Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

null pointer reference in gf_m2ts_stream_process_pmt #1378

Closed
cuanduo opened this issue Jan 2, 2020 · 2 comments
Closed

null pointer reference in gf_m2ts_stream_process_pmt #1378

cuanduo opened this issue Jan 2, 2020 · 2 comments

Comments

@cuanduo
Copy link

cuanduo commented Jan 2, 2020

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

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

MP42TS -src $POC -dst-file /dev/null

count_video1.zip
asan output

root@ubuntu:/home/tim/gpac# ../gpac-asan/MP42TS -src crashes/count_video.mp4-signalb-0x198 -dst-file /dev/null
Setting up program ID 1 - send rates: PSI 200 ms PCR 100 ms - PCR offset 0
AddressSanitizer:DEADLYSIGNAL
=================================================================
==115151==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x558236d3d311 bp 0x6080000008a0 sp 0x7ffd7d124a70 T0)
==115151==The signal is caused by a READ memory access.
==115151==Hint: address points to the zero page.
    #0 0x558236d3d310 in gf_m2ts_stream_process_pmt media_tools/m2ts_mux.c:718
    #1 0x558236d4dfd1 in gf_m2ts_mux_table_update_bitrate media_tools/m2ts_mux.c:256
    #2 0x558236d4dfd1 in gf_m2ts_mux_update_config media_tools/m2ts_mux.c:2543
    #3 0x558236bcfffd in main /home/tim/gpac-asan/applications/mp42ts/main.c:2684
    #4 0x7ff116424b6a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x26b6a)
    #5 0x558236bd59c9 in _start (/home/tim/gpac-asan/MP42TS+0x1249c9)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV media_tools/m2ts_mux.c:718 in gf_m2ts_stream_process_pmt
==115151==ABORTING

@aureliendavid
Copy link
Contributor

for this and #1377 my quick and dirty fix was to add a very ugly abort()

error handling is pretty terrible in mp42ts apart from a bunch of asserts (that are ignored when compiling in release mode), return values are rarely checked, etc.

the abort should prevent afl/asan to detect it as a bug, and since it should only happen on very broken files it's not the end of the world, but it's still pretty ugly

if anyone has a better fix be my guest - in the meantime i'm closing the issue, reopen if needed

@Beuc
Copy link

Beuc commented Jan 17, 2020

Hi,

I though I'd mention that abort() leads to mostly the same vulnerability (denial of service, in particular for a service that links to libgpac.so).
See for instance https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-9211

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

3 participants