openkylin
/
platform_kernel-5.15
mirror of https://gitee.com/openkylin/platform_kernel-5.15.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

LSM: Refactor "security=" in terms of enable/disable 

For what are marked as the Legacy Major LSMs, make them effectively
exclusive when selected on the "security=" boot parameter, to handle
the future case of when a previously major LSMs become non-exclusive
(e.g. when TOMOYO starts blob-sharing).

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
This commit is contained in:
Kees Cook 2018-09-19 13:32:15 -07:00
parent 5ef4e41918
commit 7e611486d9
1 changed files with 20 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
security/security.c
View File

@ -129,14 +129,6 @@ static bool __init lsm_allowed(struct lsm_info *lsm)
if (!is_enabled(lsm)) if (!is_enabled(lsm))
return false; return false;
/* Skip major-specific checks if not a major LSM. */
if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) == 0)
return true;
/* Disabled if this LSM isn't the chosen one. */
if (strcmp(lsm->name, chosen_major_lsm) != 0)
return false;
return true; return true;
} }
@ -164,8 +156,28 @@ static void __init ordered_lsm_parse(const char *order, const char *origin)
struct lsm_info *lsm; struct lsm_info *lsm;
char *sep, *name, *next; char *sep, *name, *next;
/* Process "security=", if given. */
if (!chosen_major_lsm) if (!chosen_major_lsm)
chosen_major_lsm = CONFIG_DEFAULT_SECURITY; chosen_major_lsm = CONFIG_DEFAULT_SECURITY;
if (chosen_major_lsm) {
struct lsm_info *major;
/*
* To match the original "security=" behavior, this
* explicitly does NOT fallback to another Legacy Major
* if the selected one was separately disabled: disable
* all non-matching Legacy Major LSMs.
*/
for (major = __start_lsm_info; major < __end_lsm_info;
major++) {
if ((major->flags & LSM_FLAG_LEGACY_MAJOR) &&
strcmp(major->name, chosen_major_lsm) != 0) {
set_enabled(major, false);
init_debug("security=%s disabled: %s\n",
chosen_major_lsm, major->name);
}
}
}
sep = kstrdup(order, GFP_KERNEL); sep = kstrdup(order, GFP_KERNEL);
next = sep; next = sep;