Opened 5 years ago

Closed 4 years ago

#8167 closed defect (fixed)

left shift of negative value bugs in libavcodec/motion_est_template.c

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

Description

Summary of the bug:
There're two left shift of negative value bugs in libavcodec/motion_est_template.c

libavcodec/motion_est_template.c:160:14: runtime error: left shift of negative value -1
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior libavcodec/motion_est_template.c:160:14 in 
libavcodec/motion_est_template.c:161:14: runtime error: left shift of negative value -2
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior libavcodec/motion_est_template.c:161:14 in

How to reproduce:

% ./ffmpeg_g -t 2 -y -r 90 -i Freh7_B.264 -map 0 -vframes 120 -aframes 84 -r 79 -ab 847k -ac 12 -b:v 283k output/tmp.h261

ffmpeg version N-94943-g1db6e47e85
built on ubuntu 18.04 with clang-6 and UBSAN option.

Attachments (2)

gdb-motion​ (30.8 KB ) - added by Suhwan 5 years ago.
Freh7_B.264​ (567.3 KB ) - added by Suhwan 5 years ago.
poc

Download all attachments as: .zip

Change History (3)

by Suhwan, 5 years ago

Attachment: gdb-motion​ added

by Suhwan, 5 years ago

Attachment: Freh7_B.264​ added

poc

comment:1 by Carl Eugen Hoyos, 4 years ago

Component: undetermined → avcodec
Resolution: → fixed
Status: new → closed

Fixed by Michael in e13eee37ee3268b0a985ddc74a9bde0179bd553c

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