[FFmpeg-trac] #8270(undetermined:new): left shift of negative value at libavfilter/vf_mestimate.c:109
FFmpeg
trac at avcodec.org
Mon Oct 14 04:50:41 EEST 2019
#8270: left shift of negative value at libavfilter/vf_mestimate.c:109
-------------------------------------+-------------------------------------
Reporter: Suhwan | Type: defect
Status: new | Priority: normal
Component: | Version: git-
undetermined | master
Keywords: ubsan | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug:
There're 2 left shift of negative value at libavfilter/vf_mestimate.c:109
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 mestimate -target dv50 -loglevel 0
tmp.siff
ffmpeg version N-95343-ge835a9d302 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_mestimate.c:109:107: runtime error: left shift of negative
value -1
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
libavfilter/vf_mestimate.c:109:107 in
libavfilter/vf_mestimate.c:109:148: runtime error: left shift of negative
value -1
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
libavfilter/vf_mestimate.c:109:148 in
}}}
Please confirm.
Thanks
--
Ticket URL: <https://trac.ffmpeg.org/ticket/8270>
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