astcenc -c $PoC /dev/null 6x6 -medium
Encoding settings:

2D Block size: 6x6 (3.56 bpp)
3D Block size: 6x6x1 (3.56 bpp)
Radius for mean-and-stdev calculations: 0 texels
RGB power: 1
RGB base-weight: 1
RGB local-mean weight: 0
RGB local-stdev weight: 0
RGB mean-and-stdev mixing across color channels: 0
Alpha power: 1
Alpha base-weight: 1
Alpha local-mean weight: 0
Alpha local-stdev weight: 0
RGB weights scale with alpha: disabled
Color channel relative weighting: R=1 G=1 B=1 A=1
Block-artifact suppression parameter : 0
Number of distinct partitionings to test: 25 (preset)
PSNR decibel limit: 2D: 40.529411 3D: 40.529411 (preset)
1->2 partition limit: 1.200000
Dual-plane color-correlation cutoff: 0.750000 (preset)
Block Mode Percentile Cutoff: 75.000000 (preset)
Max refinement iterations: 2 (preset)
Thread count : 8 (autodetected)

=================================================================
==15504==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fff00ef8040 at pc 0x0000004ae78a bp 0x7fff00ef43b0 sp 0x7fff00ef43a0
WRITE of size 1 at 0x7fff00ef8040 thread T0
    #0 0x4ae789 in build_huffman /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1009
    #1 0x4b9af3 in process_marker /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1478
    #2 0x4ba85d in decode_jpeg_header /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1609
    #3 0x4c2440 in decode_jpeg_header /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1605
    #4 0x4c2440 in decode_jpeg_image /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1625
    #5 0x4c2440 in load_jpeg_image /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1816
    #6 0x4c2440 in stbi_jpeg_load /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1912
    #7 0x4d55be in stbi_load_main /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:536
    #8 0x4dc009 in stbi_load_from_file /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:571
    #9 0x4dc009 in stbi_load /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:562
    #10 0x4877b9 in load_image_with_stb(char const*, int, int*) /home/dungnguyen/gueb-testing/astc-encoder/Source/astc_stb_tga.cpp:66
    #11 0x46bff0 in astc_codec_load_image(char const*, int, int*) /home/dungnguyen/gueb-testing/astc-encoder/Source/astc_image_load_store.cpp:1328
    #12 0x49a3dd in astc_main(int, char**) /home/dungnguyen/gueb-testing/astc-encoder/Source/astc_toplevel.cpp:2329
    #13 0x7fe73da5082f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #14 0x402738 in _start (/home/dungnguyen/PoCs/astc-encoder_5ff4d86/astcenc-asan+0x402738)

Address 0x7fff00ef8040 is located in stack of thread T0 at offset 14704 in frame
    #0 0x4c1bbf in stbi_jpeg_load /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1909

  This frame has 5 object(s):
    [32, 64) 'coutput'
    [96, 224) 'data'
    [256, 384) 'data'
    [416, 608) 'res_comp'
    [640, 14704) 'j' <== Memory access at offset 14704 overflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow /home/dungnguyen/gueb-testing/astc-encoder/Source/stb_image.c:1009 build_huffman
Shadow bytes around the buggy address:
  0x1000601d6fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000601d6fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000601d6fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000601d6fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000601d6ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x1000601d7000: 00 00 00 00 00 00 00 00[f4]f4 f3 f3 f3 f3 00 00
  0x1000601d7010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000601d7020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000601d7030: f1 f1 f1 f1 00 00 00 00 f2 f2 f2 f2 00 00 00 06
  0x1000601d7040: f2 f2 f2 f2 04 f4 f4 f4 f3 f3 f3 f3 00 00 00 00
  0x1000601d7050: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 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
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  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
==15504==ABORTING