Syscall param write(buf) contains uninitialised or unaddressable byte(s)
   at 0x........: write (in /...libc...)
   by 0x........: __libc_start_main (...libc...)
   by 0x........: ...
 Address 0x........ is 0 bytes inside a block of size 10 alloc'd
   at 0x........: malloc (vg_replace_malloc.c:...)
   by 0x........: main (fwrite.c:6)