An unhandled memory allocation failure in Core/Ap4Atom.cpp of Bento 1.5.1-628 causes a NULL pointer dereference, leading to a denial of service (DOS).
There is a null pointer dereference bug running mp42aac.
It is similar to #413.

Distributor ID:	Ubuntu
Description:	Ubuntu 16.04.6 LTS
Release:	16.04
Codename:	xenial
gcc: 5.4.0

To reproduce the bug,
compile the project with flag
DCMAKE_C_FLAGS=-g -m32 -fsanitize=address,undefined

then run:
./mp42aac input /dev/null

The reason for this problem is due to the mishandled memory allocation:
![image](https://user-images.githubusercontent.com/7632714/62785850-04649d00-baf4-11e9-8335-b8f42ab92b45.png)

Here is the trace reported by ASAN:
/mnt/data/playground/mp42-a/Source/C++/Core/Ap4DataBuffer.cpp:175:41: runtime error: null pointer passed as argument 1, which is declared to never be null
/usr/include/i386-linux-gnu/bits/string3.h:53:71: runtime error: null pointer passed as argument 1, which is declared to never be null
==147453==WARNING: AddressSanitizer failed to allocate 0xfffffff8 bytes
==147453==AddressSanitizer's allocator is terminating the process instead of returning 0
==147453==If you don't like this behavior set allocator_may_return_null=1
==147453==AddressSanitizer CHECK failed: ../../../../../src/libsanitizer/sanitizer_common/sanitizer_allocator.cc:147 "((0)) != (0)" (0x0, 0x0)
    #0 0xf72aa797  (/usr/lib32/libasan.so.2+0x9f797)
    #1 0xf72afa69 in __sanitizer::CheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) (/usr/lib32/libasan.so.2+0xa4a69)
    #2 0xf722107b  (/usr/lib32/libasan.so.2+0x1607b)
    #3 0xf72ade80  (/usr/lib32/libasan.so.2+0xa2e80)
    #4 0xf7226229  (/usr/lib32/libasan.so.2+0x1b229)
    #5 0xf72a2e16 in operator new[](unsigned int) (/usr/lib32/libasan.so.2+0x97e16)
    #6 0x877ebaf in AP4_DataBuffer::AP4_DataBuffer(unsigned int) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4DataBuffer.cpp:55
    #7 0x889fddb in AP4_HvccAtom::Create(unsigned int, AP4_ByteStream&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4HvccAtom.cpp:86
    #8 0x82dc364 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4AtomFactory.cpp:488
    #9 0x82fa1f7 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4AtomFactory.cpp:225
    #10 0x82fa1f7 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, AP4_Atom*&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4AtomFactory.cpp:151
    #11 0x809a044 in AP4_File::ParseStream(AP4_ByteStream&, AP4_AtomFactory&, bool) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4File.cpp:104
    #12 0x809a044 in AP4_File::AP4_File(AP4_ByteStream&, bool) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4File.cpp:78
    #13 0x8082ce7 in main /mnt/data/playground/mp42-a/Source/C++/Apps/Mp42Aac/Mp42Aac.cpp:250
    #14 0xf6a2b636 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x18636)
    #15 0x808df1b  (/mnt/data/playground/mp42-patch/Build/mp42aac+0x808df1b)

This is the POC input:
[poc_input7.zip](https://github.com/axiomatic-systems/Bento4/files/3486744/poc_input7.zip)



Null pointer dereference bug
This is a GitHub Issue
repo:Bento4
owner:axiomatic-systems
Title : Null pointer dereference bug
Issue date:

--- start body ---
There is a null pointer dereference bug running mp42aac.
It is similar to #413.

Distributor ID:	Ubuntu
Description:	Ubuntu 16.04.6 LTS
Release:	16.04
Codename:	xenial
gcc: 5.4.0

To reproduce the bug,
compile the project with flag
DCMAKE_C_FLAGS=-g -m32 -fsanitize=address,undefined

then run:
./mp42aac input /dev/null

The reason for this problem is due to the mishandled memory allocation:
![image](https://user-images.githubusercontent.com/7632714/62785850-04649d00-baf4-11e9-8335-b8f42ab92b45.png)

Here is the trace reported by ASAN:
/mnt/data/playground/mp42-a/Source/C++/Core/Ap4DataBuffer.cpp:175:41: runtime error: null pointer passed as argument 1, which is declared to never be null
/usr/include/i386-linux-gnu/bits/string3.h:53:71: runtime error: null pointer passed as argument 1, which is declared to never be null
==147453==WARNING: AddressSanitizer failed to allocate 0xfffffff8 bytes
==147453==AddressSanitizer's allocator is terminating the process instead of returning 0
==147453==If you don't like this behavior set allocator_may_return_null=1
==147453==AddressSanitizer CHECK failed: ../../../../../src/libsanitizer/sanitizer_common/sanitizer_allocator.cc:147 "((0)) != (0)" (0x0, 0x0)
    #0 0xf72aa797  (/usr/lib32/libasan.so.2+0x9f797)
    #1 0xf72afa69 in __sanitizer::CheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) (/usr/lib32/libasan.so.2+0xa4a69)
    #2 0xf722107b  (/usr/lib32/libasan.so.2+0x1607b)
    #3 0xf72ade80  (/usr/lib32/libasan.so.2+0xa2e80)
    #4 0xf7226229  (/usr/lib32/libasan.so.2+0x1b229)
    #5 0xf72a2e16 in operator new[](unsigned int) (/usr/lib32/libasan.so.2+0x97e16)
    #6 0x877ebaf in AP4_DataBuffer::AP4_DataBuffer(unsigned int) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4DataBuffer.cpp:55
    #7 0x889fddb in AP4_HvccAtom::Create(unsigned int, AP4_ByteStream&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4HvccAtom.cpp:86
    #8 0x82dc364 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4AtomFactory.cpp:488
    #9 0x82fa1f7 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4AtomFactory.cpp:225
    #10 0x82fa1f7 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, AP4_Atom*&) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4AtomFactory.cpp:151
    #11 0x809a044 in AP4_File::ParseStream(AP4_ByteStream&, AP4_AtomFactory&, bool) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4File.cpp:104
    #12 0x809a044 in AP4_File::AP4_File(AP4_ByteStream&, bool) /mnt/data/playground/mp42-a/Source/C++/Core/Ap4File.cpp:78
    #13 0x8082ce7 in main /mnt/data/playground/mp42-a/Source/C++/Apps/Mp42Aac/Mp42Aac.cpp:250
    #14 0xf6a2b636 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x18636)
    #15 0x808df1b  (/mnt/data/playground/mp42-patch/Build/mp42aac+0x808df1b)

This is the POC input:
[poc_input7.zip](https://github.com/axiomatic-systems/Bento4/files/3486744/poc_input7.zip)



--- end body ---
