this instance is integer-overflowable, but we cannot keep hand-auditing every instance (or apathetically ignoring these issues) when the simple calloc idiom is better in the presence of a good calloc(). It is simply unfeasible to always enter correct range checks before the aggregate size calculation, just go find some 4000 lines of code, REPAIR THEM ALL, then come back and tell me I am wrong. This only works on systems where calloc() does the integer overflow check, but if your system doesn't do this, you need to ask your vendor WHY THEY ARE 10 YEARS BEHIND IN BEST PRACTICE? This is the kind of problem that needs to be solved at the right layer. malloc integer-overflow was implicated in the 2002 OpenSSH hole. OpenSSH and much other code is now written to use calloc(), for instance OpenSSH has 103 calls to it. We feel safer with our use of calloc(). It is a natural approach for us to use calloc(). How safe do you feel on systems which lack that range check in their calloc()? Good writeup from 2006: http://undeadly.org/cgi?action=article&sid=20060330071917