Disable vsyscall emulate execution only
An XCCDF Rule
Description
The kernel traps and emulates calls into the fixed vsyscall address mapping and does not allow
reads.
This configuration is available from kernel 5.3.
The configuration that was used to build kernel is available at /boot/config-*.
To check the configuration value for CONFIG_LEGACY_VSYSCALL_XONLY, run the following command:
grep CONFIG_LEGACY_VSYSCALL_XONLY /boot/config-*
Configs with value 'n' are not explicitly set in the file, so either commented lines or no
lines 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
Disabling this mitigates certain uses of the vsyscall area as an ASLR-bypassing buffer.
- ID
- xccdf_org.ssgproject.content_rule_kernel_config_legacy_vsyscall_xonly
- Severity
- Medium
- References
- Updated