[refpolicy] How to handle glibc-triggered behavior?

[sven.vermeulen@siphos.be (Sven Vermeulen)]

glibc's malloc implementation, in multithreaded applications, might read
/proc/sys/vm/overcommit_memory to check if the heap can be shrunk or not
(when the allocated memory is part of the non-main arena). That means that
read access to sysctl_vm_t becomes a wide request.

Not granting privileges might result in different memory behavior, where the
system administrator might have tuned/tweaked memory allocations on Linux,
but malloc() ignoring this due to SELinux denying access to the settings.

I'm wondering how to properly tackle this. Granting this on a per-domain
level is probably not manageable, but granting this for all domains (through
the "domain" attribute) might be overshooting.

Are there specific risks that I should take into account when granting read
access to sysctl_vm_t?

Wkr,
	Sven Vermeulen