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Randomize slab freelist

An XCCDF Rule

Description

Randomizes the freelist order used on creating new pages. This configuration is available from kernel 5.9, but may be available if backported by distros. The configuration that was used to build kernel is available at /boot/config-*. To check the configuration value for CONFIG_SLAB_FREELIST_RANDOM, run the following command: grep CONFIG_SLAB_FREELIST_RANDOM /boot/config-* For each kernel installed, a line with value "y" should be returned.

warning alert: Warning

There is no remediation for this besides re-compiling the kernel with the appropriate value for the config.

Rationale

This security feature reduces the predictability of the kernel slab allocator against heap overflows.

ID
xccdf_org.ssgproject.content_rule_kernel_config_slab_freelist_random
Severity
Medium
References
Updated