[FFmpeg-trac] #8275(undetermined:new): heap-buffer-overflow at libavfilter/vf_edgedetect.c:180 in gaussian_blur

[FFmpeg]

#8275: heap-buffer-overflow at libavfilter/vf_edgedetect.c:180 in gaussian_blur
-------------------------------------+-------------------------------------
             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/vf_edgedetect.c:180 in
 gaussian_blur

 I compiled ffmpeg with "--toolchain=clang-asan" to check the memory
 corruption and attached log file.
 How to reproduce:
 {{{
 % ffmpeg_g -y -i $PoC -filter_complex edgedetect -target dv tmp.daud

 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

 {{{
 ==47511==ERROR: AddressSanitizer: heap-buffer-overflow on address
 0x61500001bee2 at pc 0x000000cd9f0e bp 0x7fffffffa710 sp 0x7fffffffa708
 WRITE of size 1 at 0x61500001bee2 thread T0
     #0 0xcd9f0d in gaussian_blur ffmpeg/libavfilter/vf_edgedetect.c:180:20
     #1 0xcd9f0d in filter_frame ffmpeg/libavfilter/vf_edgedetect.c:364
     #2 0x8271b9 in ff_filter_activate_default
 ffmpeg/libavfilter/avfilter.c:1084:11
     #3 0x8271b9 in ff_filter_activate ffmpeg/libavfilter/avfilter.c:1443
     #4 0x8700b2 in push_frame ffmpeg/libavfilter/buffersrc.c:187:15
     #5 0x8700b2 in av_buffersrc_add_frame_internal
 ffmpeg/libavfilter/buffersrc.c:261
     #6 0x86eaf2 in av_buffersrc_add_frame_flags
 ffmpeg/libavfilter/buffersrc.c:170:16
     #7 0x666407 in ifilter_send_frame ffmpeg/fftools/ffmpeg.c:2186:11
     #8 0x666407 in send_frame_to_filters ffmpeg/fftools/ffmpeg.c:2260
     #9 0x607666 in decode_video ffmpeg/fftools/ffmpeg.c:2459:11
     #10 0x607666 in process_input_packet ffmpeg/fftools/ffmpeg.c:2613
     #11 0x644c58 in process_input ffmpeg/fftools/ffmpeg.c:4303:23
     #12 0x5e7157 in transcode_step ffmpeg/fftools/ffmpeg.c:4628:11
     #13 0x5e7157 in transcode ffmpeg/fftools/ffmpeg.c:4682
     #14 0x5db65b in main ffmpeg/fftools/ffmpeg.c:4884:9
     #15 0x7ffff5c93b96 in __libc_start_main /build/glibc-
 OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
     #16 0x41def9 in _start (ffmpeg_asan+0x41def9)

 0x61500001bee2 is located 0 bytes to the right of 418-byte region
 [0x61500001bd40,0x61500001bee2)
 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 0xcda91c in config_props ffmpeg/libavfilter/vf_edgedetect.c:137:29

 SUMMARY: AddressSanitizer: heap-buffer-overflow
 ffmpeg/libavfilter/vf_edgedetect.c:180:20 in gaussian_blur
 Shadow bytes around the buggy address:
   0x0c2a7fffb780: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
   0x0c2a7fffb790: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
   0x0c2a7fffb7a0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
   0x0c2a7fffb7b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x0c2a7fffb7c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 =>0x0c2a7fffb7d0: 00 00 00 00 00 00 00 00 00 00 00 00[02]fa fa fa
   0x0c2a7fffb7e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x0c2a7fffb7f0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
   0x0c2a7fffb800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x0c2a7fffb810: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x0c2a7fffb820: 00 00 00 00 00 00 00 00 00 00 00 00 02 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
 ==47511==ABORTING
 }}}
 Please confirm.
 Thanks

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8275>
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