# vtkExodusIIReader: Potential Memory Bugs

**URL:** https://discourse.vtk.org/t/vtkexodusiireader-potential-memory-bugs/16382
**Category:** Development
**Tags:** bug, file-formats
**Created:** [April 20, 2026, 4:55am UTC](https://discourse.vtk.org/t/vtkexodusiireader-potential-memory-bugs/16382 "2026-04-20T04:55:26Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![Landon-Huking](https://discourse.vtk.org/user_avatar/discourse.vtk.org/landon-huking/32/10618_2.png) [@Landon-Huking](https://discourse.vtk.org/u/Landon-Huking)
#### Post date: [April 20, 2026, 4:55am UTC](https://discourse.vtk.org/t/vtkexodusiireader-potential-memory-bugs/16382/1 "2026-04-20T04:55:27Z")

</div>

# Intro

Hi! I have been fuzzing VTK file readers and have potentially fond some memory bugs in the `vtkExodusIIReader` module.

# Fuzzing Setup

All fuzzing was done with AFL++ using a from source build of VTK with AFL instrumentation. Fuzzing was done for 1 hour over 3 seperate campaigns. Saved crashing test cases were triaged with ASAN. The CMake config for VTK is the following.

## VTK Version

Branch: master  
Commit: [00f9418c](https://gitlab.kitware.com/vtk/vtk/-/commits/master?search=unwrap-generic-array-template)

```auto
cmake ../ \
  -GNinja \
  -DCMAKE_C_COMPILER=afl-clang-fast \
  -DCMAKE_CXX_COMPILER=afl-clang-fast++ \
  -DCMAKE_BUILD_TYPE=Release \
  -DBUILD_SHARED_LIBS=ON \
  -DVTK_BUILD_TESTING=OFF \
  -DVTK_BUILD_EXAMPLES=OFF \
  -DVTK_GROUP_ENABLE_Rendering=NO \
  -DVTK_GROUP_ENABLE_Views=NO \
  -DVTK_GROUP_ENABLE_Web=NO \
  -DVTK_GROUP_ENABLE_Qt=NO \
  -DVTK_MODULE_ENABLE_VTK_RenderingCore=YES \
  -DVTK_MODULE_ENABLE_VTK_FiltersHybrid=YES \
  -DVTK_MODULE_ENABLE_VTK_IOLegacy=YES \
  -DVTK_MODULE_ENABLE_VTK_IOImage=YES \
  -DVTK_MODULE_ENABLE_VTK_IOGeometry=YES \
  -DVTK_MODULE_ENABLE_VTK_ImagingCore=YES \
  -DVTK_MODULE_ENABLE_VTK_CommonCore=YES \
  -DVTK_MODULE_ENABLE_VTK_CommonDataModel=YES

```

# 1: Heap-Buffer Overflow

Found in `vtkAOSDataArrayTemplate<ValueTypeT>::GetTuple` function. AFL++ found several malformed exodus test cases which triggered invalid 8 byte reads beyond the allocated memory of the `data` array.

```auto
template <class ValueTypeT>
double* vtkAOSDataArrayTemplate<ValueTypeT>::GetTuple(vtkIdType tupleIdx)
{
  ValueTypeT* data = this->Buffer->GetBuffer() + tupleIdx * this->NumberOfComponents;
  double* tuple = this->LegacyTuple.data();
  // See note in SetTuple about std::copy vs for loops on MSVC.
  for (int i = 0; i < this->NumberOfComponents; ++i)
  {
    tuple[i] = static_cast<double>(data[i]);
  }
  return this->LegacyTuple.data();
}

```

## ASAN Output

```auto
=================================================================
==88262==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x532000016fe8 at pc 0xffffa37b4dd8 bp 0xffffea362360 sp 0xffffea362358
READ of size 8 at 0x532000016fe8 thread T0
    #0 0xffffa37b4dd4 in vtkAOSDataArrayTemplate<double>::GetTuple(long long) /work/final/vtk/Common/Core/vtkAOSDataArrayTemplate.txx:294:36
    #1 0xffffa99db8c8 in vtkExodusIIReaderPrivate::AssembleOutputPoints(long long, vtkExodusIIReaderPrivate::BlockSetInfoType*, vtkUnstructuredGrid*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:546:38
    #2 0xffffa9a0cff4 in vtkExodusIIReaderPrivate::RequestData(long long, vtkMultiBlockDataSet*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:4531:15
    #3 0xffffa9a18cc8 in vtkExodusIIReader::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:5547:19
    #4 0xffffa90eb5f4 in vtkExecutive::CallAlgorithm(vtkInformation*, int, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkExecutive.cxx:723:33
    #5 0xffffa90d9a80 in vtkDemandDrivenPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:447:22
    #6 0xffffa90cf350 in vtkCompositeDataPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkCompositeDataPipeline.cxx:151:32
    #7 0xffffa90d858c in vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:246:22
    #8 0xffffa9152d38 in vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx
    #9 0xffffa90d9444 in vtkDemandDrivenPipeline::UpdateData(int) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:404:16
    #10 0xffffa9153eb8 in vtkStreamingDemandDrivenPipeline::Update(int, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx:421:34
    #11 0xffffa90c58a4 in vtkAlgorithm::Update(int) /work/final/vtk/Common/ExecutionModel/vtkAlgorithm.cxx:1660:32
    #12 0xaaaada13a548 in main /work/final/fuzzing-vtk/exodusTestSimple.cpp:14:10
    #13 0xffffa20684c0 (/lib/aarch64-linux-gnu/libc.so.6+0x284c0) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #14 0xffffa2068594 in __libc_start_main (/lib/aarch64-linux-gnu/libc.so.6+0x28594) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #15 0xaaaada055e2c in _start (/work/final/Fuzzing-VTK/build/harness-asan+0x35e2c) (BuildId: 37da1d56ebb97cbdd7c9ab2560fd5cbcf420849d)

0x532000016fe8 is located 1560 bytes after 90576-byte region [0x532000000800,0x5320000169d0)
allocated by thread T0 here:
    #0 0xaaaada0f88f4 in malloc (/work/final/Fuzzing-VTK/build/harness-asan+0xd88f4) (BuildId: 37da1d56ebb97cbdd7c9ab2560fd5cbcf420849d)
    #1 0xffffa37b8980 in vtkBuffer<double>::Allocate(long long) /work/final/vtk/Common/Core/vtkBuffer.h:202:43
    #2 0xffffa38316b4 in vtkAOSDataArrayTemplate<double>::ReallocateTuples(long long) /work/final/vtk/Common/Core/vtkAOSDataArrayTemplate.txx:488:21
    #3 0xffffa38316b4 in vtkGenericDataArray<vtkAOSDataArrayTemplate<double>, double, 5>::ReallocateTuples(long long) /work/final/vtk/Common/Core/vtkGenericDataArray.h:358:42
    #4 0xffffa38316b4 in vtkGenericDataArray<vtkAOSDataArrayTemplate<double>, double, 5>::ReserveTuples(long long) /work/final/vtk/Common/Core/vtkGenericDataArray.txx:455:14
    #5 0xffffa6dbcf40 in vtkAbstractArray::ReserveValues(long long) /work/final/vtk/Common/Core/vtkAbstractArray.cxx:216:16
    #6 0xffffa6dbcf40 in vtkAbstractArray::SetNumberOfValues(long long) /work/final/vtk/Common/Core/vtkAbstractArray.cxx:222:14
    #7 0xffffa99e16b4 in vtkExodusIIReaderPrivate::GetCacheOrRead(vtkExodusIICacheKey) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:2547:10
    #8 0xffffa99db718 in vtkExodusIIReaderPrivate::AssembleOutputPoints(long long, vtkExodusIIReaderPrivate::BlockSetInfoType*, vtkUnstructuredGrid*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:533:11
    #9 0xffffa9a0cff4 in vtkExodusIIReaderPrivate::RequestData(long long, vtkMultiBlockDataSet*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:4531:15
    #10 0xffffa9a18cc8 in vtkExodusIIReader::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:5547:19
    #11 0xffffa90eb5f4 in vtkExecutive::CallAlgorithm(vtkInformation*, int, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkExecutive.cxx:723:33
    #12 0xffffa90d9a80 in vtkDemandDrivenPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:447:22
    #13 0xffffa90cf350 in vtkCompositeDataPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkCompositeDataPipeline.cxx:151:32
    #14 0xffffa90d858c in vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:246:22
    #15 0xffffa9152d38 in vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx
    #16 0xffffa90d9444 in vtkDemandDrivenPipeline::UpdateData(int) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:404:16
    #17 0xffffa9153eb8 in vtkStreamingDemandDrivenPipeline::Update(int, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx:421:34
    #18 0xffffa90c58a4 in vtkAlgorithm::Update(int) /work/final/vtk/Common/ExecutionModel/vtkAlgorithm.cxx:1660:32
    #19 0xaaaada13a548 in main /work/final/fuzzing-vtk/exodusTestSimple.cpp:14:10
    #20 0xffffa20684c0 (/lib/aarch64-linux-gnu/libc.so.6+0x284c0) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #21 0xffffa2068594 in __libc_start_main (/lib/aarch64-linux-gnu/libc.so.6+0x28594) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #22 0xaaaada055e2c in _start (/work/final/Fuzzing-VTK/build/harness-asan+0x35e2c) (BuildId: 37da1d56ebb97cbdd7c9ab2560fd5cbcf420849d)

SUMMARY: AddressSanitizer: heap-buffer-overflow /work/final/vtk/Common/Core/vtkAOSDataArrayTemplate.txx:294:36 in vtkAOSDataArrayTemplate<double>::GetTuple(long long)
Shadow bytes around the buggy address:
  0x532000016d00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000016d80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000016e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000016e80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000016f00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x532000016f80: fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]fa fa
  0x532000017000: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000017080: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000017100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000017180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x532000017200: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable: 00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone: fa
  Freed heap region: fd
  Stack left redzone: f1
  Stack mid redzone: f2
  Stack right redzone: f3
  Stack after return: f5
  Stack use after scope: f8
  Global redzone: f9
  Global init order: f6
  Poisoned by user: f7
  Container overflow: fc
  Array cookie: ac
  Intra object redzone: bb
  ASan internal: fe
  Left alloca redzone: ca
  Right alloca redzone: cb
==88262==ABORTING

```

# 2: Nullptr Dereference

Found in `tkExodusIIReaderPrivate::GetSortedObjectInfo` function. Again, AFL++ found several generated test cases that trigger a nullptr dereference.

```auto
vtkExodusIIReaderPrivate::ObjectInfoType* vtkExodusIIReaderPrivate::GetSortedObjectInfo(
  int otyp, int k)
{
  int i = this->GetObjectTypeIndexFromObjectType(otyp);
  if (i < 0)
  {
    vtkDebugMacro("Could not find collection of objects with type " << otyp << ".");
    return nullptr;
  }
  int N = this->GetNumberOfObjectsAtTypeIndex(i);
  if (k < 0 || k >= N)
  {
    const char* otname = i >= 0 ? objtype_names[i] : "object";
    static_cast<void>(otname); // not referenced warning
    vtkDebugMacro(
      "You requested " << otname << " " << k << " in a collection of only " << N << " objects.");
    return nullptr;
  }
  return this->GetObjectInfo(i, this->SortedObjectIndices[otyp][k]);
}

```

## ASAN Output

```auto
e[0me[31m2026-04-18 22:07:50.524 ( 0.015s) [FFFFA1E1C020] vtkExodusIIReader.cxx:4276 ERR| vtkExodusIIReaderPrivate (0x51900002df80): Could not read set parameters.e[0m

AddressSanitizer:DEADLYSIGNAL
=================================================================
==88570==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0xffff84b6b598 bp 0xffffecf38bc0 sp 0xffffecf38980 T0)
==88570==The signal is caused by a READ memory access.
==88570==Hint: address points to the zero page.
    #0 0xffff84b6b598 in vtkExodusIIReaderPrivate::GetSortedObjectInfo(int, int) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:2954:33
    #1 0xffff84b6b598 in vtkExodusIIReaderPrivate::GetObjectName(int, int) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:4845:34
    #2 0xffff84b6b598 in vtkExodusIIReaderPrivate::RequestData(long long, vtkMultiBlockDataSet*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:4497:39
    #3 0xffff84b78cc8 in vtkExodusIIReader::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:5547:19
    #4 0xffff840eb5f4 in vtkExecutive::CallAlgorithm(vtkInformation*, int, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkExecutive.cxx:723:33
    #5 0xffff840d9a80 in vtkDemandDrivenPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:447:22
    #6 0xffff840cf350 in vtkCompositeDataPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkCompositeDataPipeline.cxx:151:32
    #7 0xffff840d858c in vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:246:22
    #8 0xffff84152d38 in vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx
    #9 0xffff840d9444 in vtkDemandDrivenPipeline::UpdateData(int) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:404:16
    #10 0xffff84153eb8 in vtkStreamingDemandDrivenPipeline::Update(int, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx:421:34
    #11 0xffff840c58a4 in vtkAlgorithm::Update(int) /work/final/vtk/Common/ExecutionModel/vtkAlgorithm.cxx:1660:32
    #12 0xaaaabefea548 in main /work/final/fuzzing-vtk/exodusTestSimple.cpp:14:10
    #13 0xffff7d2284c0 (/lib/aarch64-linux-gnu/libc.so.6+0x284c0) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #14 0xffff7d228594 in __libc_start_main (/lib/aarch64-linux-gnu/libc.so.6+0x28594) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #15 0xaaaabef05e2c in _start (/work/final/Fuzzing-VTK/build/harness-asan+0x35e2c) (BuildId: 37da1d56ebb97cbdd7c9ab2560fd5cbcf420849d)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:2954:33 in vtkExodusIIReaderPrivate::GetSortedObjectInfo(int, int)
==88570==ABORTING

```

# 3: Invalid Pointer Dereference

Found in `vtkAOSDataArrayTemplate<long long>::GetPointer(long long)`. Could be caused by trying to access `Buffer` despite invalid contents or state.

```auto
template <class ValueTypeT>
typename vtkAOSDataArrayTemplate<ValueTypeT>::ValueType*
vtkAOSDataArrayTemplate<ValueTypeT>::GetPointer(vtkIdType valueIdx)
{
  return this->Buffer->GetBuffer() + valueIdx;
}

```

## ASAN Output

```auto
e[0me[31m2026-04-18 22:09:10.514 ( 0.013s) [FFFF97CE4020] vtkExodusIIReader.cxx:4060 ERR| vtkExodusIIReaderPrivate (0x51900002df80): Could not read object ids for i=6 and otyp=3.e[0m
e[0me[31m2026-04-18 22:09:10.517 ( 0.016s) [FFFF97CE4020] vtkExodusIIReader.cxx:2215 ERR| vtkExodusIIReaderPrivate (0x51900002df80): Unable to read Element block -1509949431 (index 0) nodal connectivity.e[0m
AddressSanitizer:DEADLYSIGNAL
=================================================================
==12206==ERROR: AddressSanitizer: SEGV on unknown address 0x0000000001a8 (pc 0xffff92b93950 bp 0xffffc1d70a50 sp 0xffffc1d70a50 T0)
==12206==The signal is caused by a READ memory access.
==12206==Hint: address points to the zero page.
    #0 0xffff92b93950 in vtkAOSDataArrayTemplate<long long>::GetPointer(long long) /work/final/vtk/Common/Core/vtkAOSDataArrayTemplate.txx:454:16
    #1 0xffff97bf0220 in vtkExodusIIReaderPrivate::GetCacheOrRead(vtkExodusIICacheKey) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:2221:22
    #2 0xffff97be9ea0 in vtkExodusIIReaderPrivate::InsertBlockCells(int, int, int, int, vtkExodusIIReaderPrivate::BlockInfoType*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:1209:11
    #3 0xffff97be970c in vtkExodusIIReaderPrivate::AssembleOutputConnectivity(long long, int, int, int, vtkExodusIIReaderPrivate::BlockSetInfoType*, vtkUnstructuredGrid*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:487:11
    #4 0xffff97c1cfe0 in vtkExodusIIReaderPrivate::RequestData(long long, vtkMultiBlockDataSet*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:4527:15
    #5 0xffff97c28cc8 in vtkExodusIIReader::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/IO/Exodus/vtkExodusIIReader.cxx:5547:19
    #6 0xffff972eb5f4 in vtkExecutive::CallAlgorithm(vtkInformation*, int, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkExecutive.cxx:723:33
    #7 0xffff972d9a80 in vtkDemandDrivenPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:447:22
    #8 0xffff972cf350 in vtkCompositeDataPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkCompositeDataPipeline.cxx:151:32
    #9 0xffff972d858c in vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:246:22
    #10 0xffff97352d38 in vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx
    #11 0xffff972d9444 in vtkDemandDrivenPipeline::UpdateData(int) /work/final/vtk/Common/ExecutionModel/vtkDemandDrivenPipeline.cxx:404:16
    #12 0xffff97353eb8 in vtkStreamingDemandDrivenPipeline::Update(int, vtkInformationVector*) /work/final/vtk/Common/ExecutionModel/vtkStreamingDemandDrivenPipeline.cxx:421:34
    #13 0xffff972c58a4 in vtkAlgorithm::Update(int) /work/final/vtk/Common/ExecutionModel/vtkAlgorithm.cxx:1660:32
    #14 0xaaaac9d8a548 in main /work/final/fuzzing-vtk/exodusTestSimple.cpp:14:10
    #15 0xffff902684c0 (/lib/aarch64-linux-gnu/libc.so.6+0x284c0) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #16 0xffff90268594 in __libc_start_main (/lib/aarch64-linux-gnu/libc.so.6+0x28594) (BuildId: d6c205bda1b6e91815f8fef45bdf56bc2239c37e)
    #17 0xaaaac9ca5e2c in _start (/work/final/Fuzzing-VTK/build/harness-asan+0x35e2c) (BuildId: 37da1d56ebb97cbdd7c9ab2560fd5cbcf420849d)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /work/final/vtk/Common/Core/vtkAOSDataArrayTemplate.txx:454:16 in vtkAOSDataArrayTemplate<long long>::GetPointer(long long)
==12206==ABORTING

```

# Example Crashing Test Cases

Attached is a set of representing AFL++ mutated exodus files that can reproduce the results. Included is also the starting seed file which should not crash.

EDIT: New users aren’t allowed to add attachements so fell free to reach out for the example crashing files.

# AI Use Disclosure

LLMs were used to help with understanding module dependencies, library modules, and general API use. No AI was used in fuzzing configuration or running experiments.

---

<div class="post-metadata">

### Author: ![amaclean](https://discourse.vtk.org/user_avatar/discourse.vtk.org/amaclean/32/224_2.png) [@amaclean](https://discourse.vtk.org/u/amaclean)
#### Post date: [April 21, 2026, 7:05am UTC](https://discourse.vtk.org/t/vtkexodusiireader-potential-memory-bugs/16382/2 "2026-04-21T07:05:09Z")

</div>

I wonder if similar things are happening here: [https://gitlab.kitware.com/vtk/vtk/-/work\_items/20012](https://gitlab.kitware.com/vtk/vtk/-/work_items/20012)

Also: [https://gitlab.kitware.com/vtk/vtk-examples/-/merge\_requests/460](https://gitlab.kitware.com/vtk/vtk-examples/-/merge_requests/460)

---

<div class="post-metadata">

### Author: ![Landon-Huking](https://discourse.vtk.org/user_avatar/discourse.vtk.org/landon-huking/32/10618_2.png) [@Landon-Huking](https://discourse.vtk.org/u/Landon-Huking)
#### Post date: [April 21, 2026, 3:39pm UTC](https://discourse.vtk.org/t/vtkexodusiireader-potential-memory-bugs/16382/3 "2026-04-21T15:39:03Z")

</div>

Here is the example crashing test cases.  
[examples.zip](https://discourse.vtk.org/uploads/short-url/hMK9Bunq2HoQC9cojgEZV1EyXgN.zip) (183.8 KB)