[Bug fortran/112828] Abort with malloc(): corrupted top size

["anlauf at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112828

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-12-03
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |wrong-code
                 CC|                            |anlauf at gcc dot gnu.org

--- Comment #6 from anlauf at gcc dot gnu.org ---
I get this crash with all gfortran versions (>= 7) on x86_64-pc-linux-gnu.
Sometimes optimization needs to be enabled to see this.

Replacing in reallocate the line

    character(LEN(array)), allocatable :: array_new(:)

with the actual (constant) length fixes the issue, e.g.

    character(LEN=64), allocatable :: array_new(:)

This may be a hint.

In my tests the stat variable only needs to be accessed by the line

    if (PRESENT(stat))

it needs not be set explicitly.

Compiling with -fsanitize=address gives at runtime:

- when compiled with -O0:

==30489==ERROR: AddressSanitizer: requested allocation size 0x515f9880000
(0x515f9881000 after adjustments for alignment, red zones etc.) exceeds maximum
supported size of 0x10000000000 (thread T0)
    #0 0x1457e8eb4527 in malloc
../../../../gcc-trunk/libsanitizer/asan/asan_malloc_linux.cpp:69
...

- with -Og and higher:

==30533==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x502000000071 at pc 0x152c5cbc8a79 bp 0x7fff0a124100 sp 0x7fff0a1238c0
WRITE of size 64 at 0x502000000071 thread T0
...

(details depend on optimization level).