Re: [PATCH v2] MdeModulePkg/CapsuleApp: Fix memory leak issue.

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: Chen, Chen A
> Sent: Tuesday, February 12, 2019 3:56 PM
> To: edk2-devel@lists.01.org
> Cc: Chen, Chen A; Wang, Jian J; Wu, Hao A; Zhang, Chao B; Gao, Liming
> Subject: [PATCH v2] MdeModulePkg/CapsuleApp: Fix memory leak issue.
> 
> This issue is caused by FileInfoBuffer variable. This is a pointer array
> and each elements also pointer to a memory buffer that is allocated and
> returned by AllocateCopyPool function.
> 
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao Wu <hao.a.wu@intel.com>
> Cc: Zhang Chao B <chao.b.zhang@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Chen A Chen <chen.a.chen@intel.com>
> ---
>  MdeModulePkg/Application/CapsuleApp/CapsuleDump.c | 83
> ++++++++++++++++-------
>  1 file changed, 58 insertions(+), 25 deletions(-)
> 
> diff --git a/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c
> b/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c
> index ba2583accb..732472bb9c 100644
> --- a/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c
> +++ b/MdeModulePkg/Application/CapsuleApp/CapsuleDump.c
> @@ -806,48 +806,69 @@ DumpCapsuleFromDisk (
>    Status = Fs->OpenVolume (Fs, &Root);
>    if (EFI_ERROR (Status)) {
>      Print (L"Cannot open volume. Status = %r\n", Status);
> -    return EFI_NOT_FOUND;
> +    goto Done;
>    }
> 
>    Status = Root->Open (Root, &DirHandle, EFI_CAPSULE_FILE_DIRECTORY,
> EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE , 0);
>    if (EFI_ERROR (Status)) {
>      Print (L"Cannot open %s. Status = %r\n", EFI_CAPSULE_FILE_DIRECTORY,
> Status);
> -    return EFI_NOT_FOUND;
> +    goto Done;
>    }
> 
>    //
>    // Get file count first
>    //
> -  for ( Status = FileHandleFindFirstFile (DirHandle, &FileInfo)
> -      ; !EFI_ERROR(Status) && !NoFile
> -      ; Status = FileHandleFindNextFile (DirHandle, FileInfo, &NoFile)
> -     ){
> -    if ((FileInfo->Attribute & (EFI_FILE_SYSTEM | EFI_FILE_ARCHIVE)) == 0) {
> -      continue;
> +  do {
> +    Status = FileHandleFindFirstFile (DirHandle, &FileInfo);
> +    if (EFI_ERROR (Status) || FileInfo == NULL) {
> +      Print (L"Get File Info Fail. Status = %r\n", Status);
> +      goto Done;
>      }
> -    FileCount++;
> -  }
> +
> +    if ((FileInfo->Attribute & (EFI_FILE_SYSTEM | EFI_FILE_ARCHIVE)) != 0) {
> +      FileCount++;
> +    }
> +
> +    Status = FileHandleFindNextFile (DirHandle, FileInfo, &NoFile);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"Get Next File Fail. Status = %r\n", Status);
> +      goto Done;
> +    }
> +  } while (!NoFile);
> 
>    if (FileCount == 0) {
>      Print (L"Error: No capsule file found!\n");
> -    return EFI_NOT_FOUND;
> +    Status = EFI_NOT_FOUND;
> +    goto Done;
>    }
> 
>    FileInfoBuffer = AllocatePool (sizeof(FileInfo) * FileCount);

For me, AllocateZeroPool() should be used here.

Please refer to the reason below.

> +  if (FileInfoBuffer == NULL) {
> +    Status = EFI_OUT_OF_RESOURCES;
> +    goto Done;
> +  }
>    NoFile = FALSE;
> 
>    //
>    // Get all file info
>    //
> -  for ( Status = FileHandleFindFirstFile (DirHandle, &FileInfo)
> -      ; !EFI_ERROR (Status) && !NoFile
> -      ; Status = FileHandleFindNextFile (DirHandle, FileInfo, &NoFile)
> -     ){
> -    if ((FileInfo->Attribute & (EFI_FILE_SYSTEM | EFI_FILE_ARCHIVE)) == 0) {
> -      continue;
> +  do {
> +    Status = FileHandleFindFirstFile (DirHandle, &FileInfo);
> +    if (EFI_ERROR (Status) || FileInfo == NULL) {
> +      Print (L"Get File Info Fail. Status = %r\n", Status);
> +      goto Done;
> +    }
> +
> +    if ((FileInfo->Attribute & (EFI_FILE_SYSTEM | EFI_FILE_ARCHIVE)) != 0) {
> +      FileInfoBuffer[Index++] = AllocateCopyPool ((UINTN)FileInfo->Size,
> FileInfo);

If the memory allocation somehow fails during the 'do-while' loop, the
elements within array 'FileInfoBuffer' will not all have valid pointer
values.

So I believe, an 'AllocateZeroPool' should be used above.

With this addressed,
Reviewed-by: Hao Wu <hao.a.wu@intel.com>

Best Regards,
Hao Wu

>      }
> -    FileInfoBuffer[Index++] = AllocateCopyPool ((UINTN)FileInfo->Size,
> FileInfo);
> -  }
> +
> +    Status = FileHandleFindNextFile (DirHandle, FileInfo, &NoFile);
> +    if (EFI_ERROR (Status)) {
> +      Print (L"Get Next File Fail. Status = %r\n", Status);
> +      goto Done;
> +    }
> +  } while (!NoFile);
> 
>    //
>    // Sort FileInfoBuffer by alphabet order
> @@ -866,7 +887,8 @@ DumpCapsuleFromDisk (
>    }
> 
>    if (!DumpCapsuleInfo) {
> -    return EFI_SUCCESS;
> +    Status = EFI_SUCCESS;
> +    goto Done;
>    }
> 
>    Print(L"The infomation of the capsules:\n");
> @@ -875,19 +897,20 @@ DumpCapsuleFromDisk (
>      FileHandle = NULL;
>      Status = DirHandle->Open (DirHandle, &FileHandle,
> FileInfoBuffer[Index]->FileName, EFI_FILE_MODE_READ, 0);
>      if (EFI_ERROR (Status)) {
> -      break;
> +      goto Done;
>      }
> 
>      Status = FileHandleGetSize (FileHandle, (UINT64 *) &FileSize);
>      if (EFI_ERROR (Status)) {
>        Print (L"Cannot read file %s. Status = %r\n", FileInfoBuffer[Index]-
> >FileName, Status);
>        FileHandleClose (FileHandle);
> -      return Status;
> +      goto Done;
>      }
> 
>      FileBuffer = AllocatePool (FileSize);
>      if (FileBuffer == NULL) {
> -      return RETURN_OUT_OF_RESOURCES;
> +      Status = EFI_OUT_OF_RESOURCES;
> +      goto Done;
>      }
> 
>      Status = FileHandleRead (FileHandle, &FileSize, FileBuffer);
> @@ -895,7 +918,7 @@ DumpCapsuleFromDisk (
>        Print (L"Cannot read file %s. Status = %r\n", FileInfoBuffer[Index]-
> >FileName, Status);
>        FreePool (FileBuffer);
>        FileHandleClose (FileHandle);
> -      return Status;
> +      goto Done;
>      }
> 
>      Print (L"**************************\n");
> @@ -906,7 +929,17 @@ DumpCapsuleFromDisk (
>      FreePool (FileBuffer);
>    }
> 
> -  return EFI_SUCCESS;
> +Done:
> +  if (FileInfoBuffer != NULL) {
> +    for (Index = 0; Index < FileCount; Index++) {
> +      if (FileInfoBuffer[Index] != NULL) {
> +        FreePool (FileInfoBuffer[Index]);
> +      }
> +    }
> +    FreePool (FileInfoBuffer);
> +  }
> +
> +  return Status;
>  }
> 
>  /**
> --
> 2.16.2.windows.1