On 9/20/2018 9:23 AM, Kees Cook wrote:
> Provide a way to reorder LSM initialization using the new "lsm.order="
> comma-separated list of LSMs. Any LSMs not listed will be added in builtin
> order.
>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 5 +++++
> security/security.c | 15 ++++++++++++++-
> 2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 32d323ee9218..5ac4c1056ffa 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2276,6 +2276,11 @@
>
> lsm.debug [SECURITY] Enable LSM initialization debugging output.
>
> + lsm.order=lsm1,...,lsmN
> + [SECURITY] Choose order of LSM initialization. Any
> + builtin LSMs not listed here will be implicitly
> + added to the list in builtin order.
Added at the end of the list, or beginning of the list?
> +
> machvec= [IA-64] Force the use of a particular machine-vector
> (machvec) in a generic kernel.
> Example: machvec=hpzx1_swiotlb
> diff --git a/security/security.c b/security/security.c
> index 063ee2466e58..4db194f81419 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -43,6 +43,7 @@ static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain);
> char *lsm_names;
> /* Boot-time LSM user choice */
> static __initdata const char *chosen_major_lsm;
> +static __initdata const char *chosen_lsm_order;
>
> static __initconst const char * const builtin_lsm_order = CONFIG_LSM_ORDER;
>
> @@ -136,11 +137,15 @@ static void __init parse_lsm_order(const char *order, const char *origin)
> kfree(sep);
> }
>
> -/* Populate ordered LSMs list from builtin list of LSMs. */
> +/* Populate ordered LSMs list from commandline and builtin list of LSMs. */
> static void __init prepare_lsm_order(void)
> {
> struct lsm_info *lsm;
>
> + /* Parse order from commandline, if present. */
> + if (chosen_lsm_order)
> + parse_lsm_order(chosen_lsm_order, "cmdline");
> +
> /* Parse order from builtin list. */
> parse_lsm_order(builtin_lsm_order, "builtin");
>
> @@ -264,6 +269,14 @@ static int __init choose_major_lsm(char *str)
> }
> __setup("security=", choose_major_lsm);
>
> +/* Explicitly choose LSM initialization order. */
> +static int __init choose_lsm_order(char *str)
> +{
> + chosen_lsm_order = str;
> + return 1;
> +}
> +__setup("lsm.order=", choose_lsm_order);
> +
> /* Enable LSM order debugging. */
> static int __init enable_debug(char *str)
> {
