Project: gpac (gpac/gpac), language: c++
Vulnerability instance: gpac.cve-2020-35979
Sanitizer: address

================= Bug Report (1/1) ==================
## Source: GitHub Issue
## URL: https://github.com/gpac/gpac/issues/1662
## Description:
Issue: gpac/gpac#1662
Title: AddressSanitizer: heap-buffer-overflow in gp_rtp_builder_do_avc ietf/rtp_pck_mpeg4.c:436
State: closed
Created by: Clingto
Created at: 2020-12-15 12:02:59+00:00

Issue Body:
System info:  
Ubuntu 16.04.6 LTS, X64, gcc 5.4.0, gpac (latest master c4f8bc6e and latest V1.0.1 d8538e8)  
I think it is probably due to an imcomplete fix of  [#1483](https://github.com/gpac/gpac/issues/1483) 

Compile Command:
```
$ CC="gcc -fsanitize=address -g" CXX="g++ -fsanitize=address -g" ./configure --static-mp4box --extra-ldflags="-ldl -g"
$ make
```
Run Command:
```
$ MP4Box -hint $gp_rtp_builder_do_avc-hepo -out /dev/null 
```
POC file:  
https://github.com/Clingto/POC/blob/master/gpac-MP4Box/gpac-c4f8bc6e_poc/gp_rtp_builder_do_avc-hepo


ASAN info:
```C
==39148==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60300000dca9 at pc 0x000000fe1693 bp 0x7ffc75309fc0 sp 0x7ffc75309fb0
READ of size 1 at 0x60300000dca9 thread T0
    #0 0xfe1692 in gp_rtp_builder_do_avc ietf/rtp_pck_mpeg4.c:436
    #1 0x92b813 in gf_hinter_track_process media_tools/isom_hinter.c:796
    #2 0x418d5d in HintFile /opt/data/yyp/fuzzsequence/test/0-day/SRC_asan/applications/mp4box/main.c:1446
    #3 0x42bdc7 in mp4boxMain /opt/data/yyp/fuzzsequence/test/0-day/SRC_asan/applications/mp4box/main.c:6641
    #4 0x7fac0705783f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)
    #5 0x417638 in _start (/opt/data/yyp/fuzzsequence/test/0-day/SRC_asan/build/bin/MP4Box+0x417638)

0x60300000dca9 is located 0 bytes to the right of 25-byte region [0x60300000dc90,0x60300000dca9)
allocated by thread T0 here:
    #0 0x7fac07fff602 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x7b69e5 in Media_GetSample isomedia/media.c:573
    #2 0x7602dc in gf_isom_get_sample_ex isomedia/isom_read.c:1808
    #3 0x92b36d in gf_hinter_track_process media_tools/isom_hinter.c:721
    #4 0x418d5d in HintFile /opt/data/yyp/fuzzsequence/test/0-day/SRC_asan/applications/mp4box/main.c:1446
    #5 0x42bdc7 in mp4boxMain /opt/data/yyp/fuzzsequence/test/0-day/SRC_asan/applications/mp4box/main.c:6641
    #6 0x7fac0705783f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)

SUMMARY: AddressSanitizer: heap-buffer-overflow ietf/rtp_pck_mpeg4.c:436 gp_rtp_builder_do_avc
Shadow bytes around the buggy address:
  0x0c067fff9b40: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff9b50: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff9b60: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff9b70: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff9b80: fa fa fa fa fa fa fa fa fa fa fa fa 00 00 04 fa
=>0x0c067fff9b90: fa fa 00 00 00[01]fa fa fd fd fd fa fa fa fd fd
  0x0c067fff9ba0: fd fa fa fa fd fd fd fa fa fa fd fd fd fa fa fa
  0x0c067fff9bb0: fd fd fd fa fa fa fd fd fd fa fa fa fd fd fd fa
  0x0c067fff9bc0: fa fa fd fd fd fa fa fa fd fd fd fa fa fa fd fd
  0x0c067fff9bd0: fd fa fa fa fd fd fd fa fa fa fd fd fd fa fa fa
  0x0c067fff9be0: fd fd fd fa fa fa fd fd fd fa fa fa fd fd fd 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
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  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
==39148==ABORTING
```
Addition: This bug was found with our fuzzer, which is based on AFL. Our fuzzer is developed by Yuanpingyu(cfenicey@gmail.com) 、Xiangkun Jia(xiangkun@iscas.ac.cn) 、Marsman1996(lqliuyuwei@outlook.com) and Yanhao.


Build script:
#!/bin/bash -eu
# Minimized build script with only core build commands
set -eu
./configure --static-build --extra-cflags="${CFLAGS}" --extra-ldflags="${CFLAGS}"
make -j$(nproc)

Dockerfile:
FROM hwiwonlee/secb.base:latest
RUN apt-get update && apt-get install -y build-essential pkg-config libz-dev
RUN git clone https://github.com/gpac/gpac gpac
RUN git -C gpac checkout 5aba27604d957e960d8069d85ccaf868f8a7b07a
WORKDIR $SRC/gpac
COPY build.sh $SRC/

Additional files:
filename: fuzz_parse.c
content: /* Copyright 2021 Google LLC
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
      http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#include <stdio.h>
#include <unistd.h>

#include <gpac/internal/isomedia_dev.h>
#include <gpac/constants.h>

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
    char filename[256];
    sprintf(filename, "/tmp/libfuzzer.%d", getpid());

    FILE *fp = fopen(filename, "wb");
    if (!fp) {
        return 0;
    }
    fwrite(data, size, 1, fp);
    fclose(fp);

    GF_ISOFile *movie = NULL;
    movie = gf_isom_open_file(filename, GF_ISOM_OPEN_READ_DUMP, NULL);
    if (movie != NULL) {
        gf_isom_close(movie);
    }
    unlink(filename);
    return 0;
}