Project: gpac (gpac/gpac), language: c++
Vulnerability instance: gpac.cve-2019-20631
Sanitizer: address

================= Bug Report (1/1) ==================
## Source: GitHub Issue
## URL: https://github.com/gpac/gpac/issues/1270
## Description:
Issue: gpac/gpac#1270
Title: SEGV on unknown address on gf_list_count
State: closed
Created by: strongcourage
Created at: 2019-07-06 00:11:01+00:00

Issue Body:
Hi,
Our fuzzer found an UAF on MP4Box (the latest commit 987169b on master).
PoC: https://github.com/strongcourage/PoCs/blob/master/gpac_987169b/PoC_segv_gf_list_count
Command: MP4Box -info $PoC
ASAN says:
~~~
==19963==ERROR: AddressSanitizer: SEGV on unknown address 0x00047fff8001 (pc 0x00000047a43d bp 0x60800000bfa0 sp 0x7ffe5b9765b0 T0)
    #0 0x47a43c in gf_list_count /home/dungnguyen/gueb-testing/gpac-head/src/utils/list.c:641
    #1 0x9809d4 in gf_m2ts_process_pmt /home/dungnguyen/gueb-testing/gpac-head/src/media_tools/mpegts.c:2185
    #2 0x970944 in gf_m2ts_section_complete /home/dungnguyen/gueb-testing/gpac-head/src/media_tools/mpegts.c:1610
    #3 0x971fa2 in gf_m2ts_gather_section /home/dungnguyen/gueb-testing/gpac-head/src/media_tools/mpegts.c:1740
    #4 0x97991c in gf_m2ts_process_packet /home/dungnguyen/gueb-testing/gpac-head/src/media_tools/mpegts.c:3446
    #5 0x97991c in gf_m2ts_process_data /home/dungnguyen/gueb-testing/gpac-head/src/media_tools/mpegts.c:3507
    #6 0x986f65 in gf_m2ts_probe_file /home/dungnguyen/gueb-testing/gpac-head/src/media_tools/mpegts.c:4641
    #7 0x963fa9 in gf_media_import /home/dungnguyen/gueb-testing/gpac-head/src/media_tools/media_import.c:10998
    #8 0x45b475 in convert_file_info /home/dungnguyen/gueb-testing/gpac-head/applications/mp4box/fileimport.c:124
    #9 0x43ac0c in mp4boxMain /home/dungnguyen/gueb-testing/gpac-head/applications/mp4box/main.c:4804
    #10 0x7ff2747fe82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #11 0x421eb8 in _start (/home/dungnguyen/PoCs/gpac_987169b/MP4Box-asan+0x421eb8)
~~~
Thanks,
Manh Dung


Comments:
Comment by jeanlf on 2019-07-07 16:00:39+00:00:
this was fixed after fixing  #1266, #1267, #1268, #1269,

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 4b9c25bf88498cb8adac0ee675819eb0da1dc863
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;
}