heap-buffer-overflow at libavfilter/f_reverse.c:269:26 in areverse_request_frame in FFmpeg

[ZengYunxiang]

Summary of the bug:

Dear developers,

We found the following heap-buffer-overflow bug on FFmpeg(version N-113007-g8d24a28d06) when using areverse filter, please confirm.

The poc file(poc16ffmpeg) will be attached to this ticket.

How to reproduce:

git clone https://github.com/FFmpeg/FFmpeg.git ffmpeg
cd ffmpeg
./configure --cc=clang --cxx=clang++ --ld=clang --enable-debug --toolchain=clang-asan
make -j30

./ffmpeg_g -y -i poc16ffmpeg -filter_complex areverse tmp.mp4

ASAN Log:

=================================================================x
==809032==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61e000017290 at pc 0x55c70e479a45 bp 0x7f58adff8e90 sp 0x7f58adff8e88
READ of size 8 at 0x61e000017290 thread T2 (fc0)
    #0 0x55c70e479a44 in areverse_request_frame /ffmpeg/libavfilter/f_reverse.c:269:26
    #1 0x55c70e44a2f6 in ff_request_frame_to_filter /ffmpeg/libavfilter/avfilter.c:482:15
    #2 0x55c70e446560 in ff_filter_activate_default /ffmpeg/libavfilter/avfilter.c:1194:20
    #3 0x55c70e446560 in ff_filter_activate /ffmpeg/libavfilter/avfilter.c:1341:11
    #4 0x55c70e455860 in get_frame_internal /ffmpeg/libavfilter/buffersink.c:139:19
    #5 0x55c70e452ff0 in avfilter_graph_request_oldest /ffmpeg/libavfilter/avfiltergraph.c:1306:17
    #6 0x55c70e350344 in read_frames /ffmpeg/fftools/ffmpeg_filter.c:2426:15
    #7 0x55c70e346e28 in filter_thread /ffmpeg/fftools/ffmpeg_filter.c:2819:15
    #8 0x55c70e388c18 in task_wrapper /ffmpeg/fftools/ffmpeg_sched.c:2200:21
    #9 0x7f58b09e0ac2  (/lib/x86_64-linux-gnu/libc.so.6+0x94ac2) (BuildId: a43bfc8428df6623cd498c9c0caeb91aec9be4f9)
    #10 0x7f58b0a72a3f  (/lib/x86_64-linux-gnu/libc.so.6+0x126a3f) (BuildId: a43bfc8428df6623cd498c9c0caeb91aec9be4f9)

0x61e000017296 is located 0 bytes to the right of 2582-byte region [0x61e000016880,0x61e000017296)
allocated by thread T2 (fc0) here:
    #0 0x55c70e2ebf46 in __interceptor_realloc (/ffmpeg/ffmpeg_g+0x923f46) (BuildId: 8d6ccf457a75d047d11f9627d0b67208c2215c8c)
    #1 0x55c711958aee in av_realloc /ffmpeg/libavutil/mem.c:162:11
    #2 0x55c711958aee in av_fast_realloc /ffmpeg/libavutil/mem.c:513:11

Thread T2 (fc0) created by T0 here:
    #0 0x55c70e2d4f9c in __interceptor_pthread_create (/ffmpeg/ffmpeg_g+0x90cf9c) (BuildId: 8d6ccf457a75d047d11f9627d0b67208c2215c8c)
    #1 0x55c70e383161 in task_start /ffmpeg/fftools/ffmpeg_sched.c:403:11
    #2 0x55c70e3a1e68 in transcode /ffmpeg/fftools/ffmpeg.c:922:11
    #3 0x55c70e3a1e68 in main /ffmpeg/fftools/ffmpeg.c:1050:11
    #4 0x7f58b0975d8f  (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f) (BuildId: a43bfc8428df6623cd498c9c0caeb91aec9be4f9)

SUMMARY: AddressSanitizer: heap-buffer-overflow /ffmpeg/libavfilter/f_reverse.c:269:26 in areverse_request_frame
Shadow bytes around the buggy address:
  0x0c3c7fffae00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3c7fffae10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3c7fffae20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3c7fffae30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3c7fffae40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c3c7fffae50: 00 00[06]fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3c7fffae60: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3c7fffae70: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3c7fffae80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3c7fffae90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3c7fffaea0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==809032==ABORTING

ffmpeg version:

# ./ffmpeg -version
ffmpeg version N-113007-g8d24a28d06 Copyright (c) 2000-2023 the FFmpeg developers
built with Ubuntu clang version 14.0.0-1ubuntu1.1
configuration: --cc=clang --cxx=clang++ --ld=clang --enable-debug --toolchain=clang-asan
libavutil      58. 34.100 / 58. 34.100
libavcodec     60. 35.100 / 60. 35.100
libavformat    60. 18.100 / 60. 18.100
libavdevice    60.  4.100 / 60.  4.100
libavfilter     9. 14.100 /  9. 14.100
libswscale      7.  6.100 /  7.  6.100
libswresample   4. 13.100 /  4. 13.100

Credit:

Discovered by Zeng Yunxiang.

Thanks for your time!

[ZengYunxiang]

POC file

[Michael Niedermayer]

Fixed by 61e73851a33f0b4cb7662f8578a4695e77bd3c19