## Summary
A SEGV on unknown address in `AP4_Processor::ProcessFragments` in Source/C++/Core/Ap4Processor.cpp:192. The address points to the zero page.

## Details

```
=================================================================
==27083==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x55e4af1ab58f bp 0x7ffc23973200 sp 0x7ffc23972d50 T0)
==27083==The signal is caused by a READ memory access.
==27083==Hint: address points to the zero page.
    #0 0x55e4af1ab58e in AP4_Processor::ProcessFragments(AP4_MoovAtom*, AP4_List<AP4_AtomLocator>&, AP4_ContainerAtom*, AP4_SidxAtom*, unsigned long long, AP4_ByteStream&, AP4_ByteStream&) Bento4/Source/C++/Core/Ap4Processor.cpp:285
    #1 0x55e4af1b30c6 in AP4_Processor::Process(AP4_ByteStream&, AP4_ByteStream&, AP4_ByteStream*, AP4_Processor::ProgressListener*, AP4_AtomFactory&) Bento4/Source/C++/Core/Ap4Processor.cpp:721
    #2 0x55e4af0496c9 in main Bento4/Source/C++/Apps/Mp4Decrypt/Mp4Decrypt.cpp:258
    #3 0x7fbf8aba6c86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21c86)
    #4 0x55e4af04d249 in _start (Bento4/mp4decrypt+0x36249)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV Bento4/Source/C++/Core/Ap4Processor.cpp:285 in AP4_Processor::ProcessFragments(AP4_MoovAtom*, AP4_List<AP4_AtomLocator>&, AP4_ContainerAtom*, AP4_SidxAtom*, unsigned long long, AP4_ByteStream&, AP4_ByteStream&)
==27083==ABORTING

```

## PoC

[mp4decrypt_poc.zip](https://github.com/axiomatic-systems/Bento4/files/9750526/mp4decrypt_poc.zip)

## Verification Step

```bash
git clone https://github.com/axiomatic-systems/Bento4
cd Bento4/
mkdir check_build && cd check_build
cmake ../ -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_C_FLAGS="-fsanitize=address" -DCMAKE_CXX_FLAGS="-fsanitize=address" -DCMAKE_BUILD_TYPE=Release
make -j

./mp4decrypt poc /dev/null
```

## Environment

- Ubuntu 18.04
- clang 10.01

## Version

Bento4 master branch [4df7274e](https://github.com/axiomatic-systems/Bento4/commit/4df7274e5e57e6219ca1e5dbdcb99ad1f7abb743) commit and version 1.6.0-639

SEGV on unknown address in mp4decrypt
This is a GitHub Issue
repo:Bento4
owner:axiomatic-systems
Title : SEGV on unknown address in mp4decrypt
Issue date:

--- start body ---
## Summary
A SEGV on unknown address in `AP4_Processor::ProcessFragments` in Source/C++/Core/Ap4Processor.cpp:192. The address points to the zero page.

## Details

```
=================================================================
==27083==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x55e4af1ab58f bp 0x7ffc23973200 sp 0x7ffc23972d50 T0)
==27083==The signal is caused by a READ memory access.
==27083==Hint: address points to the zero page.
    #0 0x55e4af1ab58e in AP4_Processor::ProcessFragments(AP4_MoovAtom*, AP4_List<AP4_AtomLocator>&, AP4_ContainerAtom*, AP4_SidxAtom*, unsigned long long, AP4_ByteStream&, AP4_ByteStream&) Bento4/Source/C++/Core/Ap4Processor.cpp:285
    #1 0x55e4af1b30c6 in AP4_Processor::Process(AP4_ByteStream&, AP4_ByteStream&, AP4_ByteStream*, AP4_Processor::ProgressListener*, AP4_AtomFactory&) Bento4/Source/C++/Core/Ap4Processor.cpp:721
    #2 0x55e4af0496c9 in main Bento4/Source/C++/Apps/Mp4Decrypt/Mp4Decrypt.cpp:258
    #3 0x7fbf8aba6c86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21c86)
    #4 0x55e4af04d249 in _start (Bento4/mp4decrypt+0x36249)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV Bento4/Source/C++/Core/Ap4Processor.cpp:285 in AP4_Processor::ProcessFragments(AP4_MoovAtom*, AP4_List<AP4_AtomLocator>&, AP4_ContainerAtom*, AP4_SidxAtom*, unsigned long long, AP4_ByteStream&, AP4_ByteStream&)
==27083==ABORTING

```

## PoC

[mp4decrypt_poc.zip](https://github.com/axiomatic-systems/Bento4/files/9750526/mp4decrypt_poc.zip)

## Verification Step

```bash
git clone https://github.com/axiomatic-systems/Bento4
cd Bento4/
mkdir check_build && cd check_build
cmake ../ -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_C_FLAGS="-fsanitize=address" -DCMAKE_CXX_FLAGS="-fsanitize=address" -DCMAKE_BUILD_TYPE=Release
make -j

./mp4decrypt poc /dev/null
```

## Environment

- Ubuntu 18.04
- clang 10.01

## Version

Bento4 master branch [4df7274e](https://github.com/axiomatic-systems/Bento4/commit/4df7274e5e57e6219ca1e5dbdcb99ad1f7abb743) commit and version 1.6.0-639

--- end body ---
