[FFmpeg-trac] #8310(undetermined:new): heap-buffer-overflow at libavfilter/vf_lagfun.c:141

[FFmpeg]

#8310: heap-buffer-overflow at libavfilter/vf_lagfun.c:141
-------------------------------------+-------------------------------------
             Reporter:  Suhwan       |                     Type:  defect
               Status:  new          |                 Priority:  important
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:  asan         |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 There is a heap-buffer-overflow at libavfilter/vf_lagfun.c:141 in
 lagfun_frame16
 I compiled ffmpeg with "--toolchain=clang-asan" to check the memory
 corruption and attached log file.
 How to reproduce:
 {{{
 % ffmpeg_g -stream_loop 25 -y -i $PoC -filter_complex lagfun -target vcd
 -loglevel 0 tmp.mv

 ffmpeg version N-95450-g1d479300cb 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
 }}}

 Here's ASAN log

 {{{
 =================================================================
 ==22005==ERROR: AddressSanitizer: heap-buffer-overflow on address
 0x7fc59e02101e at pc 0x000000e45858 bp 0x7fc5a8327b60 sp 0x7fc5a8327b58
 WRITE of size 2 at 0x7fc59e02101e thread T60
     #0 0xe45857 in lagfun_frame16 ffmpeg/libavfilter/vf_lagfun.c:141:24
     #1 0x943139 in worker_func ffmpeg/libavfilter/pthread.c:50:15
     #2 0x86b8122 in run_jobs ffmpeg/libavutil/slicethread.c:61:9
     #3 0x86b5a8d in thread_worker ffmpeg/libavutil/slicethread.c:85:13
     #4 0x4eb9de in __asan::AsanThread::ThreadStart(unsigned long,
 __sanitizer::atomic_uintptr_t*) (ffmpeg_g+0x4eb9de)
     #5 0x7fc5cb2606da in start_thread (/lib/x86_64-linux-
 gnu/libpthread.so.0+0x76da)
     #6 0x7fc5ca96588e in clone /build/glibc-
 OTsEL5/glibc-2.27/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95

 0x7fc59e02101f is located 0 bytes to the right of 1280031-byte region
 [0x7fc59dee8800,0x7fc59e02101f)
 allocated by thread T0 here:
     #0 0x4de9e8 in posix_memalign (ffmpeg_g+0x4de9e8)
     #1 0x85c4251 in av_malloc ffmpeg/libavutil/mem.c:87:9
     #2 0x852b181 in av_buffer_alloc ffmpeg/libavutil/buffer.c:72:12
     #3 0x852b181 in av_buffer_allocz ffmpeg/libavutil/buffer.c:85
     #4 0x852f9a6 in pool_alloc_buffer ffmpeg/libavutil/buffer.c:313:26
     #5 0x852f9a6 in av_buffer_pool_get ffmpeg/libavutil/buffer.c:349
     #6 0x91b6ed in ff_frame_pool_get ffmpeg/libavfilter/framepool.c:222:29
     #7 0x15d8e4c in ff_default_get_video_buffer
 ffmpeg/libavfilter/video.c:90:13
     #8 0xe3e4f5 in filter_frame ffmpeg/libavfilter/vf_lagfun.c:188:11
     #9 0x827129 in ff_filter_activate_default
 ffmpeg/libavfilter/avfilter.c:1084:11
     #10 0x827129 in ff_filter_activate ffmpeg/libavfilter/avfilter.c:1443
     #11 0x86ffd5 in push_frame ffmpeg/libavfilter/buffersrc.c:187:15
     #12 0x86ffd5 in av_buffersrc_add_frame_internal
 ffmpeg/libavfilter/buffersrc.c:261
     #13 0x86ea62 in av_buffersrc_add_frame_flags
 ffmpeg/libavfilter/buffersrc.c:170:16
     #14 0x666467 in ifilter_send_frame ffmpeg/fftools/ffmpeg.c:2186:11
     #15 0x666467 in send_frame_to_filters ffmpeg/fftools/ffmpeg.c:2260
     #16 0x6076c6 in decode_video ffmpeg/fftools/ffmpeg.c:2459:11
     #17 0x6076c6 in process_input_packet ffmpeg/fftools/ffmpeg.c:2613
     #18 0x641d1d in process_input ffmpeg/fftools/ffmpeg.c:4269:23
     #19 0x5e71b7 in transcode_step ffmpeg/fftools/ffmpeg.c:4628:11
     #20 0x5e71b7 in transcode ffmpeg/fftools/ffmpeg.c:4682
     #21 0x5db6bb in main ffmpeg/fftools/ffmpeg.c:4884:9
     #22 0x7fc5ca865b96 in __libc_start_main /build/glibc-
 OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310

 Thread T60 created by T0 here:
     #0 0x436f80 in pthread_create (ffmpeg_g+0x436f80)
     #1 0x86b4c79 in avpriv_slicethread_create
 ffmpeg/libavutil/slicethread.c:147:19

 SUMMARY: AddressSanitizer: heap-buffer-overflow
 ffmpeg/libavfilter/vf_lagfun.c:141:24 in lagfun_frame16
 Shadow bytes around the buggy address:
   0x0ff933bfc1b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x0ff933bfc1c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x0ff933bfc1d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x0ff933bfc1e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   0x0ff933bfc1f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 =>0x0ff933bfc200: 00 00 00[07]fa fa fa fa fa fa fa fa fa fa fa fa
   0x0ff933bfc210: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x0ff933bfc220: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x0ff933bfc230: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x0ff933bfc240: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
   0x0ff933bfc250: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
 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
 ==22005==ABORTING

 }}}
 Please confirm.
 Thanks

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8310>
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