This violates -D_FORTIFY_SOURCE=2 (which is stricter than C standard), but isn't actually any buffer overflow. But using memcpy is more efficient anyway. --- dosfstools-2.11/mkdosfs/mkdosfs.c.jj 2005-12-18 14:49:16.000000000 -0500 +++ dosfstools-2.11/mkdosfs/mkdosfs.c 2005-12-18 14:49:16.000000000 -0500 @@ -805,7 +805,7 @@ setup_tables (void) /* On Atari, the first few bytes of the boot sector are assigned * differently: The jump code is only 2 bytes (and m68k machine code * :-), then 6 bytes filler (ignored), then 3 byte serial number. */ - strncpy( bs.system_id-1, "mkdosf", 6 ); + memcpy( bs.system_id-1, "mkdosf", 6 ); else strcpy (bs.system_id, "mkdosfs"); if (sectors_per_cluster)