https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83823
--- Comment #2 from Thomas Koenig <tkoenig at gcc dot gnu.org> --- -fsanitize=address gives: ==21482==ERROR: AddressSanitizer: global-buffer-overflow on address 0x000000402624 at pc 0x7f6d755ede76 bp 0x7ffed65778c0 sp 0x7ffed6577070 READ of size 5 at 0x000000402624 thread T0 #0 0x7f6d755ede75 in __interceptor_memmove ../../../../trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:720 #1 0x40134d in gfcbug145 /tmp/foo.f90:14 #2 0x402323 in main /tmp/foo.f90:17 #3 0x7f6d745f6f49 in __libc_start_main (/lib64/libc.so.6+0x20f49) #4 0x400c89 in _start (/tmp/a.out+0x400c89) 0x000000402624 is located 60 bytes to the left of global variable '*.LC6' defined in 'foo.f90' (0x402660) of size 5 0x000000402624 is located 0 bytes to the right of global variable '*.LC5' defined in 'foo.f90' (0x402620) of size 4 SUMMARY: AddressSanitizer: global-buffer-overflow ../../../../trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:720 in __interceptor_memmove Shadow bytes around the buggy address: 0x000080078470: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080078480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080078490: 00 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 0x0000800784a0: f9 f9 f9 f9 00 06 f9 f9 f9 f9 f9 f9 00 00 00 00 0x0000800784b0: f9 f9 f9 f9 05 f9 f9 f9 f9 f9 f9 f9 05 f9 f9 f9 =>0x0000800784c0: f9 f9 f9 f9[04]f9 f9 f9 f9 f9 f9 f9 05 f9 f9 f9 0x0000800784d0: f9 f9 f9 f9 00 00 00 00 f9 f9 f9 f9 00 00 00 00 0x0000800784e0: f9 f9 f9 f9 00 00 00 04 f9 f9 f9 f9 00 00 00 00 0x0000800784f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080078500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080078510: 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 This is the print *, pack (obstyp% name, mask) line.