https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120196
--- Comment #2 from anlauf at gcc dot gnu.org ---
(In reply to anlauf from comment #1)
> Here's a testcase that fails under valgrind:
>
> program p
> implicit none
> character(:), allocatable :: a(:), s
> allocate (character(16) :: a(10), s)
> a(:)(:) = ""
> s(:) = "*"
> print *, findloc (a, s, dim=1, back=.true.)
> deallocate (a, s)
> end program p
It also fails with -fsanitize=address here:
=================================================================
==25625==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x7c4060ae0030 at pc 0x7f6061ee5e13 bp 0x7fff5db66110 sp 0x7fff5db658d0
READ of size 16 at 0x7c4060ae0030 thread T0
#0 0x7f6061ee5e12 in MemcmpInterceptorCommon(void*, int (*)(void const*,
void const*, unsigned long), void const*, void const*, unsigned long)
../../../../gcc-trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:847
#1 0x7f6061ee62c1 in memcmp
../../../../gcc-trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:879
#2 0x7f6061ee62c1 in memcmp
../../../../gcc-trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:874
#3 0x0000004179fa in _gfortrani_compare_string
../../../gcc-trunk/libgfortran/intrinsics/string_intrinsics_inc.c:98
#4 0x000000404922 in _gfortran_findloc2_s1
../../../gcc-trunk/libgfortran/generated/findloc2_s1.c:54
#5 0x000000403069 in MAIN__ (/home/anlauf/gcc-bugs/a.out+0x403069)
#6 0x00000040322d in main (/home/anlauf/gcc-bugs/a.out+0x40322d)
#7 0x7f6061a40e6b in __libc_start_call_main (/lib64/libc.so.6+0x40e6b)
(BuildId: 3c23d9be9ad37c86aafb5d405431f5f140ab0d8e)
#8 0x7f6061a40f34 in __libc_start_main_alias_1 (/lib64/libc.so.6+0x40f34)
(BuildId: 3c23d9be9ad37c86aafb5d405431f5f140ab0d8e)
#9 0x000000402c20 in _start ../sysdeps/x86_64/start.S:115
0x7c4060ae0030 is located 16 bytes before 160-byte region
[0x7c4060ae0040,0x7c4060ae00e0)
allocated by thread T0 here:
#0 0x7f6061f1ff7b in malloc
../../../../gcc-trunk/libsanitizer/asan/asan_malloc_linux.cpp:67
#1 0x000000402da7 in MAIN__ (/home/anlauf/gcc-bugs/a.out+0x402da7)
SUMMARY: AddressSanitizer: heap-buffer-overflow
../../../gcc-trunk/libgfortran/intrinsics/string_intrinsics_inc.c:98 in
_gfortrani_compare_string
Shadow bytes around the buggy address:
0x7c4060adfd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7c4060adfe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7c4060adfe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7c4060adff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7c4060adff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x7c4060ae0000: fa fa fa fa fa fa[fa]fa 00 00 00 00 00 00 00 00
0x7c4060ae0080: 00 00 00 00 00 00 00 00 00 00 00 00 fa fa fa fa
0x7c4060ae0100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x7c4060ae0180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x7c4060ae0200: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x7c4060ae0280: 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
==25625==ABORTING
