Memory Leak in MP4BytesProperty

[AceSrc]

I found a memory leak error in mp4property.cpp:533; it seems that the value of the member variable count is inconsistent.

Environment

OS: Ubuntu 18.04.6 LTS
Compiler: gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)

Compilation

autoreconf -i
CC=gcc CXX=g++ CFLAGS='-fsanitize=address -g' CXXFLAGS='-fsanitize=address -g' ./configure
make -j32

Command Line

./mp4info poc_BytesProperty.mp4

POC

poc_BytesProperty.mp4.zip

Report

/home/poc/mp4v2/.libs/mp4info version 2.1.2
/home/poc/poc_BytesProperty.mp4:
ReadAtom: "/home/poc/poc_BytesProperty.mp4": invalid atom size, extends outside parent atom - skipping to end of "" "moov" 11495 vs 896
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Mandatory descriptor 0x0e missing
Read: "/home/poc/poc_BytesProperty.mp4": Descriptor 0x10 has more than one instance
ReadProperties: atom 'iods' is too small; overrun at property:  (src/mp4atom.cpp,392)
/home/poc/mp4v2/.libs/mp4info: can't open /home/poc/poc_BytesProperty.mp4

=================================================================
==13934==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 3 byte(s) in 1 object(s) allocated from:
    #0 0x7f338562db40 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb40)
    #1 0x7f3384fdf4ac in mp4v2::impl::MP4Malloc(unsigned long) src/mp4util.h:63
    #2 0x7f3384ff0d89 in mp4v2::impl::MP4Calloc(unsigned long) src/mp4util.h:72
    #3 0x7f338507432f in mp4v2::impl::MP4BytesProperty::MP4BytesProperty(mp4v2::impl::MP4Atom&, char const*, unsigned int, unsigned int) src/mp4property.cpp:533
    #4 0x7f33850945b7 in mp4v2::impl::MP4CreatorDescriptor::MP4CreatorDescriptor(mp4v2::impl::MP4Atom&, unsigned char) src/ocidescriptors.cpp:202
    #5 0x7f3385095061 in mp4v2::impl::CreateOCIDescriptor(mp4v2::impl::MP4Atom&, unsigned char) src/ocidescriptors.cpp:296
    #6 0x7f338500bd3a in mp4v2::impl::MP4DescriptorProperty::CreateDescriptor(mp4v2::impl::MP4Atom&, unsigned char) src/descriptors.cpp:602
    #7 0x7f33850790f5 in mp4v2::impl::MP4DescriptorProperty::AddDescriptor(unsigned char) src/mp4property.cpp:904
    #8 0x7f3385079fa8 in mp4v2::impl::MP4DescriptorProperty::Read(mp4v2::impl::MP4File&, unsigned int) src/mp4property.cpp:1019
    #9 0x7f338503bfbf in mp4v2::impl::MP4Descriptor::ReadProperties(mp4v2::impl::MP4File&, unsigned int, unsigned int) src/mp4descriptor.cpp:122
    #10 0x7f338503b77e in mp4v2::impl::MP4Descriptor::Read(mp4v2::impl::MP4File&) src/mp4descriptor.cpp:80
    #11 0x7f338507a01a in mp4v2::impl::MP4DescriptorProperty::Read(mp4v2::impl::MP4File&, unsigned int) src/mp4property.cpp:1021
    #12 0x7f338502fcc1 in mp4v2::impl::MP4Atom::ReadProperties(unsigned int, unsigned int) src/mp4atom.cpp:383
    #13 0x7f338502f056 in mp4v2::impl::MP4Atom::Read() src/mp4atom.cpp:237
    #14 0x7f338502eab9 in mp4v2::impl::MP4Atom::ReadAtom(mp4v2::impl::MP4File&, mp4v2::impl::MP4Atom*) src/mp4atom.cpp:202
    #15 0x7f3385030770 in mp4v2::impl::MP4Atom::ReadChildAtoms() src/mp4atom.cpp:435
    #16 0x7f338502f07b in mp4v2::impl::MP4Atom::Read() src/mp4atom.cpp:241
    #17 0x7f338502eab9 in mp4v2::impl::MP4Atom::ReadAtom(mp4v2::impl::MP4File&, mp4v2::impl::MP4Atom*) src/mp4atom.cpp:202
    #18 0x7f3385030770 in mp4v2::impl::MP4Atom::ReadChildAtoms() src/mp4atom.cpp:435
    #19 0x7f338502f07b in mp4v2::impl::MP4Atom::Read() src/mp4atom.cpp:241
    #20 0x7f338504098f in mp4v2::impl::MP4File::ReadFromFile() src/mp4file.cpp:457
    #21 0x7f338503d417 in mp4v2::impl::MP4File::Read(char const*, MP4FileProvider_s const*, MP4IOCallbacks_s const*, void*) src/mp4file.cpp:101
    #22 0x7f33850193e6 in MP4ReadProvider src/mp4.cpp:105
    #23 0x7f3385019389 in MP4Read src/mp4.cpp:92
    #24 0x7f338506f3f8 in MP4FileInfo src/mp4info.cpp:621
    #25 0x5597552bf97d in main util/mp4info.cpp:77
    #26 0x7f33844e4c86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21c86)

SUMMARY: AddressSanitizer: 3 byte(s) leaked in 1 allocation(s).

[enzo1982]

Thank you for reporting this!

The issue is now fixed with commit 0f97a87.

The same issue affected the MP4BytesProperty and MP4StringProperty classes and was caused by the SetCount() methods not freeing the memory belonging to surplus elements when reducing the number of elements.