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MdeModulePkg/Gcd: Check memory allocation when initializing memory 

CoreInitializeMemoryServices was not checking for any existing memory
allocation created in the HOB producer phase. If there are memory
allocations outside of the region covered by the HOB List then Gcd could
select that region for memory which can result in the memory allocation
to not be handled and memory overwrites.

Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Jeff Brasen 2020-10-29 01:35:02 +08:00 committed by mergify[bot]
parent 8d57088335
commit 978b9d511f
1 changed files with 58 additions and 0 deletions
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58
MdeModulePkg/Core/Dxe/Gcd/Gcd.c
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@ -2097,6 +2097,60 @@ CalculateTotalMemoryBinSizeNeeded (
return TotalSize;
}
/**
Find the largest region in the specified region that is not covered by an existing memory allocation
@param BaseAddress On input start of the region to check.
On output start of the largest free region.
@param Length On input size of region to check.
On output size of the largest free region.
@param MemoryHob Hob pointer for the first memory allocation pointer to check
**/
VOID
FindLargestFreeRegion (
IN OUT EFI_PHYSICAL_ADDRESS *BaseAddress,
IN OUT UINT64 *Length,
IN EFI_HOB_MEMORY_ALLOCATION *MemoryHob
)
{
EFI_PHYSICAL_ADDRESS TopAddress;
EFI_PHYSICAL_ADDRESS AllocatedTop;
EFI_PHYSICAL_ADDRESS LowerBase;
UINT64 LowerSize;
EFI_PHYSICAL_ADDRESS UpperBase;
UINT64 UpperSize;
TopAddress = *BaseAddress + *Length;
while (MemoryHob != NULL) {
AllocatedTop = MemoryHob->AllocDescriptor.MemoryBaseAddress + MemoryHob->AllocDescriptor.MemoryLength;
if ((MemoryHob->AllocDescriptor.MemoryBaseAddress >= *BaseAddress) &&
(AllocatedTop <= TopAddress)) {
LowerBase = *BaseAddress;
LowerSize = MemoryHob->AllocDescriptor.MemoryBaseAddress - *BaseAddress;
UpperBase = AllocatedTop;
UpperSize = TopAddress - AllocatedTop;
if (LowerSize != 0) {
FindLargestFreeRegion (&LowerBase, &LowerSize, (EFI_HOB_MEMORY_ALLOCATION *) GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, GET_NEXT_HOB (MemoryHob)));
}
if (UpperSize != 0) {
FindLargestFreeRegion (&UpperBase, &UpperSize, (EFI_HOB_MEMORY_ALLOCATION *) GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, GET_NEXT_HOB (MemoryHob)));
}
if (UpperSize >= LowerSize) {
*Length = UpperSize;
*BaseAddress = UpperBase;
} else {
*Length = LowerSize;
*BaseAddress = LowerBase;
}
return;
}
MemoryHob = GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, GET_NEXT_HOB (MemoryHob));
}
}
/**
External function. Initializes memory services based on the memory
descriptor HOBs. This function is responsible for priming the memory
@ -2235,6 +2289,7 @@ CoreInitializeMemoryServices (
Attributes = PhitResourceHob->ResourceAttribute;
BaseAddress = PageAlignAddress (PhitHob->EfiMemoryTop);
Length = PageAlignLength (ResourceHob->PhysicalStart + ResourceHob->ResourceLength - BaseAddress);
FindLargestFreeRegion (&BaseAddress, &Length, (EFI_HOB_MEMORY_ALLOCATION *)GetFirstHob (EFI_HOB_TYPE_MEMORY_ALLOCATION));
if (Length < MinimalMemorySizeNeeded) {
//
// If that range is not large enough to intialize the DXE Core, then
@ -2242,6 +2297,7 @@ CoreInitializeMemoryServices (
//
BaseAddress = PageAlignAddress (PhitHob->EfiFreeMemoryBottom);
Length = PageAlignLength (PhitHob->EfiFreeMemoryTop - BaseAddress);
//This region is required to have no memory allocation inside it, skip check for entries in HOB List
if (Length < MinimalMemorySizeNeeded) {
//
// If that range is not large enough to intialize the DXE Core, then
@ -2249,6 +2305,7 @@ CoreInitializeMemoryServices (
//
BaseAddress = PageAlignAddress (ResourceHob->PhysicalStart);
Length = PageAlignLength ((UINT64)((UINTN)*HobStart - BaseAddress));
FindLargestFreeRegion (&BaseAddress, &Length, (EFI_HOB_MEMORY_ALLOCATION *)GetFirstHob (EFI_HOB_TYPE_MEMORY_ALLOCATION));
}
}
break;
@ -2312,6 +2369,7 @@ CoreInitializeMemoryServices (
//
TestedMemoryBaseAddress = PageAlignAddress (ResourceHob->PhysicalStart);
TestedMemoryLength = PageAlignLength (ResourceHob->PhysicalStart + ResourceHob->ResourceLength - TestedMemoryBaseAddress);
FindLargestFreeRegion (&TestedMemoryBaseAddress, &TestedMemoryLength, (EFI_HOB_MEMORY_ALLOCATION *)GetFirstHob (EFI_HOB_TYPE_MEMORY_ALLOCATION));
if (TestedMemoryLength < MinimalMemorySizeNeeded) {
continue;
}