==28051==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6220000018fd at pc 0x7f6182c3fea8 bp 0x7ffde16993d0 sp 0x7ffde16993c8
READ of size 1 at 0x6220000018fd thread T0
#0 0x7f6182c3fea7 in sixel_encode_highcolor /home/tmp/libsixel/src/tosixel.c:1361:25
#1 0x7f6182c3fea7 in sixel_encode /home/tmp/libsixel/src/tosixel.c:1509
#2 0x7f6182f6e5a4 in sixel_encoder_output_without_macro /home/tmp/libsixel/src/encoder.c:820:14
#3 0x7f6182f6e5a4 in sixel_encoder_encode_frame /home/tmp/libsixel/src/encoder.c:1050
#4 0x7f6182d2aa21 in sixel_helper_load_image_file /home/tmp/libsixel/src/loader.c:919:14
#5 0x7f6182f66a4f in sixel_encoder_encode /home/tmp/libsixel/src/encoder.c:1737:14
#6 0x51787f in main /home/tmp/libsixel/converters/img2sixel.c:457:22
#7 0x7f61812cdb96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
#8 0x41a379 in _start (/home/tmp/img2sixel+0x41a379)
0x6220000018fd is located 3 bytes to the left of 5328-byte region [0x622000001900,0x622000002dd0)
allocated by thread T0 here:
#0 0x4da230 in __interceptor_malloc (/home/tmp/img2sixel+0x4da230)
#1 0x7f6182f6e0ee in sixel_encoder_output_without_macro /home/tmp/libsixel/src/encoder.c:784:26
#2 0x7f6182f6e0ee in sixel_encoder_encode_frame /home/tmp/libsixel/src/encoder.c:1050
#3 0x7f6182d2aa21 in sixel_helper_load_image_file /home/tmp/libsixel/src/loader.c:919:14
#4 0x7f6182f66a4f in sixel_encoder_encode /home/tmp/libsixel/src/encoder.c:1737:14
#5 0x51787f in main /home/tmp/libsixel/converters/img2sixel.c:457:22
#6 0x7f61812cdb96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
SUMMARY: AddressSanitizer: heap-buffer-overflow /home/tmp/libsixel/src/tosixel.c:1361:25 in sixel_encode_highcolor
Shadow bytes around the buggy address:
0x0c447fff82c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c447fff82d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c447fff82e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c447fff82f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c447fff8300: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c447fff8310: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]
0x0c447fff8320: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c447fff8330: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c447fff8340: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c447fff8350: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c447fff8360: 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
==28051==ABORTING
img2sixel 1.8.3
There is a heap-buffer-overflow in sixel_encode_highcolor at tosixel.c:1361 please run following cmd to reproduce it.
poc ASAN LOG