heap-buffer-overflow at libavfilter/vf_floodfill.c
Summary of the bug:
There is a heap-buffer-overflow at libavfilter/vf_floodfill.c:333:45
==48454==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x63000000e500 at pc 0x000002605a3c bp 0x7fff562c7d50 sp 0x7fff562c7d48
WRITE of size 2 at 0x63000000e500 thread T0
#0 0x2605a3b in filter_frame ffmpeg/libavfilter/vf_floodfill.c:333:45
#1 0x113d8c8 in ff_filter_activate_default ffmpeg/libavfilter/avfilter.c:1071:11
#2 0x113d8c8 in ff_filter_activate ffmpeg/libavfilter/avfilter.c:1430
#3 0x125d263 in push_frame ffmpeg/libavfilter/buffersrc.c:187:15
#4 0x125d263 in av_buffersrc_add_frame_internal ffmpeg/libavfilter/buffersrc.c:261
#5 0x1257ecc in av_buffersrc_add_frame_flags ffmpeg/libavfilter/buffersrc.c:170:16
#6 0xa427a8 in ifilter_send_frame ffmpeg/fftools/ffmpeg.c:2196:11
#7 0xa427a8 in send_frame_to_filters ffmpeg/fftools/ffmpeg.c:2270
#8 0x8c4e27 in decode_video ffmpeg/fftools/ffmpeg.c:2469:11
#9 0x8c4e27 in process_input_packet ffmpeg/fftools/ffmpeg.c:2623
#10 0x9d5063 in process_input ffmpeg/fftools/ffmpeg.c:4518:5
#11 0x847996 in transcode_step ffmpeg/fftools/ffmpeg.c:4638:11
#12 0x847996 in transcode ffmpeg/fftools/ffmpeg.c:4692
#13 0x81cf5f in main ffmpeg/fftools/ffmpeg.c:4894:9
#14 0x7fd5916a6b96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
#15 0x41def9 in _start (ffmpeg_usan+0x41def9)
0x63000000e500 is located 0 bytes to the right of 57600-byte region [0x630000000400,0x63000000e500)
allocated by thread T0 here:
#0 0x4de9e8 in posix_memalign (ffmpeg_usan+0x4de9e8)
#1 0x1fd86a19 in av_malloc ffmpeg/libavutil/mem.c:87:9
#2 0x1fd86a19 in av_mallocz ffmpeg/libavutil/mem.c:238
#3 0x1fd86a19 in av_calloc ffmpeg/libavutil/mem.c:248
#4 0x2608e4c in config_input ffmpeg/libavfilter/vf_floodfill.c:272:17
SUMMARY: AddressSanitizer: heap-buffer-overflow ffmpeg/libavfilter/vf_floodfill.c:333:45 in filter_frame
How to reproduce:
% ffmpeg_g -stream_loop 5 -y -i $PoC -filter_complex floodfill -target dvd -loglevel 0 -map 0 -vbsf null -c:a:119 dvdsub -disposition:v:62 alias_pix -ab 282k -ac 27 -b:v 590k tmp.mpjpeg
ffmpeg version N-95291-g5345965b3f 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-asan
poc