[FFmpeg-trac] #8288(undetermined:new): load of null pointer of type 'const uint16_t' at libavfilter/vf_colorchannelmixer.c:187

[FFmpeg]

#8288: load of null pointer of type 'const uint16_t' at
libavfilter/vf_colorchannelmixer.c:187
-------------------------------------+-------------------------------------
             Reporter:  Suhwan       |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:  ubsan        |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 There is a load of null pointer of type 'const uint16_t' at
 libavfilter/vf_colorchannelmixer.c:187

 I compiled ffmpeg with "--toolchain=clang-usan" to check the undefined-
 behaviours and attached log file.
 How to reproduce:
 {{{
 % ffmpeg_g -y -i $PoC -filter_complex colorchannelmixer -loglevel 0
 tmp.dnxhd

 ffmpeg version N-95399-g1a0c584abc Copyright (c) 2000-2019 the FFmpeg
 developers
 built with clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
 configuration: --cc=clang --cxx=clang++ --ld=clang --enable-debug
 --toolchain=clang-usan
 }}}

 Here's UBSAN log

 {{{
 libavfilter/vf_colorchannelmixer.c:187:34: runtime error: load of null
 pointer of type 'const uint16_t' (aka 'const unsigned short')
 [Switching to Thread 0x7ffff5652700 (LWP 47209)]

 Thread 2 "ffmpeg_g" hit Breakpoint 1, 0x00000000004288b0 in
 __ubsan::ScopedReport::~ScopedReport() ()
 (gdb) bt
 #0  0x00000000004288b0 in __ubsan::ScopedReport::~ScopedReport() ()
 #1  0x000000000042bfee in
 handleTypeMismatchImpl(__ubsan::TypeMismatchData*, unsigned long,
 __ubsan::ReportOptions) ()
 #2  0x000000000042c841 in __ubsan_handle_type_mismatch_v1 ()
 #3  0x00000000007c82df in filter_slice_rgba16_planar (ctx=<optimized out>,
 arg=<optimized out>, jobnr=<optimized out>, nb_jobs=<optimized out>,
 have_alpha=<optimized out>, depth=<optimized out>)
     at libavfilter/vf_colorchannelmixer.c:187
 #4  filter_slice_gbrp10 (ctx=<optimized out>, arg=<optimized out>,
 jobnr=<optimized out>, nb_jobs=<optimized out>) at
 libavfilter/vf_colorchannelmixer.c:239
 #5  0x0000000000663445 in worker_func (priv=0x93f3d40, jobnr=0,
 threadnr=<optimized out>, nb_jobs=<optimized out>, nb_threads=<optimized
 out>) at libavfilter/pthread.c:50
 #6  0x00000000059d4778 in run_jobs (ctx=0x93f0380) at
 libavutil/slicethread.c:61
 #7  0x00000000059d3586 in thread_worker (v=<optimized out>) at
 libavutil/slicethread.c:85
 #8  0x00007ffff668e6db in start_thread (arg=0x7ffff5652700) at
 pthread_create.c:463
 #9  0x00007ffff5d9388f in clone () at
 ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

 }}}
 Please confirm.
 Thanks

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8288>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker