Use zero for poisoning instead of debugging value
An XCCDF Rule
Description
Instead of using the existing poison value, fill the pages with zeros. This makes it harder to
detect when errors are occurring due to sanitization but the zeroing at free means that it is
no longer necessary to write zeros when GFP_ZERO is used on allocation.
This configuration is available from kernel 4.19.
The configuration that was used to build kernel is available at /boot/config-*.
To check the configuration value for CONFIG_PAGE_POISONING_ZERO, run the following command:
grep CONFIG_PAGE_POISONING_ZERO /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 configuration helps alleviates the performance impact of poisonining.
- ID
- xccdf_org.ssgproject.content_rule_kernel_config_page_poisoning_zero
- Severity
- Medium
- References
- Updated