Based on kernel version 3.9. Page generated on 2013-05-02 23:14 EST.
1 Linux Security Module framework 2 ------------------------------- 3 4 The Linux Security Module (LSM) framework provides a mechanism for 5 various security checks to be hooked by new kernel extensions. The name 6 "module" is a bit of a misnomer since these extensions are not actually 7 loadable kernel modules. Instead, they are selectable at build-time via 8 CONFIG_DEFAULT_SECURITY and can be overridden at boot-time via the 9 "security=..." kernel command line argument, in the case where multiple 10 LSMs were built into a given kernel. 11 12 The primary users of the LSM interface are Mandatory Access Control 13 (MAC) extensions which provide a comprehensive security policy. Examples 14 include SELinux, Smack, Tomoyo, and AppArmor. In addition to the larger 15 MAC extensions, other extensions can be built using the LSM to provide 16 specific changes to system operation when these tweaks are not available 17 in the core functionality of Linux itself. 18 19 Without a specific LSM built into the kernel, the default LSM will be the 20 Linux capabilities system. Most LSMs choose to extend the capabilities 21 system, building their checks on top of the defined capability hooks. 22 For more details on capabilities, see capabilities(7) in the Linux 23 man-pages project. 24 25 Based on http://kerneltrap.org/Linux/Documenting_Security_Module_Intent, 26 a new LSM is accepted into the kernel when its intent (a description of 27 what it tries to protect against and in what cases one would expect to 28 use it) has been appropriately documented in Documentation/security/. 29 This allows an LSM's code to be easily compared to its goals, and so 30 that end users and distros can make a more informed decision about which 31 LSMs suit their requirements. 32 33 For extensive documentation on the available LSM hook interfaces, please 34 see include/linux/security.h.