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| author |   James Morris <jmorris@namei.org> | 2017-02-15 00:17:24 +1100 |
|---|---|---|
| committer |   James Morris <james.l.morris@oracle.com> | 2017-03-06 11:00:12 +1100 |
| commit | dd0859dccbe291cf8179a96390f5c0e45cb9af1d (patch) | |
| tree | e7a2b67dfdb2beaa07d42a314eb142289599d381 | |
| parent | selinux: fix kernel BUG on prlimit(..., NULL, NULL) (diff) | |
| download | linux-dev-dd0859dccbe291cf8179a96390f5c0e45cb9af1d.tar.xz linux-dev-dd0859dccbe291cf8179a96390f5c0e45cb9af1d.zip | |
security: introduce CONFIG_SECURITY_WRITABLE_HOOKS
Subsequent patches will add RO hardening to LSM hooks, however, SELinux
still needs to be able to perform runtime disablement after init to handle
architectures where init-time disablement via boot parameters is not feasible.
Introduce a new kernel configuration parameter CONFIG_SECURITY_WRITABLE_HOOKS,
and a helper macro __lsm_ro_after_init, to handle this case.
Signed-off-by: James Morris <james.l.morris@oracle.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | include/linux/lsm_hooks.h | 7 | ||||
| -rw-r--r-- | security/Kconfig | 5 | ||||
| -rw-r--r-- | security/selinux/Kconfig | 6 |
3 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index ba3049f05aea..1aa63335de9e 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1920,6 +1920,13 @@ static inline void security_delete_hooks(struct security_hook_list *hooks, } #endif /* CONFIG_SECURITY_SELINUX_DISABLE */ +/* Currently required to handle SELinux runtime hook disable. */ +#ifdef CONFIG_SECURITY_WRITABLE_HOOKS +#define __lsm_ro_after_init +#else +#define __lsm_ro_after_init __ro_after_init +#endif /* CONFIG_SECURITY_WRITABLE_HOOKS */ + extern int __init security_module_enable(const char *module); extern void __init capability_add_hooks(void); #ifdef CONFIG_SECURITY_YAMA diff --git a/security/Kconfig b/security/Kconfig index d900f47eaa68..3ff1bf91080e 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -31,6 +31,11 @@ config SECURITY If you are unsure how to answer this question, answer N. +config SECURITY_WRITABLE_HOOKS + depends on SECURITY + bool + default n + config SECURITYFS bool "Enable the securityfs filesystem" help diff --git a/security/selinux/Kconfig b/security/selinux/Kconfig index ea7e3efbe0f7..8af7a690eb40 100644 --- a/security/selinux/Kconfig +++ b/security/selinux/Kconfig @@ -40,6 +40,7 @@ config SECURITY_SELINUX_BOOTPARAM_VALUE config SECURITY_SELINUX_DISABLE bool "NSA SELinux runtime disable" depends on SECURITY_SELINUX + select SECURITY_WRITABLE_HOOKS default n help This option enables writing to a selinuxfs node 'disable', which @@ -50,6 +51,11 @@ config SECURITY_SELINUX_DISABLE portability across platforms where boot parameters are difficult to employ. + NOTE: selecting this option will disable the '__ro_after_init' + kernel hardening feature for security hooks. Please consider + using the selinux=0 boot parameter instead of enabling this + option. + If you are unsure how to answer this question, answer N. config SECURITY_SELINUX_DEVELOP |