Opened 3 years ago

Closed 10 months ago

#8270 closed defect (fixed)

left shift of negative value at libavfilter/vf_mestimate.c:109

Reported by: Suhwan Owned by:
Priority: normal Component: undetermined
Version: git-master Keywords: ubsan
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

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

Attachments (1)

PoC_vf_mestimate.png00 (287 bytes ) - added by Suhwan 3 years ago.
poc

Download all attachments as: .zip

Change History (2)

by Suhwan, 3 years ago

Attachment: PoC_vf_mestimate.png00 added

poc

comment:1 by Elon Musk, 10 months ago

Resolution: fixed
Status: newclosed
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