[FFmpeg-trac] #8248(undetermined:new): heap-use-after-free at libavfilter/vf_minterpolate.c:304

[FFmpeg]

#8248: heap-use-after-free at libavfilter/vf_minterpolate.c:304
-------------------------------------+-------------------------------------
             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 heap-use-after-free at libavfilter/vf_minterpolate.c:304 in
 get_sbad_ob
 I compiled ffmpeg with "--toolchain=clang-asan" to check the heap buffer
 overflow and attached log file.

 How to reproduce:
 {{{
 % ffmpeg_g -stream_loop 17 -y -r 94 -i $PoC -filter_complex minterpolate
 -target vcd -loglevel 99 -c:s:18 pcm_alaw -c:a:103 sonicls -vframes 85
 -aframes 36 -strict 0 tmp.gif

 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

 {{{
 =================================================================
 ==18982==ERROR: AddressSanitizer: heap-use-after-free on address
 0x619000004470 at pc 0x000001021720 bp 0x7fffffffa0d0 sp 0x7fffffffa0c8
 READ of size 1 at 0x619000004470 thread T0
     #0 0x102171f in get_sbad_ob
 ffmpeg/libavfilter/vf_minterpolate.c:304:21
     #1 0x1b12270 in ff_me_search_epzs
 ffmpeg/libavfilter/motion_estimation.c:346:5
     #2 0x1008839 in search_mv ffmpeg/libavfilter/vf_minterpolate.c:515:13
     #3 0xfe94eb in bilateral_me
 ffmpeg/libavfilter/vf_minterpolate.c:585:13
     #4 0xfe94eb in inject_frame ffmpeg/libavfilter/vf_minterpolate.c:785
     #5 0xfdfc0d in filter_frame
 ffmpeg/libavfilter/vf_minterpolate.c:1180:15
     #6 0x827289 in ff_filter_activate_default
 ffmpeg/libavfilter/avfilter.c:1071:11
     #7 0x827289 in ff_filter_activate ffmpeg/libavfilter/avfilter.c:1430
     #8 0x870182 in push_frame ffmpeg/libavfilter/buffersrc.c:187:15
     #9 0x870182 in av_buffersrc_add_frame_internal
 ffmpeg/libavfilter/buffersrc.c:261
     #10 0x86ebc2 in av_buffersrc_add_frame_flags
 ffmpeg/libavfilter/buffersrc.c:170:16
     #11 0x666867 in ifilter_send_frame ffmpeg/fftools/ffmpeg.c:2196:11
     #12 0x666867 in send_frame_to_filters ffmpeg/fftools/ffmpeg.c:2270
     #13 0x6075f7 in decode_video ffmpeg/fftools/ffmpeg.c:2469:11
     #14 0x6075f7 in process_input_packet ffmpeg/fftools/ffmpeg.c:2623
     #15 0x64ab67 in process_input ffmpeg/fftools/ffmpeg.c:4518:5
     #16 0x5e7157 in transcode_step ffmpeg/fftools/ffmpeg.c:4638:11
     #17 0x5e7157 in transcode ffmpeg/fftools/ffmpeg.c:4692
     #18 0x5db65b in main ffmpeg/fftools/ffmpeg.c:4894:9
     #19 0x7ffff5c93b96 in __libc_start_main /build/glibc-
 OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
     #20 0x41def9 in _start (ffmpeg/ffmpeg_g+0x41def9)

 0x619000004470 is located 752 bytes inside of 1064-byte region
 [0x619000004180,0x6190000045a8)
 freed by thread T0 here:
     #0 0x4ddbe0 in __interceptor_free.localalias.0
 (ffmpeg/ffmpeg_g+0x4ddbe0)
     #1 0x1d67a88 in dump_stream_format ffmpeg/libavformat/dump.c:492:5
     #2 0x1d6571e in av_dump_format ffmpeg/libavformat/dump.c:659:13

 previously allocated by thread T0 here:
     #0 0x4de9e8 in posix_memalign (ffmpeg/ffmpeg_g+0x4de9e8)
     #1 0x8564fb1 in av_malloc ffmpeg/libavutil/mem.c:87:9
     #2 0x46096ba in avcodec_alloc_context3
 ffmpeg/libavcodec/options.c:158:28
     #3 0x1d6571e in av_dump_format ffmpeg/libavformat/dump.c:659:13

 SUMMARY: AddressSanitizer: heap-use-after-free
 ffmpeg/libavfilter/vf_minterpolate.c:304:21 in get_sbad_ob
 }}}
 Please confirm.
 Thanks

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8248>
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