C - Dumping cores with call to fclose()

My code is segfaulting and I have no idea what is wrong. I've simplified it as far as I can but still can't find a problem.

C File test.c:

#include <stdlib.h>
#include <stdio.h>

struct container {
   void *A[3], *B[3], *C[3], *D[3];
   int x, y, z;
};

int main (int argc, char* argv[]) {
   struct container *cont = malloc (sizeof cont);
   FILE* fh = fopen( argv[1], "r" );
   if( fh == NULL ) return 0;
   fscanf(fh, "%d %d", &cont->y,  &cont->z);
   fclose( fh );
   free( cont );

   return 0;
}

Contents of test.txt

1 1

Executing and running through gdb:

$ gcc --version
gcc (Ubuntu/Linaro 4.8.1-10ubuntu9) 4.8.1
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -g test.c && gdb a.out 
GNU gdb (GDB) 7.6.1-ubuntu
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /home/dberg/ITX/Cells/test/a.out...done.
(gdb) break 26
Breakpoint 1 at 0x400739: file test.c, line 26.
(gdb) run test.txt
Starting program: /home/dberg/ITX/Cells/test/a.out test.txt

Breakpoint 1, main (argc=2, argv=0x7fffffffdf48) at test.c:26
26         fclose( fh );
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
__GI___libc_free (mem=0x1) at malloc.c:2892
2892    malloc.c: No such file or directory.
(gdb)

Deleting any one of the unused struct members allows the code to execute without error. Moving any of the unused struct members to the end of the struct or decreasing the size of any 1 or all arrays also allows the code to execute successfully. The presence of the fscanf() call is also necessary for the segfault

Where is my syntax wrong and why is the size of the struct so critical to this bug?

Solution

There's a * missing in struct container *cont = malloc (sizeof cont);, you need sizeof *cont.