[ fallen@kaci : ~ ] $ ./vortex0 
Received: 4
*** glibc detected *** ./vortex0: free(): invalid pointer: 0xbfc816c8 ***
======= Backtrace: =========
/lib/libc.so.6[0xb7e9ce22]
/lib/libc.so.6(__libc_free+0x82)[0xb7e9e462]
./vortex0[0x80485bd]
/lib/libc.so.6(__libc_start_main+0xdc)[0xb7e5087c]
./vortex0[0x8048461]
======= Memory map: ========
08048000-08049000 r-xp 00000000 03:03 176622     /home/fallen/vortex0
08049000-0804a000 rw-p 00000000 03:03 176622     /home/fallen/vortex0
b7d00000-b7d21000 rw-p b7d00000 00:00 0 
b7d21000-b7e00000 ---p b7d21000 00:00 0 
b7e3a000-b7e3b000 rw-p b7e3a000 00:00 0 
b7e3b000-b7f4f000 r-xp 00000000 03:03 2462255    /lib/libc-2.4.so
b7f4f000-b7f51000 r--p 00113000 03:03 2462255    /lib/libc-2.4.so
b7f51000-b7f53000 rw-p 00115000 03:03 2462255    /lib/libc-2.4.so
b7f53000-b7f56000 rw-p b7f53000 00:00 0 
b7f5f000-b7f68000 r-xp 00000000 03:03 3073281    /usr/lib/gcc/i686-pc-linux-gnu/4.1.1/libgcc_s.so.1
b7f68000-b7f69000 rw-p 00009000 03:03 3073281    /usr/lib/gcc/i686-pc-linux-gnu/4.1.1/libgcc_s.so.1
b7f69000-b7f6b000 rw-p b7f69000 00:00 0 
b7f6b000-b7f85000 r-xp 00000000 03:03 2462053    /lib/ld-2.4.so
b7f85000-b7f86000 r--p 00019000 03:03 2462053    /lib/ld-2.4.so
b7f86000-b7f87000 rw-p 0001a000 03:03 2462053    /lib/ld-2.4.so
bfc6f000-bfc85000 rw-p bfc6f000 00:00 0          [stack]
ffffe000-fffff000 ---p 00000000 00:00 0          [vdso]
Aborted
[ fallen@kaci : ~ ] $