[FFmpeg-trac] #8276(undetermined:new): heap-buffer-overflow at libavfilter/af_afade.c:436:1 in crossfade_samples_fltp

[FFmpeg]

#8276: heap-buffer-overflow at libavfilter/af_afade.c:436:1 in
crossfade_samples_fltp
-------------------------------------+-------------------------------------
             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-buffer-overflow at libavfilter/af_afade.c:436:1 in
 crossfade_samples_fltp

 I compiled ffmpeg with "--toolchain=clang-asan" to check the memory
 corruption and attached log file.
 How to reproduce:
 {{{
 % ffmpeg_g -y -i $PoC1 -i $PoC2 -filter_complex acrossfade tmp.tta

 ffmpeg version N-95382-g62f4722582 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

 {{{
 ==30297==ERROR: AddressSanitizer: heap-buffer-overflow on address
 0x7fffd8445800 at pc 0x0000016a73a2 bp 0x7fffffffa6a0 sp 0x7fffffffa698
 READ of size 4 at 0x7fffd8445800 thread T0
     #0 0x16a73a1 in crossfade_samples_fltp
 ffmpeg/libavfilter/af_afade.c:436:1
     #1 0x169963c in activate ffmpeg/libavfilter/af_afade.c:504:13
     #2 0x824c3e in ff_filter_activate
 ffmpeg/libavfilter/avfilter.c:1442:38
     #3 0x8700b2 in push_frame ffmpeg/libavfilter/buffersrc.c:187:15
     #4 0x8700b2 in av_buffersrc_add_frame_internal
 ffmpeg/libavfilter/buffersrc.c:261
     #5 0x86eaf2 in av_buffersrc_add_frame_flags
 ffmpeg/libavfilter/buffersrc.c:170:16
     #6 0x666407 in ifilter_send_frame ffmpeg/fftools/ffmpeg.c:2186:11
     #7 0x666407 in send_frame_to_filters ffmpeg/fftools/ffmpeg.c:2260
     #8 0x605543 in decode_audio ffmpeg/fftools/ffmpeg.c:2327:11
     #9 0x605543 in process_input_packet ffmpeg/fftools/ffmpeg.c:2609
     #10 0x64a707 in process_input ffmpeg/fftools/ffmpeg.c:4508:5
     #11 0x5e7157 in transcode_step ffmpeg/fftools/ffmpeg.c:4628:11
     #12 0x5e7157 in transcode ffmpeg/fftools/ffmpeg.c:4682
     #13 0x5db65b in main ffmpeg/fftools/ffmpeg.c:4884:9
     #14 0x7ffff5c93b96 in __libc_start_main /build/glibc-
 OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
     #15 0x41def9 in _start (ffmpeg_asan+0x41def9)

 0x7fffd8445800 is located 0 bytes to the right of 159744-byte region
 [0x7fffd841e800,0x7fffd8445800)
 allocated by thread T0 here:
     #0 0x4de9e8 in posix_memalign (ffmpeg_asan+0x4de9e8)
     #1 0x85924d1 in av_malloc ffmpeg/libavutil/mem.c:87:9
     #2 0x84f927d in av_buffer_alloc ffmpeg/libavutil/buffer.c:72:12
     #3 0x84fdc26 in pool_alloc_buffer ffmpeg/libavutil/buffer.c:313:26
     #4 0x84fdc26 in av_buffer_pool_get ffmpeg/libavutil/buffer.c:349
     #5 0x91c368 in ff_frame_pool_get ffmpeg/libavfilter/framepool.c:261:29
     #6 0x6e2d4c in ff_default_get_audio_buffer
 ffmpeg/libavfilter/audio.c:73:13
     #7 0x82a406 in ff_inlink_consume_samples
 ffmpeg/libavfilter/avfilter.c:1181:11
     #8 0x1699080 in activate ffmpeg/libavfilter/af_afade.c:492:19
     #9 0x824c3e in ff_filter_activate
 ffmpeg/libavfilter/avfilter.c:1442:38
     #10 0x8700b2 in push_frame ffmpeg/libavfilter/buffersrc.c:187:15
     #11 0x8700b2 in av_buffersrc_add_frame_internal
 ffmpeg/libavfilter/buffersrc.c:261
     #12 0x86eaf2 in av_buffersrc_add_frame_flags
 ffmpeg/libavfilter/buffersrc.c:170:16
     #13 0x666407 in ifilter_send_frame ffmpeg/fftools/ffmpeg.c:2186:11
     #14 0x666407 in send_frame_to_filters ffmpeg/fftools/ffmpeg.c:2260
     #15 0x605543 in decode_audio ffmpeg/fftools/ffmpeg.c:2327:11
     #16 0x605543 in process_input_packet ffmpeg/fftools/ffmpeg.c:2609
     #17 0x64a707 in process_input ffmpeg/fftools/ffmpeg.c:4508:5
     #18 0x5e7157 in transcode_step ffmpeg/fftools/ffmpeg.c:4628:11
     #19 0x5e7157 in transcode ffmpeg/fftools/ffmpeg.c:4682
     #20 0x5db65b in main ffmpeg/fftools/ffmpeg.c:4884:9
     #21 0x7ffff5c93b96 in __libc_start_main /build/glibc-
 OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310

 SUMMARY: AddressSanitizer: heap-buffer-overflow
 ffmpeg/libavfilter/af_afade.c:436:1 in crossfade_samples_fltp
 Shadow bytes around the buggy address:
   0x10007b080ab0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x10007b080ac0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x10007b080ad0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x10007b080ae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x10007b080af0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 =>0x10007b080b00:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x10007b080b10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x10007b080b20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x10007b080b30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x10007b080b40: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x10007b080b50: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
 Shadow byte legend (one shadow byte represents 8 application bytes):
   Addressable:           00
   Partially addressable: 01 02 03 04 05 06 07
   Heap left redzone:       fa
   Freed heap region:       fd
   Stack left redzone:      f1
   Stack mid redzone:       f2
   Stack right redzone:     f3
   Stack after return:      f5
   Stack use after scope:   f8
   Global redzone:          f9
   Global init order:       f6
   Poisoned by user:        f7
   Container overflow:      fc
   Array cookie:            ac
   Intra object redzone:    bb
   ASan internal:           fe
   Left alloca redzone:     ca
   Right alloca redzone:    cb
 ==30297==ABORTING


 }}}
 Please confirm.
 Thanks

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8276>
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