[FFmpeg-trac] #8287(undetermined:new): left shift of negative value at libavfilter/vf_edgedetect.c:219
FFmpeg
trac at avcodec.org
Wed Oct 16 18:37:09 EEST 2019
#8287: left shift of negative value at libavfilter/vf_edgedetect.c:219
-------------------------------------+-------------------------------------
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 is a left shift of negative value at libavfilter/vf_edgedetect.c:219
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 edgedetect -target dvd -loglevel 0
-map 0 tmp.gxf
ffmpeg version N-95399-g1a0c584abc 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_edgedetect.c:219:12: runtime error: left shift of negative
value -273
Thread 1 "ffmpeg_g" hit Breakpoint 1, 0x00000000004288b0 in
__ubsan::ScopedReport::~ScopedReport() ()
(gdb) bt
#0 0x00000000004288b0 in __ubsan::ScopedReport::~ScopedReport() ()
#1 0x000000000042a9a0 in
handleShiftOutOfBoundsImpl(__ubsan::ShiftOutOfBoundsData*, unsigned long,
unsigned long, __ubsan::ReportOptions) ()
#2 0x000000000042cb41 in __ubsan_handle_shift_out_of_bounds ()
#3 0x0000000000951d7a in get_rounded_direction (gx=727, gy=-273) at
libavfilter/vf_edgedetect.c:219
#4 sobel (w=<optimized out>, dst=<optimized out>, dst_linesize=<optimized
out>, dir=<optimized out>, dir_linesize=<optimized out>, src=<optimized
out>, src_linesize=<optimized out>,
h=<optimized out>) at libavfilter/vf_edgedetect.c:251
#5 filter_frame (inlink=<optimized out>, in=<optimized out>) at
libavfilter/vf_edgedetect.c:372
#6 0x00000000005cfe9d in ff_filter_frame_framed (link=<optimized out>,
frame=0x0) at libavfilter/avfilter.c:1084
#7 ff_filter_frame_to_filter (link=<optimized out>) at
libavfilter/avfilter.c:1232
#8 ff_filter_activate_default (filter=<optimized out>) at
libavfilter/avfilter.c:1281
#9 ff_filter_activate (filter=<optimized out>) at
libavfilter/avfilter.c:1443
#10 0x00000000005f42bf in push_frame (graph=0x93ae5c0) at
libavfilter/buffersrc.c:187
#11 av_buffersrc_add_frame_internal (ctx=<optimized out>, frame=0x93c6bc0,
flags=<optimized out>) at libavfilter/buffersrc.c:261
#12 0x00000000005f2e7e in av_buffersrc_add_frame_flags (ctx=0x93e07c0,
frame=0x93c6bc0, flags=4) at libavfilter/buffersrc.c:170
#13 0x00000000004cad60 in ifilter_send_frame (ifilter=<optimized out>,
frame=<optimized out>) at fftools/ffmpeg.c:2186
#14 send_frame_to_filters (ist=0x93b2f40, decoded_frame=0x93c6bc0) at
fftools/ffmpeg.c:2260
#15 0x00000000004a07bc in decode_video (ist=<optimized out>,
pkt=<optimized out>, got_output=<optimized out>, duration_pts=<optimized
out>, eof=<optimized out>, decode_failed=<optimized out>)
at fftools/ffmpeg.c:2459
#16 process_input_packet (ist=<optimized out>, pkt=<optimized out>,
no_eof=<optimized out>) at fftools/ffmpeg.c:2613
#17 0x00000000004bf0f0 in process_input (file_index=<optimized out>) at
fftools/ffmpeg.c:4508
#18 0x000000000048d5eb in transcode_step () at fftools/ffmpeg.c:4628
#19 transcode () at fftools/ffmpeg.c:4682
#20 0x0000000000487da4 in main (argc=15, argv=<optimized out>) at
fftools/ffmpeg.c:4884
}}}
Please confirm.
Thanks
--
Ticket URL: <https://trac.ffmpeg.org/ticket/8287>
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