiyu Ni <ruiyu.ni@intel.com> Wed Jul 27 10:27:16 2016 +0800
tree 062effae0303d093e3ee19f467d39027614384c2
parent 96fcfdbfb068670b849a850bbed28ecad913af80

PcAtChipsetPkg/PcRtc: Fix a NULL pointer deference issue

When a platform which doesn't support ACPI 1.0 (no XSDT) and FADT
is not produced at the first time when ACPI table is published,
GetCenturyRtcAddress() unconditionally deference Rsdp->RsdtAddress
but Rsdp->RsdtAddress is 0 in this case.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>

PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c

diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
index 40d2e49..2bb41e7 100644
--- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
+++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
@@ -1250,8 +1250,6 @@
 {

   EFI_STATUS                                    Status;

   EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *Rsdp;

-  EFI_ACPI_DESCRIPTION_HEADER                   *Rsdt;

-  EFI_ACPI_DESCRIPTION_HEADER                   *Xsdt;

   EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE     *Fadt;

 

   Status = EfiGetSystemConfigurationTable (&gEfiAcpiTableGuid, (VOID **) &Rsdp);

@@ -1259,27 +1257,32 @@
     Status = EfiGetSystemConfigurationTable (&gEfiAcpi10TableGuid, (VOID **) &Rsdp);

   }

 

-  if (EFI_ERROR (Status)) {

+  if (EFI_ERROR (Status) || (Rsdp == NULL)) {

     return 0;

   }

 

-  ASSERT (Rsdp != NULL);

+  Fadt = NULL;

 

   //

   // Find FADT in XSDT

   //

-  Fadt = NULL;

-  if (Rsdp->Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION) {

-    Xsdt = (EFI_ACPI_DESCRIPTION_HEADER *) (UINTN) Rsdp->XsdtAddress;

-    Fadt = ScanTableInSDT (Xsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE, sizeof (UINTN));

+  if (Rsdp->Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION && Rsdp->XsdtAddress != 0) {

+    Fadt = ScanTableInSDT (

+             (EFI_ACPI_DESCRIPTION_HEADER *) (UINTN) Rsdp->XsdtAddress,

+             EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE,

+             sizeof (UINTN)

+             );

   }

 

-  if (Fadt == NULL) {

-    //

-    // Find FADT in RSDT

-    //

-    Rsdt = (EFI_ACPI_DESCRIPTION_HEADER *) (UINTN) Rsdp->RsdtAddress;

-    Fadt = ScanTableInSDT (Rsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE, sizeof (UINT32));

+  //

+  // Find FADT in RSDT

+  //

+  if (Fadt == NULL && Rsdp->RsdtAddress != 0) {

+    Fadt = ScanTableInSDT (

+             (EFI_ACPI_DESCRIPTION_HEADER *) (UINTN) Rsdp->RsdtAddress,

+             EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE,

+             sizeof (UINT32)

+             );

   }

 

   if ((Fadt != NULL) &&