Project: gpac (gpac/gpac), language: c++
Vulnerability instance: gpac.cve-2020-6630
Sanitizer: address

================= Bug Report (1/1) ==================
## Source: GitHub Issue
## URL: https://github.com/gpac/gpac/issues/1377
## Description:
Issue: gpac/gpac#1377
Title: null pointer reference in  gf_isom_get_media_data_size
State: closed
Created by: cuanduo
Created at: 2020-01-02 00:45:04+00:00

Issue Body:
Thanks for reporting your issue. Please make sure these boxes are checked before submitting your issue - thank you!

- [ yes] I looked for a similar issue and couldn't find any.
- [ yes] I tried with the latest version of GPAC. Installers available at http://gpac.io/downloads/gpac-nightly-builds/
- [ yes] I give enough information for contributors to reproduce my issue (meaningful title, github labels, platform and compiler, command-line ...). I can share files anonymously with this dropbox: https://www.mediafire.com/filedrop/filedrop_hosted.php?drop=eec9e058a9486fe4e99c33021481d9e1826ca9dbc242a6cfaab0fe95da5e5d95

Detailed guidelines: http://gpac.io/2013/07/16/how-to-file-a-bug-properly/

MP42TS -src $POC -dst-file /dev/null
[count_video.zip](https://github.com/gpac/gpac/files/4014701/count_video.zip)
asan output
```
root@ubuntu:/home/tim/gpac# ../gpac-asan/MP42TS -src crashes/count_video.mp4-signalb-0x0 -dst-file /dev/null
AddressSanitizer:DEADLYSIGNAL
=================================================================
==112791==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000028 (pc 0x55e4a53e12e4 bp 0x602000000370 sp 0x7fffdb37dbe0 T0)
==112791==The signal is caused by a READ memory access.
==112791==Hint: address points to the zero page.
    #0 0x55e4a53e12e3 in gf_isom_get_media_data_size isomedia/isom_read.c:3312
    #1 0x55e4a5391fdd in fill_isom_es_ifce /home/tim/gpac-asan/applications/mp42ts/main.c:620
    #2 0x55e4a5391fdd in open_source /home/tim/gpac-asan/applications/mp42ts/main.c:1518
    #3 0x55e4a53836c0 in parse_args /home/tim/gpac-asan/applications/mp42ts/main.c:2260
    #4 0x55e4a53836c0 in main /home/tim/gpac-asan/applications/mp42ts/main.c:2465
    #5 0x7f9a8b98ab6a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x26b6a)
    #6 0x55e4a53899c9 in _start (/home/tim/gpac-asan/MP42TS+0x1249c9)

```



Comments:
Comment by aureliendavid on 2020-01-08 15:42:16+00:00:
see #1378

Attachments:
https://github.com/gpac/gpac/files/4014701/count_video.zip

Commit References:
eec9e058a9486fe4e99c33021481d9e1826ca9db

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 6b4ab401297be43b57f9eddd675971a8a5feab44
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;
}