[FFmpeg-trac] #8249(undetermined:new): stack-buffer-overflow at libavfilter/vf_signalstats.c:634

[FFmpeg]

#8249: stack-buffer-overflow at libavfilter/vf_signalstats.c:634
-------------------------------------+-------------------------------------
             Reporter:  Suhwan       |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:  asan         |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 There is a stack-buffer-overflow at libavfilter/vf_signalstats.c:634 in
 filter_frame8
 I compiled ffmpeg with "--toolchain=clang-asan" to check the heap buffer
 overflow and attached log file.

 How to reproduce:
 {{{
 % ffmpeg_g -t 1 -stream_loop 7 -y -r 120 -i $PoC -filter_complex
 signalstats -target dvd -loglevel 99 -c:a:112 y41p -c:v:143 vorbis
 -disposition:s:2 pcm_s8_planar -disposition:v:61 prores_aw -r 44 -ab 633k
 -strict 3 tmp.aac

 ffmpeg version N-95314-g1331e00179 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-asan
 }}}

 Here's ASAN log

 {{{
 =================================================================
 ==14934==ERROR: AddressSanitizer: stack-buffer-overflow on address
 0x7fffffffa020 at pc 0x000001294ae2 bp 0x7fffffff8c10 sp 0x7fffffff8c08
 READ of size 4 at 0x7fffffffa020 thread T0
     #0 0x1294ae1 in filter_frame8
 ffmpeg/libavfilter/vf_signalstats.c:634:42
     #1 0x827289 in ff_filter_activate_default
 ffmpeg/libavfilter/avfilter.c:1071:11
     #2 0x827289 in ff_filter_activate ffmpeg/libavfilter/avfilter.c:1430
     #3 0x870182 in push_frame ffmpeg/libavfilter/buffersrc.c:187:15
     #4 0x870182 in av_buffersrc_add_frame_internal
 ffmpeg/libavfilter/buffersrc.c:261
     #5 0x86ebc2 in av_buffersrc_add_frame_flags
 ffmpeg/libavfilter/buffersrc.c:170:16
     #6 0x666867 in ifilter_send_frame ffmpeg/fftools/ffmpeg.c:2196:11
     #7 0x666867 in send_frame_to_filters ffmpeg/fftools/ffmpeg.c:2270
     #8 0x6075f7 in decode_video ffmpeg/fftools/ffmpeg.c:2469:11
     #9 0x6075f7 in process_input_packet ffmpeg/fftools/ffmpeg.c:2623
     #10 0x64ab67 in process_input ffmpeg/fftools/ffmpeg.c:4518:5
     #11 0x5e7157 in transcode_step ffmpeg/fftools/ffmpeg.c:4638:11
     #12 0x5e7157 in transcode ffmpeg/fftools/ffmpeg.c:4692
     #13 0x5db65b in main ffmpeg/fftools/ffmpeg.c:4894:9
     #14 0x7ffff5c93b96 in __libc_start_main /build/glibc-
 OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
     #15 0x41def9 in _start (ffmpeg/ffmpeg_g+0x41def9)

 Address 0x7fffffffa020 is located in stack of thread T0 at offset 5120 in
 frame
     #0 0x128d7ef in filter_frame8 ffmpeg/libavfilter/vf_signalstats.c:550

   This frame has 11 object(s):
     [32, 40) 'in.addr'
     [64, 192) 'metabuf' (line 559)
     [224, 1248) 'histy' (line 560)
     [1376, 2400) 'histu' (line 560)
     [2528, 3552) 'histv' (line 560)
     [3680, 5120) 'histhue' (line 560) <== Memory access at offset 5120
 overflows this variable
     [5248, 6272) 'histsat' (line 560)
     [6400, 6412) 'filtot' (line 579)
     [6432, 6456) 'td_huesat' (line 588)
     [6496, 6512) 'td' (line 644)
     [6528, 6656) 'metaname' (line 755)
 HINT: this may be a false positive if your program uses some custom stack
 unwind mechanism or swapcontext
       (longjmp and C++ exceptions *are* supported)
 SUMMARY: AddressSanitizer: stack-buffer-overflow
 ffmpeg/libavfilter/vf_signalstats.c:634:42 in filter_frame8

 }}}
 Please confirm.
 Thanks

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8249>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker