HDF5 version 1.15.0 currently under development
================================================================================


INTRODUCTION
============

This document describes the differences between this release and the previous
HDF5 release. It contains information on the platforms tested and known
problems in this release. For more details check the HISTORY*.txt files in the
HDF5 source.

Note that documentation in the links below will be updated at the time of each
final release.

Links to HDF5 documentation can be found on The HDF5 web page:

     https://portal.hdfgroup.org/display/HDF5/HDF5

The official HDF5 releases can be obtained from:

     https://www.hdfgroup.org/downloads/hdf5/

Changes from Release to Release and New Features in the HDF5-1.13.x release series
can be found at:

     https://portal.hdfgroup.org/display/HDF5/Release+Specific+Information

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS
========

- New Features
- Support for new platforms and languages
- Bug Fixes since HDF5-1.13.3
- Platforms Tested
- Known Problems
- CMake vs. Autotools installations


New Features
============

    Configuration:
    -------------
    - Removal of MPE support

      The ability to build with MPE instrumentation has been removed along with
      the following configure options:

      Autotools:
          --with-mpe=

      CMake has never supported building with MPE support.

      (DER - 2022/11/08)

     - Removal of dmalloc support

      The ability to build with dmalloc support has been removed along with
      the following configure options:

      Autotools:
          --with-dmalloc=

      CMake:
          HDF5_ENABLE_USING_DMALLOC

      (DER - 2022/11/08)

    - Removal of memory allocation sanity checks configure options

      With the removal of the memory allocation sanity checks feature, the
      following configure options are no longer necessary and have been
      removed:

      Autotools:
          --enable-memory-alloc-sanity-check

      CMake:
          HDF5_MEMORY_ALLOC_SANITY_CHECK
          HDF5_ENABLE_MEMORY_STATS

      (DER - 2022/11/03)

    Library:
    --------
    - Overhauled the Virtual Object Layer (VOL)

      The virtual object layer (VOL) was added in HDF5 1.12.0 but the initial
      implementation required API-breaking changes to better support optional
      operations and pass-through VOL connectors. The original VOL API is
      now considered deprecated and VOL users and connector authors should
      target the 1.14 VOL API.

      The specific changes are too extensive to document in a release note, so
      VOL users and connector authors should consult the updated VOL connector
      author's guide and the 1.12-1.14 VOL migration guide.

      (DER - 2022/12/28)

    - H5VLquery_optional() signature change

      The last parameter of this API call has changed from a pointer to hbool_t
      to a pointer to uint64_t. Due to the changes in how optional operations
      are handled in the 1.14 VOL API, we cannot make the old API call work
      with the new scheme, so there is no API compatibility macro for it.

      (DER - 2022/12/28)

    - H5I_free_t callback signature change

      In order to support asynchronous operations and future IDs, the signature
      of the H5I_free_t callback has been modified to take a second 'request'
      parameter. Due to the nature of the internal library changes, no API
      compatibility macro is available for this change.

      (DER - 2022/12/28)

    - Fix for CVE-2019-8396

      Malformed HDF5 files may have truncated content which does not match
      the expected size. When H5O__pline_decode() attempts to decode these it
      may read past the end of the allocated space leading to heap overflows
      as bounds checking is incomplete.

      The fix ensures each element is within bounds before reading.

      (2022/11/09 - HDFFV-10712, CVE-2019-8396, GitHub #2209)

    - Removal of memory allocation sanity checks feature

      This feature added heap canaries and statistics tracking for internal
      library memory operations. Unfortunately, the heap canaries caused
      problems when library memory operations were mixed with standard C
      library memory operations (such as in the filter pipeline, where
      buffers may have to be reallocated). Since any platform with a C
      compiler also usually has much more sophisticated memory sanity
      checking tools than the HDF5 library provided (e.g., valgrind), we
      have decided to to remove the feature entirely.

      In addition to the configure changes described above, this also removes
      the following from the public API:
          H5get_alloc_stats()
          H5_alloc_stats_t

      (DER - 2022/11/03)

    Parallel Library:
    -----------------
    -


    Fortran Library:
    ----------------
    -


    C++ Library:
    ------------
    -


    Java Library:
    -------------
    -


    Tools:
    ------
    -


    High-Level APIs:
    ----------------
    -


    C Packet Table API:
    -------------------
    -


    Internal header file:
    ---------------------
    -


    Documentation:
    --------------
    - Ported the existing VOL Connector Author Guide document to doxygen.

      Added new dox file, VOLConnGuide.dox.

      (ADB - 2022/12/20)


Support for new platforms, languages and compilers
==================================================
    -
    
Bug Fixes since HDF5-1.13.3 release
===================================
    Library
    -------
    - Seg fault on file close

      h5debug fails at file close with core dump on a file that has an
      illegal file size in its cache image.  In H5F_dest(), the library
      performs all the closing operations for the file and keeps track of
      the error encountered when reading the file cache image.  
      At the end of the routine, it frees the file's file structure and 
      returns error.  Due to the error return, the file object is not removed 
      from the ID node table.  This eventually causes assertion failure in 
      H5VL__native_file_close() when the library finally exits and tries to 
      access that file object in the table for closing.

      The closing routine, H5F_dest(), will not free the file structure if
      there is error, keeping a valid file structure in the ID node table.
      It will be freed later in H5VL__native_file_close() when the
      library exits and terminates the file package.

      (VC - 2022/12/14, HDFFV-11052, CVE-2020-10812)

    - Fix CVE-2018-13867 / GHSA-j8jr-chrh-qfrf
 
      Validate location (offset) of the accumulated metadata when comparing.

      Initially, the accumulated metadata location is initialized to HADDR_UNDEF
      - the highest available address. Bogus input files may provide a location
      or size matching this value. Comparing this address against such bogus
      values may provide false positives. Thus make sure, the value has been
      initialized or fail the comparison early and let other parts of the
      code deal with the bogus address/size.
      Note: To avoid unnecessary checks, it is assumed that if the 'dirty'
      member in the same structure is true the location is valid.

      (EFE - 2022/10/10 GH-2230)
      
    - Fix CVE-2018-16438 / GHSA-9xmm-cpf8-rgmx

      Make sure info block for external links has at least 3 bytes.
    
      According to the specification, the information block for external links
      contains 1 byte of version/flag information and two 0 terminated strings
      for the object linked to and the full path.
      Although not very useful, the minimum string length for each (with
      terminating 0) would be one byte.
      Checking this helps to avoid SEGVs triggered by bogus files.

      (EFE - 2022/10/09 GH-2233)

    - CVE-2021-46244 / GHSA-vrxh-5gxg-rmhm

      Compound datatypes may not have members of size 0
 
      A member size of 0 may lead to an FPE later on as reported in
      CVE-2021-46244. To avoid this, check for this as soon as the
      member is decoded.

      (EFE - 2022/10/05 GEH-2242)


    - Fix CVE-2021-45830 / GHSA-5h2h-fjjr-x9m2

      Make H5O__fsinfo_decode() more resilient to out-of-bound reads.

      When decoding a file space info message in H5O__fsinfo_decode()  make
      sure each element to be decoded is still within the message. Malformed
      hdf5 files may have trunkated content which does not match the
      expected size. Checking this will prevent attempting to decode
      unrelated data and heap overflows. So far, only free space manager
      address data was checked before decoding.

      (EFE - 2022/10/05 GH-2228)

    - Fix CVE-2021-46242 / GHSA-x9pw-hh7v-wjpf

      When evicting driver info block, NULL the corresponding entry.

      Since H5C_expunge_entry() called (from H5AC_expunge_entry()) sets the  flag
      H5C__FLUSH_INVALIDATE_FLAG, the driver info block will be freed. NULLing
      the pointer in f->shared->drvinfo will prevent use-after-free  when it is
      used in other functions (like  H5F__dest()) - as other places will check
      whether the pointer is initialized before using its value.

      (EFE - 2022/09/29 GH-2254)

    - Fix CVE-2021-45833 / GHSA-x57p-jwp6-4v79

      Report error if dimensions of chunked storage in data layout < 2
    
      For Data Layout Messages version 1 & 2 the specification state
      that the value stored in the data field is 1 greater than the
      number of dimensions in the dataspace. For version 3 this is
      not explicitly stated but the implementation suggests it to be
      the case.
      Thus the set value needs to be at least 2. For dimensionality
      < 2 an out-of-bounds access occurs.
 
      (EFE - 2022/09/28 GH-2240)
      
    - Fix CVE-2018-14031 / GHSA-2xc7-724c-r36j

      Parent of enum datatype message must have the same size as the
      enum datatype message itself.
      Functions accessing the enumeration values use the size of the
      enumeration datatype to determine the size of each element and
      how much data to copy.
      Thus the size of the enumeration and its parent need to match.
      Check in H5O_dtype_decode_helper()  to avoid unpleasant surprises
      later.

      (EFE - 2022/09/28 GH-2236)

    - Fix CVE-2018-17439 / GHSA-vcxv-vp43-rch7

      H5IMget_image_info(): Make sure to not exceed local array size

      Malformed hdf5 files may provide more dimensions than the array dim[] in
      H5IMget_image_info() is able to hold. Check number of elements first by calling
      H5Sget_simple_extent_dims() with NULL for both 'dims' and 'maxdims' arguments.
      This will cause the function to return only the number of dimensions.
      The fix addresses a stack overflow on write.

      (EFE - 2022/09/27 HDFFV-10589, GH-2226)


    Java Library
    ------------
    -


    Configuration
    -------------
    - Remove Javadoc generation

      The use of doxygen now supersedes the requirement to build javadocs. We do not
      have the resources to continue to support two documentation methods and have
      chosen doxygen as our standard.

      (ADB - 2022/12/19)

    - Change the default for building the high-level tools

      The gif2hdf5 and hdf2gif high-level tools are deprecated and will be removed
      in a future release. The default build setting for them have been changed from enabled
      to disabled. A user can enable the build of these tools if needed.
          autotools:   --enable-hlgiftools
          cmake:       HDF5_BUILD_HL_GIF_TOOLS=ON

      (ADB - 2022/12/16)

    - Change the settings of the *pc files to use the correct format

      The pkg-config files generated by CMake uses incorrect syntax for the 'Requires'
      settings. Changing the set to use 'lib-name = version' instead 'lib-name-version'
      fixes the issue

      (ADB - 2022/12/06 HDFFV-11355)

    - Move MPI libraries link from PRIVATE to PUBLIC

      The install dependencies were not including the need for MPI libraries when
      an application or library was built with the C library. Also updated the
      CMake target link command to use the newer style MPI::MPI_C link variable.

      (ADB - 2022/10/27)


    Tools
    -----
    - Fix h5repack to only print output when verbose option is selected

      When timing option was added to h5repack, the check for verbose was
      incorrectly implemented.

      (ADB -  2022/12/02, GH #2270)


    Performance
    -------------
    -


    Fortran API
    -----------
    -

    High-Level Library
    ------------------
    -


    Fortran High-Level APIs
    -----------------------
    -


    Documentation
    -------------
    -


    F90 APIs
    --------
    -


    C++ APIs
    --------
    - 


    Testing
    -------
    -


Platforms Tested
===================

    Linux 5.16.14-200.fc35           GNU gcc (GCC) 11.2.1 20220127 (Red Hat 11.2.1-9)
    #1 SMP x86_64  GNU/Linux         GNU Fortran (GCC) 11.2.1 20220127 (Red Hat 11.2.1-9)
    Fedora35                         clang version 13.0.0 (Fedora 13.0.0-3.fc35)
                                     (cmake and autotools)

    Linux 5.11.0-34-generic          GNU gcc (GCC) 9.3.0-17ubuntu1
    #36-Ubuntu SMP x86_64 GNU/Linux  GNU Fortran (GCC) 9.3.0-17ubuntu1
    Ubuntu 20.04                     Ubuntu clang version 10.0.0-4
                                     (cmake and autotools)

    Linux 5.3.18-150300-cray_shasta_c cray-mpich/8.1.16
    #1 SMP x86_64 GNU/Linux              Cray clang 14.0.0
    (crusher)                            GCC 11.2.0
                                     (cmake)

    Linux 4.14.0-115.35.1.1chaos     openmpi 4.0.5
    #1 SMP aarch64 GNU/Linux             GCC 9.2.0 (ARM-build-5)
    (stria)                              GCC 7.2.0 (Spack GCC)
                                     (cmake)

    Linux 4.14.0-115.35.1.3chaos     spectrum-mpi/rolling-release
    #1 SMP ppc64le GNU/Linux             clang 12.0.1
    (vortex)                             GCC 8.3.1
                                         XL 16.1.1
                                     (cmake)

    Linux-4.14.0-115.21.2            spectrum-mpi/rolling-release
    #1 SMP ppc64le GNU/Linux             clang 12.0.1, 14.0.5
    (lassen)                             GCC 8.3.1
                                         XL 16.1.1.2, 2021,09.22, 2022.08.05
                                     (cmake)

    Linux-4.12.14-197.99-default     cray-mpich/7.7.14
    #1 SMP x86_64 GNU/Linux              cce 12.0.3
    (theta)                              GCC 11.2.0
                                         llvm 9.0
                                         Intel 19.1.2

    Linux 3.10.0-1160.36.2.el7.ppc64 gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
    #1 SMP ppc64be GNU/Linux         g++ (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
    Power8 (echidna)                 GNU Fortran (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)

    Linux 3.10.0-1160.24.1.el7       GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux          compilers:
    Centos7                              Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly/kituo/moohan)                 Version 4.9.3, Version 5.3.0, Version 6.3.0,
                                         Version 7.2.0, Version 8.3.0, Version 9.1.0
                                     Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                     compilers:
                                         Version 17.0.0.098 Build 20160721
                                     GNU C (gcc) and C++ (g++) 4.8.5 compilers
                                         with NAG Fortran Compiler Release 6.1(Tozai)
                                     Intel(R) C (icc) and C++ (icpc) 17.0.0.098 compilers
                                         with NAG Fortran Compiler Release 6.1(Tozai)
                                     MPICH 3.1.4 compiled with GCC 4.9.3
                                     MPICH 3.3 compiled with GCC 7.2.0
                                     OpenMPI 2.1.6 compiled with icc 18.0.1
                                     OpenMPI 3.1.3 and 4.0.0 compiled with GCC 7.2.0
                                     PGI C, Fortran, C++ for 64-bit target on
                                     x86_64;
                                         Version 19.10-0
                                     (autotools and cmake)

    Linux-3.10.0-1160.0.0.1chaos     openmpi-4.1.2
    #1 SMP x86_64 GNU/Linux              clang 6.0.0, 11.0.1
    (quartz)                             GCC 7.3.0, 8.1.0
                                         Intel 19.0.4, 2022.2, oneapi.2022.2

    Linux-3.10.0-1160.71.1.1chaos    openmpi/4.1
    #1 SMP x86_64 GNU/Linux              GCC 7.2.0
    (skybridge)                          Intel/19.1
                                     (cmake)

    Linux-3.10.0-1160.66.1.1chaos    openmpi/4.1
    #1 SMP x86_64 GNU/Linux              GCC 7.2.0
    (attaway)                            Intel/19.1
                                     (cmake)

    Linux-3.10.0-1160.59.1.1chaos    openmpi/4.1
    #1 SMP x86_64 GNU/Linux              Intel/19.1
    (chama)                          (cmake)

    macOS Apple M1 11.6              Apple clang version 12.0.5 (clang-1205.0.22.11)
    Darwin 20.6.0 arm64              gfortran GNU Fortran (Homebrew GCC 11.2.0) 11.1.0
    (macmini-m1)                     Intel icc/icpc/ifort version 2021.3.0 202106092021.3.0 20210609

    macOS Big Sur 11.3.1             Apple clang version 12.0.5 (clang-1205.0.22.9)
    Darwin 20.4.0 x86_64             gfortran GNU Fortran (Homebrew GCC 10.2.0_3) 10.2.0
    (bigsur-1)                       Intel icc/icpc/ifort version 2021.2.0 20210228

    macOS High Sierra 10.13.6        Apple LLVM version 10.0.0 (clang-1000.10.44.4)
    64-bit                           gfortran GNU Fortran (GCC) 6.3.0
    (bear)                           Intel icc/icpc/ifort version 19.0.4.233 20190416

    macOS Sierra 10.12.6             Apple LLVM version 9.0.0 (clang-900.39.2)
    64-bit                           gfortran GNU Fortran (GCC) 7.4.0
    (kite)                           Intel icc/icpc/ifort version 17.0.2

    Mac OS X El Capitan 10.11.6      Apple clang version 7.3.0 from Xcode 7.3
    64-bit                           gfortran GNU Fortran (GCC) 5.2.0
    (osx1011test)                    Intel icc/icpc/ifort version 16.0.2


    Linux 2.6.32-573.22.1.el6        GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux          compilers:
    Centos6                              Version 4.4.7 20120313
    (platypus)                           Version 4.9.3, 5.3.0, 6.2.0
                                     MPICH 3.1.4 compiled with GCC 4.9.3
                                     PGI C, Fortran, C++ for 64-bit target on
                                     x86_64;
                                         Version 19.10-0

    Windows 10 x64                  Visual Studio 2015 w/ Intel C/C++/Fortran 18 (cmake)
                                    Visual Studio 2017 w/ Intel C/C++/Fortran 19 (cmake)
                                    Visual Studio 2019 w/ clang 12.0.0
                                        with MSVC-like command-line (C/C++ only - cmake)
                                    Visual Studio 2019 w/ Intel C/C++/Fortran oneAPI 2022 (cmake)
                                    Visual Studio 2022 w/ clang 15.0.1
                                        with MSVC-like command-line (C/C++ only - cmake)
                                    Visual Studio 2022 w/ Intel C/C++/Fortran oneAPI 2022 (cmake)
                                    Visual Studio 2019 w/ MSMPI 10.1 (C only - cmake)


Known Problems
==============

       ************************************************************
       *                                  _                       *
       *                                 (_)                      *
       *        __      ____ _ _ __ _ __  _ _ __   __ _           *
       *        \ \ /\ / / _` | '__| '_ \| | '_ \ / _` |          *
       *         \ V  V / (_| | |  | | | | | | | | (_| |          *
       *          \_/\_/ \__,_|_|  |_| |_|_|_| |_|\__, |          *
       *                                           __/ |          *
       *                                          |___/           *
       *                                                          *
       *  Please refrain from running any program (including      *
       *  HDF5 tests) which uses the subfiling VFD on Perlmutter  *
       *  at the National Energy Research Scientific Computing    *
       *  Center, NERSC.                                          *
       *  Doing so may cause a system disruption due to subfiling *
       *  crashing Lustre. The sytem's Lustre bug is expected     *
       *  to be resolved by 2023.                                 *
       *                                                          *
       ************************************************************

    CMake files do not behave correctly with paths containing spaces.
    Do not use spaces in paths because the required escaping for handling spaces
    results in very complex and fragile build files.
    ADB - 2019/05/07

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    CPP ptable test fails on both VS2017 and VS2019 with Intel compiler, JIRA
    issue: HDFFV-10628.  This test will pass with VS2015 with Intel compiler.

    The subsetting option in ph5diff currently will fail and should be avoided.
    The subsetting option works correctly in serial h5diff.

    Several tests currently fail on certain platforms:
        MPI_TEST-t_bigio fails with spectrum-mpi on ppc64le platforms.

        MPI_TEST-t_subfiling_vfd and MPI_TEST_EXAMPLES-ph5_subfiling fail with
        cray-mpich on theta and with XL compilers on ppc64le platforms.

        MPI_TEST_testphdf5_tldsc fails with cray-mpich 7.7 on cori and theta.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


CMake vs. Autotools installations
=================================
While both build systems produce similar results, there are differences.
Each system produces the same set of folders on linux (only CMake works
on standard Windows); bin, include, lib and share. Autotools places the
COPYING and RELEASE.txt file in the root folder, CMake places them in
the share folder.

The bin folder contains the tools and the build scripts. Additionally, CMake
creates dynamic versions of the tools with the suffix "-shared". Autotools
installs one set of tools depending on the "--enable-shared" configuration
option.
  build scripts
  -------------
  Autotools: h5c++, h5cc, h5fc
  CMake: h5c++, h5cc, h5hlc++, h5hlcc

The include folder holds the header files and the fortran mod files. CMake
places the fortran mod files into separate shared and static subfolders,
while Autotools places one set of mod files into the include folder. Because
CMake produces a tools library, the header files for tools will appear in
the include folder.

The lib folder contains the library files, and CMake adds the pkgconfig
subfolder with the hdf5*.pc files used by the bin/build scripts created by
the CMake build. CMake separates the C interface code from the fortran code by
creating C-stub libraries for each Fortran library. In addition, only CMake
installs the tools library. The names of the szip libraries are different
between the build systems.

The share folder will have the most differences because CMake builds include
a number of CMake specific files for support of CMake's find_package and support
for the HDF5 Examples CMake project.

The issues with the gif tool are:
    HDFFV-10592 CVE-2018-17433
    HDFFV-10593 CVE-2018-17436
    HDFFV-11048 CVE-2020-10809
These CVE issues have not yet been addressed and are avoided by not building
the gif tool by default. Enable building the High-Level tools with these options:
    autotools:   --enable-hltools
    cmake:       HDF5_BUILD_HL_TOOLS=ON
