From 42994ee3cd7298b27698daa6848ed7168e72d056 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Fri, 10 Mar 2023 09:53:59 +0100 Subject: security: Introduce LSM_ORDER_LAST and set it for the integrity LSM Introduce LSM_ORDER_LAST, to satisfy the requirement of LSMs needing to be last, e.g. the 'integrity' LSM, without changing the kernel command line or configuration. Also, set this order for the 'integrity' LSM. While not enforced, this is the only LSM expected to use it. Similarly to LSM_ORDER_FIRST, LSMs with LSM_ORDER_LAST are always enabled and put at the end of the LSM list, if selected in the kernel configuration. Setting one of these orders alone, does not cause the LSMs to be selected and compiled built-in in the kernel. Finally, for LSM_ORDER_MUTABLE LSMs, set the found variable to true if an LSM is found, regardless of its order. In this way, the kernel would not wrongly report that the LSM is not built-in in the kernel if its order is LSM_ORDER_LAST. Fixes: 79f7865d844c ("LSM: Introduce "lsm=" for boottime LSM selection") Signed-off-by: Roberto Sassu Acked-by: Mimi Zohar Signed-off-by: Paul Moore --- security/integrity/iint.c | 1 + security/security.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) (limited to 'security') diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 8638976f7990..b97eb59e0e32 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -182,6 +182,7 @@ static int __init integrity_iintcache_init(void) DEFINE_LSM(integrity) = { .name = "integrity", .init = integrity_iintcache_init, + .order = LSM_ORDER_LAST, }; diff --git a/security/security.c b/security/security.c index e6c275fff001..b808e1b86551 100644 --- a/security/security.c +++ b/security/security.c @@ -285,9 +285,9 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) bool found = false; for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { - if (lsm->order == LSM_ORDER_MUTABLE && - strcmp(lsm->name, name) == 0) { - append_ordered_lsm(lsm, origin); + if (strcmp(lsm->name, name) == 0) { + if (lsm->order == LSM_ORDER_MUTABLE) + append_ordered_lsm(lsm, origin); found = true; } } @@ -307,6 +307,12 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) } } + /* LSM_ORDER_LAST is always last. */ + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if (lsm->order == LSM_ORDER_LAST) + append_ordered_lsm(lsm, " last"); + } + /* Disable all LSMs not in the ordered list. */ for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { if (exists_ordered_lsm(lsm)) -- cgit v1.2.3