Red Hat has issued the third update to its flagship Red Hat Enterprise Linux 4 (RHEL) platform since last year's version release. In addition to the slew of security, feature and driver updates, and a few technology previews, are revised SELinux policy packages.
Security Enhanced Linux is one of the marquee features in RHEL 4 and is the result of an open collaboration with the U.S. National Security Agency (NSA). It locks down access control and helps to prevent privilege escalation and other permission-based attack vectors.
The SELinux improvements in RHEL 4 Update 3 enable several applications to run properly that did not do so under the previous default policy configuration. For example, Red Hat's "up2date" command, which checks the Red Hat repository for package updates, can now execute "init" scripts.
According to a Red Hat bug advisory RHBA-2006:0049-18, "init" scripts can now also use unlabeled file systems.
InfiniBand support via the OpenIB.org stack gets a technology preview in the update. The OpenIB Alliance formed back in 2004 to develop a common Linux implementation for InfiniBand configurations.
The preview in RHEL 4 Update 3 is not intended for production use, although Red Hat's Product Enhancement Advisory notes that, "as more upper-layer protocols are implemented by the OpenIB group, a fully supported release of the OpenIB Infiniband network/clustering stack is planned."
A new execution analysis technology called Frysk is also previewed in the update.
"Frysk is an execution-analysis technology implemented using native Java and C++," Red Hat's Product Enhancement Advisory states. "It is aimed at providing developers and sysadmins with the ability to both examine and analyze running multi-host, multi-process, multi-threaded systems."
Multi-CPU system hardware support is improved with support for up to 64 logical CPUs on both EM64T and AMD64 platforms. Red Hat is also including a technology preview of support on IA64 for very large system configurations.
As is typically the case in a Linux distribution update, RHEL 4 Update 3 includes a long list of driver updates and additions. Included in the list this time are updates to various SATA and iSCSI storage devices.
Red Hat releases new RHEL versions on an approximately 18-month release cycle to provide a degree of stability for enterprise users.
Red Hat's Fedora Project community Linux distribution releases new versions about every six months. Fedora Core 5 is set to be released this month.
This article was originally published on internetnews.com.