AddressSanitizer: heap-buffer-overflow in xv_mgcsfx.c read_mgcsfx()

[mal359]

System Info: Debian Sid x86_64, GCC 13.1, xv latest master

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==1589884==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000005bbe at pc 0x7ff0140d64cb bp 0x7ffd3c9263c0 sp 0x7ffd3c925b80
READ of size 16 at 0x602000005bbe thread T0
    #0 0x7ff0140d64ca in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:933
    #1 0x7ff0140d6e28 in __interceptor_memcmp ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:964
    #2 0x7ff0140d6e28 in __interceptor_memcmp ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:959
    #3 0x561e5be27c6d in read_mgcsfx.constprop.0 (/home/matt/jasper/xv/tmp_cmake/xv/src/xv+0x264c6d) (BuildId: 262b11d9ad1aa62086c1191cd0ff61e588a69f83)
    #4 0x561e5be2a037 in init_mgcsfx (/home/matt/jasper/xv/tmp_cmake/xv/src/xv+0x267037) (BuildId: 262b11d9ad1aa62086c1191cd0ff61e588a69f83)
    #5 0x561e5be2bf9c in CreateMGCSFXW (/home/matt/jasper/xv/tmp_cmake/xv/src/xv+0x268f9c) (BuildId: 262b11d9ad1aa62086c1191cd0ff61e588a69f83)
    #6 0x561e5bc3990e in main (/home/matt/jasper/xv/tmp_cmake/xv/src/xv+0x7690e) (BuildId: 262b11d9ad1aa62086c1191cd0ff61e588a69f83)
    #7 0x7ff0139e2b89 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #8 0x7ff0139e2c44 in __libc_start_main_impl ../csu/libc-start.c:360
    #9 0x561e5bc3ca30 in _start (/home/matt/jasper/xv/tmp_cmake/xv/src/xv+0x79a30) (BuildId: 262b11d9ad1aa62086c1191cd0ff61e588a69f83)

0x602000005bbe is located 0 bytes after 14-byte region [0x602000005bb0,0x602000005bbe)
allocated by thread T0 here:
    #0 0x7ff0140ea5bf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x561e5be28300 in read_mgcsfx.constprop.0 (/home/matt/jasper/xv/tmp_cmake/xv/src/xv+0x265300) (BuildId: 262b11d9ad1aa62086c1191cd0ff61e588a69f83)

SUMMARY: AddressSanitizer: heap-buffer-overflow ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:933 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long)
Shadow bytes around the buggy address:
  0x602000005900: fa fa fd fa fa fa fd fa fa fa fd fa fa fa 02 fa
  0x602000005980: fa fa fd fa fa fa fd fa fa fa 02 fa fa fa fd fa
  0x602000005a00: fa fa 04 fa fa fa fd fa fa fa fd fa fa fa fd fa
  0x602000005a80: fa fa fd fa fa fa fd fa fa fa fd fd fa fa 04 fa
  0x602000005b00: fa fa fd fa fa fa 00 03 fa fa fd fa fa fa 00 fa
=>0x602000005b80: fa fa fd fa fa fa 00[06]fa fa fd fa fa fa fd fa
  0x602000005c00: fa fa 04 fa fa fa fd fa fa fa 00 05 fa fa fd fa
  0x602000005c80: fa fa 00 03 fa fa fd fa fa fa fa fa fa fa fa fa
  0x602000005d00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x602000005d80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x602000005e00: 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
==1589884==ABORTING

[william8000]

@mal359 If this still happens, can you provide an image that triggers it?