Avoid speculative indirect branches in kernel
An XCCDF Rule
Description
Compile kernel with the retpoline compiler options to guard against kernel-to-user data leaks by avoiding speculative indirect branches. Requires a compiler with -mindirect-branch=thunk-extern support for full protection. The kernel may run slower. The configuration that was used to build kernel is available at/boot/config-*.
To check the configuration value for CONFIG_RETPOLINE, run the following command:
grep CONFIG_RETPOLINE /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 is required to enable protection against Spectre v2.
- ID
- xccdf_org.ssgproject.content_rule_kernel_config_retpoline
- Severity
- Medium
- References
- Updated