xt-sys/exectos
3
5
Fork 2
Code Issues 4 Pull Requests Actions Projects 1 Releases Wiki Activity

Fix MADT subtable traversal
All checks were successful
Builds / ExectOS (amd64, debug) (push) Successful in -59m23s
Details
Builds / ExectOS (amd64, release) (push) Successful in -59m25s
Details
Builds / ExectOS (i686, debug) (push) Successful in -59m25s
Details
Builds / ExectOS (i686, release) (push) Successful in -59m27s
Details

Browse Source
This commit is contained in:
Aiken Harris
2026-05-04 15:02:39 +02:00
parent 48ef4bcdca
commit b417f84492
1 changed files with 16 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
xtoskrnl/hl/acpi.cc
View File

@@ -394,6 +394,7 @@ XTSTATUS
HL::Acpi::InitializeAcpiSystemStructure(VOID) HL::Acpi::InitializeAcpiSystemStructure(VOID)
{ {
PHYSICAL_ADDRESS PhysicalAddress; PHYSICAL_ADDRESS PhysicalAddress;
PACPI_SUBTABLE_HEADER SubTable;
PFN_NUMBER PageCount; PFN_NUMBER PageCount;
ULONG_PTR MadtTable; ULONG_PTR MadtTable;
PACPI_MADT Madt; PACPI_MADT Madt;
@@ -413,11 +414,19 @@ HL::Acpi::InitializeAcpiSystemStructure(VOID)
CpuCount = 0; CpuCount = 0;
/* Traverse all MADT tables to get number of processors */ /* Traverse all MADT tables to get number of processors */
while(MadtTable <= ((ULONG_PTR)Madt + Madt->Header.Length)) while(MadtTable < ((ULONG_PTR)Madt + Madt->Header.Length))
{ {
SubTable = (PACPI_SUBTABLE_HEADER)MadtTable;
/* Prevent infinite loops if BIOS provides 0 length */
if(SubTable->Length == 0)
{
/* Broken ACPI table, abort traversal */
break;
}
/* Check if this is a local APIC subtable */ /* Check if this is a local APIC subtable */
if((((PACPI_SUBTABLE_HEADER)MadtTable)->Type == ACPI_MADT_TYPE_LOCAL_APIC) && if(SubTable->Type == ACPI_MADT_TYPE_LOCAL_APIC && SubTable->Length >= sizeof(ACPI_MADT_LOCAL_APIC))
(((PACPI_SUBTABLE_HEADER)MadtTable)->Length == sizeof(ACPI_MADT_LOCAL_APIC)))
{ {
/* Make sure, this CPU can be enabled */ /* Make sure, this CPU can be enabled */
if(((PACPI_MADT_LOCAL_APIC)MadtTable)->Flags & ACPI_MADT_PLAOC_ENABLED) if(((PACPI_MADT_LOCAL_APIC)MadtTable)->Flags & ACPI_MADT_PLAOC_ENABLED)
@@ -425,12 +434,8 @@ HL::Acpi::InitializeAcpiSystemStructure(VOID)
/* Increment number of CPUs */ /* Increment number of CPUs */
CpuCount++; CpuCount++;
} }
/* Go to the next MADT table */
MadtTable += ((PACPI_SUBTABLE_HEADER)MadtTable)->Length;
} }
else if((((PACPI_SUBTABLE_HEADER)MadtTable)->Type == ACPI_MADT_TYPE_LOCAL_X2APIC) && else if(SubTable->Type == ACPI_MADT_TYPE_LOCAL_X2APIC && SubTable->Length >= sizeof(ACPI_MADT_LOCAL_X2APIC))
(((PACPI_SUBTABLE_HEADER)MadtTable)->Length == sizeof(ACPI_MADT_LOCAL_X2APIC)))
{ {
/* Make sure, this CPU can be enabled */ /* Make sure, this CPU can be enabled */
if(((PACPI_MADT_LOCAL_X2APIC)MadtTable)->Flags & ACPI_MADT_PLAOC_ENABLED) if(((PACPI_MADT_LOCAL_X2APIC)MadtTable)->Flags & ACPI_MADT_PLAOC_ENABLED)
@@ -438,15 +443,10 @@ HL::Acpi::InitializeAcpiSystemStructure(VOID)
/* Increment number of CPUs */ /* Increment number of CPUs */
CpuCount++; CpuCount++;
} }
}
/* Go to the next MADT table */ /* Safely advance pointer using proper subtable length */
MadtTable += ((PACPI_SUBTABLE_HEADER)MadtTable)->Length; MadtTable += SubTable->Length;
}
else
{
/* Any other MADT table, try to go to the next one byte-by-byte */
MadtTable += 1;
}
} }
/* Zero the ACPI system information structure */ /* Zero the ACPI system information structure */