From 5ef4e41918b2dffffa445d8d3a45f3dc257920dc Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 19 Sep 2018 13:11:41 -0700 Subject: [PATCH] LSM: Prepare for reorganizing "security=" logic This moves the string handling for "security=" boot parameter into a stored pointer instead of a string duplicate. This will allow easier handling of the string when switching logic to use the coming enable/disable infrastructure. Signed-off-by: Kees Cook Reviewed-by: Casey Schaufler Reviewed-by: John Johansen --- security/security.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/security/security.c b/security/security.c index b6d3456..1e1f342 100644 --- a/security/security.c +++ b/security/security.c @@ -34,9 +34,6 @@ #define MAX_LSM_EVM_XATTR 2 -/* Maximum number of letters for an LSM name string */ -#define SECURITY_NAME_MAX 10 - /* How many LSMs were built into the kernel? */ #define LSM_COUNT (__end_lsm_info - __start_lsm_info) @@ -45,9 +42,8 @@ static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain); char *lsm_names; /* Boot-time LSM user choice */ -static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] = - CONFIG_DEFAULT_SECURITY; static __initdata const char *chosen_lsm_order; +static __initdata const char *chosen_major_lsm; static __initconst const char * const builtin_lsm_order = CONFIG_LSM; @@ -138,7 +134,7 @@ static bool __init lsm_allowed(struct lsm_info *lsm) return true; /* Disabled if this LSM isn't the chosen one. */ - if (strcmp(lsm->name, chosen_lsm) != 0) + if (strcmp(lsm->name, chosen_major_lsm) != 0) return false; return true; @@ -168,6 +164,9 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) struct lsm_info *lsm; char *sep, *name, *next; + if (!chosen_major_lsm) + chosen_major_lsm = CONFIG_DEFAULT_SECURITY; + sep = kstrdup(order, GFP_KERNEL); next = sep; /* Walk the list, looking for matching LSMs. */ @@ -257,12 +256,12 @@ int __init security_init(void) } /* Save user chosen LSM */ -static int __init choose_lsm(char *str) +static int __init choose_major_lsm(char *str) { - strncpy(chosen_lsm, str, SECURITY_NAME_MAX); + chosen_major_lsm = str; return 1; } -__setup("security=", choose_lsm); +__setup("security=", choose_major_lsm); /* Explicitly choose LSM initialization order. */ static int __init choose_lsm_order(char *str) -- 2.7.4