Re: [PATCH EDK2 v1 1/1] ArmPlatformPkg/Drivers/NorFlashDxe:avoid index out of bound

["wenyi,xie" <xiewenyi2@huawei.com>]

On 2022/10/30 18:06, Ard Biesheuvel wrote:
> On Sat, 29 Oct 2022 at 11:29, Wenyi Xie <xiewenyi2@huawei.com> wrote:
>>
>> The size of array BlockMap is 1 in struct FirmwareVolumeHeader, but in
>> function InitializeFvAndVariableStoreHeaders, BlockMap[1] is been written.
> 
> The size of BlockMap[] is not 1. BlockMap is a flexible array declared
> in an old fashioned way, and because the type definition is covered by
> the spec, we can not change it. Given that this is established idiom,
> compilers don't tend to warn about this.
> 
>> The memory of BlockMap[1] is already allocated, so the code is OK. But
>> it is better to use a new point to assign this memory.
>>
>> Cc: Leif Lindholm <quic_llindhol@quicinc.com>
>> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
>> Signed-off-by: Wenyi Xie <xiewenyi2@huawei.com>
> 
> Thanks for the patch but this driver is going to be deleted soon so no point.
> 
> There is new version of this driver in OvmfPkg/ but given the above, I
> don't think there is anything that needs fixing here.

Thank you for your answering, I got your point and so it seems no necessary to change.

Best Regards
Wenyi
> 
>> ---
>>  ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashFvb.c | 10 ++++++++--
>>  1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashFvb.c b/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashFvb.c
>> index 0767581308d2..2130e2e76344 100644
>> --- a/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashFvb.c
>> +++ b/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashFvb.c
>> @@ -47,6 +47,7 @@ InitializeFvAndVariableStoreHeaders (
>>    VOID                        *Headers;
>>    UINTN                       HeadersLength;
>>    EFI_FIRMWARE_VOLUME_HEADER  *FirmwareVolumeHeader;
>> +  EFI_FV_BLOCK_MAP_ENTRY      *BlockMapEntry;
>>    VARIABLE_STORE_HEADER       *VariableStoreHeader;
>>    UINT32                      NvStorageFtwSpareSize;
>>    UINT32                      NvStorageFtwWorkingSize;
>> @@ -151,10 +152,15 @@ InitializeFvAndVariableStoreHeaders (
>>    FirmwareVolumeHeader->Revision              = EFI_FVH_REVISION;
>>    FirmwareVolumeHeader->BlockMap[0].NumBlocks = Instance->Media.LastBlock + 1;
>>    FirmwareVolumeHeader->BlockMap[0].Length    = Instance->Media.BlockSize;
>> -  FirmwareVolumeHeader->BlockMap[1].NumBlocks = 0;
>> -  FirmwareVolumeHeader->BlockMap[1].Length    = 0;
>>    FirmwareVolumeHeader->Checksum              = CalculateCheckSum16 ((UINT16 *)FirmwareVolumeHeader, FirmwareVolumeHeader->HeaderLength);
>>
>> +  //
>> +  // EFI_FV_BLOCK_MAP_ENTRY
>> +  //
>> +  BlockMapEntry            = (EFI_FV_BLOCK_MAP_ENTRY *)((UINTN)Headers + sizeof (EFI_FIRMWARE_VOLUME_HEADER));
>> +  BlockMapEntry->NumBlocks = 0;
>> +  BlockMapEntry->Length    = 0;
>> +
>>    //
>>    // VARIABLE_STORE_HEADER
>>    //
>> --
>> 2.20.1.windows.1
>>
> .
>