{"description": "This config disables the vsyscall mapping at all. Attempts to use the vsyscalls will be reported to\ndmesg, so that either old or malicious userspace programs can be identified.\nThis configuration is available from kernel 4.4.\n\nThe configuration that was used to build kernel is available at <tt>/boot/config-*</tt>.\n    To check the configuration value for <tt>CONFIG_LEGACY_VSYSCALL_NONE</tt>, run the following command:\n    <tt>grep CONFIG_LEGACY_VSYSCALL_NONE /boot/config-*</tt>\n    \n    For each kernel installed, a line with value \"y\" should be returned.\n    ", "rationale": "This will eliminate any risk of ASLR bypass due to the vsyscall fixed address mapping.", "severity": "medium", "references": {"anssi": ["R15"]}, "control_references": {"anssi": ["R15"]}, "components": [], "identifiers": {}, "ocil_clause": "the kernel was not built with the required value", "ocil": "To determine the config value the kernel was built with, run the following command:\n    <pre>$ grep CONFIG_LEGACY_VSYSCALL_NONE /boot/config.*</pre>\n    \n    For each kernel installed, a line with value \"y\" should be returned.\n    ", "oval_external_content": null, "fixtext": "", "checktext": "", "vuldiscussion": "", "srg_requirement": "", "warnings": [{"general": "There is no remediation for this besides re-compiling the kernel with the appropriate value for the config."}], "conflicts": [], "requires": [], "policy_specific_content": {}, "platform": null, "platforms": [], "sce_metadata": {}, "inherited_platforms": ["system_with_kernel"], "cpe_platform_names": [], "inherited_cpe_platform_names": ["system_with_kernel"], "bash_conditional": null, "fixes": {}, "title": "Disable vsyscall mapping", "definition_location": "/aptdata/openscap/scap-security-guide/linux_os/guide/system/kernel_build_config/kernel_config_legacy_vsyscall_none/rule.yml", "template": {"name": "kernel_build_config", "vars": {"config": "CONFIG_LEGACY_VSYSCALL_NONE", "value": "y"}, "backends": {}}}