From: sramacher@debian.org   
      
   Control: forwarded -1 https://code.ffmpeg.org/FFmpeg/FFmpeg/issues/21756   
      
   On 2026-02-13 23:54:51 +0100, Joachim Bauch wrote:   
   > Package: ffmpeg   
   > Version: 7:8.0.1-3+b1   
   > Severity: normal   
   > X-Debbugs-Cc: debian-loongarch@lists.debian.org   
   > User: debian-loongarch@lists.debian.org   
   > Usertags: loong64   
   > Control: block 1127385 by -1   
   >    
   > Dear Maintainer,   
   >    
   > ffmpeg segfaults in "buffer_pool_flush" when called from the kvazaar test   
   "test_invalid_input.sh" (see #1127385).   
      
   Forwarded upstream.   
      
   Cheers   
      
   >    
   > These are information to reproduce and some of my first findings.   
   >    
   > Command:   
   > ffmpeg -f lavfi -i mandelbrot=size=1x65 -vframes 1 -pix_fmt yuv420p -f   
   yuv4mpegpipe /tmp/tmp.TfM9llmcRd   
   >    
   > Output (tested in virtual machine to reproduce issue from buildd):   
   > ----------   
   > ffmpeg version 8.0.1-3+b1 Copyright (c) 2000-2025 the FFmpeg developers   
   >   built with gcc 15 (Debian 15.2.0-12)   
   >   configuration: --prefix=/usr --extra-version=3+b1 --toolchain=hardened   
   --libdir=/usr/lib/loongarch64-linux-gnu --incdir=/usr/include/lo   
   ngarch64-linux-gnu --arch=loong64 --enable-gpl --disable-stripping   
   --disable-pocketsphinx --disable-libcaca --   
   disable-libmfx --disable-omx --enable-gnutls --enable-libaom --enable-libass   
   --enable-libbs2b --enable-libcdio --enable-libcodec2 --enable-libdav1d   
   --enable-libflite --enable-libfontconfig --enable-libfreetype --   
   nable-libfribidi --enable-libglslang --   
   enable-libgme --enable-libgsm --enable-libharfbuzz --enable-libmp3lame   
   --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus   
   --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr   
   --enable-libspeex --enable-   
   libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis   
   --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2   
   --enable-libxvid --enable-libzimg --enable-openal --enable-opencl   
   --enable-opengl --disable-sndio --disable-libvpl --   
   enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint   
   --enable-frei0r --enable-ladspa --enable-libbluray --enable-libdvdnav   
   --enable-libdvdread --enable-libjack --enable-libjxl --enable-libpulse   
   --enable-librabbitmq --enable-librist -   
   -enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libx264   
   --enable-libzmq --enable-libzvbi --enable-lv2 --enable-sdl2 --en   
   ble-libplacebo --enable-librav1e --enable-librsvg --enable-shared   
   >   libavutil      60.  8.100 / 60.  8.100   
   >   libavcodec     62. 11.100 / 62. 11.100   
   >   libavformat    62.  3.100 / 62.  3.100   
   >   libavdevice    62.  1.100 / 62.  1.100   
   >   libavfilter    11.  4.100 / 11.  4.100   
   >   libswscale      9.  1.100 /  9.  1.100   
   >   libswresample   6.  1.100 /  6.  1.100   
   > Input #0, lavfi, from 'mandelbrot=size=1x65':   
   >   Duration: N/A, start: 0.000000, bitrate: N/A   
   >   Stream #0:0: Video: wrapped_avframe, rgb0, 1x65 [SAR 1:1 DAR 1:65], 25   
   fps, 25 tbr, 25 tbn   
   > Stream mapping:   
   >   Stream #0:0 -> #0:0 (wrapped_avframe (native) -> wrapped_avframe (native))   
   > Press [q] to stop, [?] for help   
   > Output #0, yuv4mpegpipe, to '/tmp/tmp.TfM9llmcRd':   
   >   Metadata:   
   >     encoder         : Lavf62.3.100   
   >   Stream #0:0: Video: wrapped_avframe, yuv420p(progressive), 1x65 [SAR 1:1   
   DAR 1:65], q=2-31, 200 kb/s, 25 fps, 25 tbn   
   >     Metadata:   
   >       encoder         : Lavc62.11.100 wrapped_avframe   
   > qemu: uncaught target signal 11 (Segmentation fault) - core dumped   
   > Segmentation fault (core dumped)   
   > ----------   
   >    
   > I attached a remote gdb and got this stack trace:   
   > ----------   
   > Thread 2 received signal SIGSEGV, Segmentation fault.   
   > [Switching to Thread 92632.92650]   
   > 0x00007fd9d8e509a4 in ?? () from target:/usr/lib/loongarch64-l   
   nux-gnu/libc.so.6   
   > (gdb) bt   
   > #0  0x00007fd9d8e509a4 in ?? () from target:/usr/lib/loongarch   
   4-linux-gnu/libc.so.6   
   > #1  0x00007fd9d8e50c7c in ?? () from target:/usr/lib/loongarch   
   4-linux-gnu/libc.so.6   
   > #2  0x00007fd9c90fc9dc in buffer_pool_flush (pool=0x7fd9ac0021e0) at   
   src/libavutil/buffer.c:308   
   > #3  av_buffer_pool_uninit (ppool=) at src/libav   
   til/buffer.c:338   
   > #4  0x00007fd9d982359c in ff_frame_pool_uninit (pool=) at   
   src/libavfilter/framepool.c:291   
   > #5  ff_frame_pool_uninit (pool=0x7fd9ac002d78) at src/libavfil   
   er/framepool.c:283   
   > #6  0x00007fd9d97f2bf4 in link_free (link=0x7fd9bc8433f8) at s   
   c/libavfilter/avfilter.c:207   
   > #7  free_link (link=) at src/libavfilter/avfilter.c:791   
   > #8  0x00007fd9d97f46d0 in avfilter_free (filter=0x7fd9ac002880) at   
   src/libavfilter/avfilter.c:815   
   > #9  0x00007fd9d97f757c in avfilter_graph_free (graphp=0x7fd9bc8434c8) at   
   src/libavfilter/avfiltergraph.c:128   
   > #10 0x00007fd9dad81768 in ?? ()   
   > #11 0x00007fd9dad94488 in ?? ()   
   > #12 0x00007fd9d8e3e504 in ?? () from target:/usr/lib/loongarch   
   4-linux-gnu/libc.so.6   
   > #13 0x00007fd9d8ebb350 in ?? () from target:/usr/lib/loongarch   
   4-linux-gnu/libc.so.6   
   > (gdb) f 2   
   > #2  0x00007fd9c90fc9dc in buffer_pool_flush (pool=0x7fd9ac0021e0) at   
   src/libavutil/buffer.c:308   
   > 308	in src/libavutil/buffer.c   
   > (gdb) p *buf   
   > $1 = {data = 0x7fd9ac07e0e0 "\244", opaque = 0x0, free = 0x7fd9c90fbdc0   
   , pool = 0x7fd9ac0021e0, next = 0x7fd9ac011660, buffer   
   = {   
   >     data = 0x0, size = 0, refcount = 0, free = 0x0, opaque = 0x0, flags = 0,   
   flags_internal = 0}}   
   > ----------   
   >    
   > Thanks,   
   >   Joachim   
   >    
   >    
   > -- System Information:   
   > Debian Release: forky/sid   
   >   APT prefers unstable-debug   
   >   APT policy: (500, 'unstable-debug'), (500, 'unstable')   
   > Architecture: loong64 (loongarch64)   
   >    
   > Kernel: Linux 5.19.0 (SMP w/4 CPU threads)   
   > Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set   
   > Shell: /bin/sh linked to /usr/bin/dash   
   > Init: unable to detect   
   >    
   > Versions of packages ffmpeg depends on:   
   > ii  libavcodec62    7:8.0.1-3+b1   
   > ii  libavdevice62   7:8.0.1-3+b1   
   > ii  libavfilter11   7:8.0.1-3+b1   
   > ii  libavformat62   7:8.0.1-3+b1   
   > ii  libavutil60     7:8.0.1-3+b1   
      
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