user limits for 'security'?

From: LA Walsh (
Date: Mon Jun 25 2001 - 14:26:16 EST

I've seen some people saying that user-limits are an essential part of a
secure system to prevent local DoS attacks. Given that, should
a system call like 'fork' return -EPERM if the user has reached their

My local manpage (SuSE 7.2 system) says this under fork:

       EAGAIN fork cannot allocate sufficient memory to copy the
              parent's page tables and allocate a task structure
              for the child.
    Should the man page be updated to reflect that EAGAIN is returned
when the user has reached their limit? From a user-monitoring point
of view, it might be security relevant to know if a EAGAIN is being
returned because the system really is low on resources or if it
is a user hitting their limit.

The above thoughts and            | I know I don't know the opinions
writings are my own.              | of every part of my company. :-)
L A Walsh, law at         | Sr Eng, Trust Technology
01-650-933-5338                   | Core Linux, SGI

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This archive was generated by hypermail 2b29 : Sat Jun 30 2001 - 21:00:12 EST