Some heap buffer overflow bugs exist in avcinfo

[burymyname]

Hello, developers of Bento4!
I also found some heap buffer overflow bugs in avcinfo by using our fuzzing tools with ASAN.
Here is details:

Bug1

=================================================================
==48171==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000000038 at pc 0x7f1ff86b4733 bp 0x7fff66ab01b0 sp 0x7fff66aaf958
READ of size 8 at 0x602000000038 thread T0
    #0 0x7f1ff86b4732  (/usr/lib/x86_64-linux-gnu/libasan.so.4+0x79732)
    #1 0x5638f29e7432 in AP4_BitStream::WriteBytes(unsigned char const*, unsigned int) Bento4/Source/C++/Codecs/Ap4BitStream.cpp:133
    #2 0x5638f29c0c69 in PrintSliceInfo Bento4/Source/C++/Apps/AvcInfo/AvcInfo.cpp:84
    #3 0x5638f29c0c69 in main Bento4/Source/C++/Apps/AvcInfo/AvcInfo.cpp:172
    #4 0x7f1ff7ccac86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21c86)
    #5 0x5638f29c1679 in _start (Bento4/avcinfo+0x5679)

0x602000000038 is located 0 bytes to the right of 8-byte region [0x602000000030,0x602000000038)
allocated by thread T0 here:
    #0 0x7f1ff871b608 in operator new[](unsigned long) (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xe0608)
    #1 0x5638f29ed326 in AP4_DataBuffer::ReallocateBuffer(unsigned int) Bento4/Source/C++/Core/Ap4DataBuffer.cpp:210
    #2 0x5638f29ed326 in AP4_DataBuffer::SetDataSize(unsigned int) Bento4/Source/C++/Core/Ap4DataBuffer.cpp:151

SUMMARY: AddressSanitizer: heap-buffer-overflow (/usr/lib/x86_64-linux-gnu/libasan.so.4+0x79732) 
Shadow bytes around the buggy address:
  0x0c047fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c047fff8000: fa fa fd fa fa fa 00[fa]fa fa fa fa fa fa fa fa
  0x0c047fff8010: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8050: 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
==48171==ABORTING

Poc

avcinfo_poc1.zip

Bug2

=================================================================
==48988==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000000011 at pc 0x561df275ee6e bp 0x7ffca5855570 sp 0x7ffca5855560
READ of size 1 at 0x602000000011 thread T0
    #0 0x561df275ee6d in main Bento4/Source/C++/Apps/AvcInfo/AvcInfo.cpp:166
    #1 0x7f9a9fbd8c86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21c86)
    #2 0x561df275f679 in _start (Bento4/avcinfo+0x5679)

0x602000000011 is located 0 bytes to the right of 1-byte region [0x602000000010,0x602000000011)
allocated by thread T0 here:
    #0 0x7f9aa0629608 in operator new[](unsigned long) (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xe0608)
    #1 0x561df278b326 in AP4_DataBuffer::ReallocateBuffer(unsigned int) Bento4/Source/C++/Core/Ap4DataBuffer.cpp:210
    #2 0x561df278b326 in AP4_DataBuffer::SetDataSize(unsigned int) Bento4/Source/C++/Core/Ap4DataBuffer.cpp:151

SUMMARY: AddressSanitizer: heap-buffer-overflow Bento4/Source/C++/Apps/AvcInfo/AvcInfo.cpp:166 in main
Shadow bytes around the buggy address:
  0x0c047fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c047fff8000: fa fa[01]fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8010: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8050: 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
==48988==ABORTING

PoC

avcinfo_poc2.zip

Verification Steps

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
./avcinfo poc

Environment

• Ubuntu 18.04
• clang 10.01
• Bento4 master branch 4df7274e commit and version 1.6.0-639

Thanks for your time!