signed integer overflow at libavfilter/vf_convolution.c:139

[Suhwan]

Summary of the bug:
There are 3 signed integer overflow and 1 outside the range of representable values of type 'int' at libavfilter/vf_convolution.c:139

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 roberts -target dvd -loglevel 0 tmp.subviewer1

ffmpeg version N-95336-g4f4334bcbc 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_convolution.c:139:48: runtime error: signed integer overflow: -65535 * -65535 cannot be represented in type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior libavfilter/vf_convolution.c:139:48 in 
libavfilter/vf_convolution.c:139:36: runtime error: signed integer overflow: 65535 * 65535 cannot be represented in type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior libavfilter/vf_convolution.c:139:36 in 
libavfilter/vf_convolution.c:139:26: runtime error: -nan is outside the range of representable values of type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior libavfilter/vf_convolution.c:139:26 in 
libavfilter/vf_convolution.c:139:42: runtime error: signed integer overflow: 1712056129 + 1886425489 cannot be represented in type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior libavfilter/vf_convolution.c:139:42 in

Please confirm.
Thanks

[Suhwan]

poc