Doing one of these things may introduce a security vulnerability, depending on the rest of your environment. Some programs that use select(2) are known to assu

Doing one of these things may introduce a security vulnerability, depending on the rest of your environment. Some programs that use select(2) are known to assume that FD_SETSIZE is at least the maximum number of file descriptors available (instead of checking FD_SETSIZE). This lack of bounds checking may lead to a stack or heap overflow and a security vulnerability. More recently, if you build with fortified glibc options, then you'll get automatic bounds checking, but do you know that your own daemons are built this way? This is an example of why it's not a good idea to arbitrarily change a list of default settings system-wide without understanding the implications. The defaults have not been changed for a reason; otherwise distributions would already ship with these changes. References: https://lists.ubuntu.com/archives/ubuntu-devel/2010-September/031446.html https://lists.ubuntu.com/archives/ubuntu-devel/2010-Septembe... http://www.outflux.net/blog/archives/2014/06/13/5-year-old-glibc-select-weakness-fixed/ http://www.outflux.net/blog/archives/2014/06/13/5-year-old-g...