## Description
There is a heap buffer overflow detected by AddressSanitizer

## System info
```
Ubuntu 20.04.2 LTS
clang version 12.0.0-++20210402082642+04ba60cfe598-1~exp1~20210402063359.71
MP4Box - GPAC version 1.1.0-DEV-rev1727-g8be34973d-master
```

## Build command
```
./configure --static-mp4box --prefix=`realpath ./install` --enable-sanitizer --cc=clang --cxx=clang++
```

## crash command
```
MP4Box -frag 0 -out /dev/null poc_file
```

## Pocs

[poc.zip](https://github.com/gpac/gpac/files/8020690/poc.zip)


## Crash output

```
==4028==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000003372 at pc 0x000000499077 bp 0x7ffce0570950 sp 0x7ffce0570118
READ of size 3 at 0x602000003372 thread T0
    #0 0x499076 in __asan_memcpy (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x499076)
    #1 0x548483 in gf_bs_write_data/programs/mp4box/builds/build10/src/utils/bitstream.c:1045:4
    #2 0x87195e in gf_isom_fragment_add_sample/programs/mp4box/builds/build10/src/isomedia/movie_fragments.c:2760:9
    #3 0xd7c9b7 in mp4_mux_process_sample/programs/mp4box/builds/build10/src/filters/mux_isom.c:4105:9
    #4 0xd727e8 in mp4_mux_process_fragmented/programs/mp4box/builds/build10/src/filters/mux_isom.c:5637:8
    #5 0xd6d05f in mp4_mux_process/programs/mp4box/builds/build10/src/filters/mux_isom.c:6071:14
    #6 0xb7d866 in gf_filter_process_task/programs/mp4box/builds/build10/src/filter_core/filter.c:2555:7
    #7 0xb5e41b in gf_fs_thread_proc/programs/mp4box/builds/build10/src/filter_core/filter_session.c:1793:3
    #8 0xb5d2c4 in gf_fs_run/programs/mp4box/builds/build10/src/filter_core/filter_session.c:2037:2
    #9 0x911200 in gf_media_fragment_file/programs/mp4box/builds/build10/src/media_tools/isom_tools.c:3821:6
    #10 0x4e6fcc in mp4boxMain/programs/mp4box/builds/build10/applications/mp4box/main.c:6455:7
    #11 0x7f0e712900b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #12 0x41ea6d in _start (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x41ea6d)

0x602000003372 is located 0 bytes to the right of 2-byte region [0x602000003370,0x602000003372)
allocated by thread T0 here:
    #0 0x499ccd in malloc (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x499ccd)
    #1 0x155f40e in gf_filter_pck_new_alloc_internal/programs/mp4box/builds/build10/src/filter_core/filter_pck.c:151:15
    #2 0xd0481d in isoffin_process/programs/mp4box/builds/build10/src/filters/isoffin_read.c:1343:12
    #3 0xb7d866 in gf_filter_process_task/programs/mp4box/builds/build10/src/filter_core/filter.c:2555:7
    #4 0xb5e41b in gf_fs_thread_proc/programs/mp4box/builds/build10/src/filter_core/filter_session.c:1793:3
    #5 0xb5d2c4 in gf_fs_run/programs/mp4box/builds/build10/src/filter_core/filter_session.c:2037:2
    #6 0x911200 in gf_media_fragment_file/programs/mp4box/builds/build10/src/media_tools/isom_tools.c:3821:6
    #7 0x4e6fcc in mp4boxMain/programs/mp4box/builds/build10/applications/mp4box/main.c:6455:7
    #8 0x7f0e712900b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

SUMMARY: AddressSanitizer: heap-buffer-overflow (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x499076) in __asan_memcpy
Shadow bytes around the buggy address:
  0x0c047fff8610: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8620: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8630: fa fa fd fd fa fa fd fd fa fa fd fd fa fa 00 00
  0x0c047fff8640: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8650: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
=>0x0c047fff8660: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa[02]fa
  0x0c047fff8670: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8680: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8690: fa fa fd fd fa fa 00 00 fa fa 04 fa fa fa 00 00
  0x0c047fff86a0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff86b0: fa fa 00 00 fa fa 00 fa fa fa 00 00 fa fa 00 00
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
  Shadow gap:              cc
==4028==ABORTING
```
There is a heap buffer overflow detected by AddressSanitizer
This is a GitHub Issue
repo:gpac
owner:gpac
Title : There is a heap buffer overflow detected by AddressSanitizer
Issue date:

--- start body ---
## Description
There is a heap buffer overflow detected by AddressSanitizer

## System info
```
Ubuntu 20.04.2 LTS
clang version 12.0.0-++20210402082642+04ba60cfe598-1~exp1~20210402063359.71
MP4Box - GPAC version 1.1.0-DEV-rev1727-g8be34973d-master
```

## Build command
```
./configure --static-mp4box --prefix=`realpath ./install` --enable-sanitizer --cc=clang --cxx=clang++
```

## crash command
```
MP4Box -frag 0 -out /dev/null poc_file
```

## Pocs

[poc.zip](https://github.com/gpac/gpac/files/8020690/poc.zip)


## Crash output

```
==4028==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000003372 at pc 0x000000499077 bp 0x7ffce0570950 sp 0x7ffce0570118
READ of size 3 at 0x602000003372 thread T0
    #0 0x499076 in __asan_memcpy (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x499076)
    #1 0x548483 in gf_bs_write_data/programs/mp4box/builds/build10/src/utils/bitstream.c:1045:4
    #2 0x87195e in gf_isom_fragment_add_sample/programs/mp4box/builds/build10/src/isomedia/movie_fragments.c:2760:9
    #3 0xd7c9b7 in mp4_mux_process_sample/programs/mp4box/builds/build10/src/filters/mux_isom.c:4105:9
    #4 0xd727e8 in mp4_mux_process_fragmented/programs/mp4box/builds/build10/src/filters/mux_isom.c:5637:8
    #5 0xd6d05f in mp4_mux_process/programs/mp4box/builds/build10/src/filters/mux_isom.c:6071:14
    #6 0xb7d866 in gf_filter_process_task/programs/mp4box/builds/build10/src/filter_core/filter.c:2555:7
    #7 0xb5e41b in gf_fs_thread_proc/programs/mp4box/builds/build10/src/filter_core/filter_session.c:1793:3
    #8 0xb5d2c4 in gf_fs_run/programs/mp4box/builds/build10/src/filter_core/filter_session.c:2037:2
    #9 0x911200 in gf_media_fragment_file/programs/mp4box/builds/build10/src/media_tools/isom_tools.c:3821:6
    #10 0x4e6fcc in mp4boxMain/programs/mp4box/builds/build10/applications/mp4box/main.c:6455:7
    #11 0x7f0e712900b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #12 0x41ea6d in _start (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x41ea6d)

0x602000003372 is located 0 bytes to the right of 2-byte region [0x602000003370,0x602000003372)
allocated by thread T0 here:
    #0 0x499ccd in malloc (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x499ccd)
    #1 0x155f40e in gf_filter_pck_new_alloc_internal/programs/mp4box/builds/build10/src/filter_core/filter_pck.c:151:15
    #2 0xd0481d in isoffin_process/programs/mp4box/builds/build10/src/filters/isoffin_read.c:1343:12
    #3 0xb7d866 in gf_filter_process_task/programs/mp4box/builds/build10/src/filter_core/filter.c:2555:7
    #4 0xb5e41b in gf_fs_thread_proc/programs/mp4box/builds/build10/src/filter_core/filter_session.c:1793:3
    #5 0xb5d2c4 in gf_fs_run/programs/mp4box/builds/build10/src/filter_core/filter_session.c:2037:2
    #6 0x911200 in gf_media_fragment_file/programs/mp4box/builds/build10/src/media_tools/isom_tools.c:3821:6
    #7 0x4e6fcc in mp4boxMain/programs/mp4box/builds/build10/applications/mp4box/main.c:6455:7
    #8 0x7f0e712900b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

SUMMARY: AddressSanitizer: heap-buffer-overflow (/zhengjie/cmdline-fuzz/programs/mp4box/builds/build10/bin/gcc/MP4Box+0x499076) in __asan_memcpy
Shadow bytes around the buggy address:
  0x0c047fff8610: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8620: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8630: fa fa fd fd fa fa fd fd fa fa fd fd fa fa 00 00
  0x0c047fff8640: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8650: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
=>0x0c047fff8660: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa[02]fa
  0x0c047fff8670: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8680: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8690: fa fa fd fd fa fa 00 00 fa fa 04 fa fa fa 00 00
  0x0c047fff86a0: fa fa 00 00 fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff86b0: fa fa 00 00 fa fa 00 fa fa fa 00 00 fa fa 00 00
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
  Shadow gap:              cc
==4028==ABORTING
```
--- end body ---
