LSM: Add /sys/kernel/security/lsm

I am still tired of having to find indirect ways to determine
what security modules are active on a system. I have added
/sys/kernel/security/lsm, which contains a comma separated
list of the active security modules. No more groping around
in /proc/filesystems or other clever hacks.

Unchanged from previous versions except for being updated
to the latest security next branch.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
This commit is contained in:
Casey Schaufler
2017-01-18 17:09:05 -08:00
committed by James Morris
parent 3ccb76c5df
commit d69dece5f5
11 changed files with 82 additions and 17 deletions

View File

@ -32,6 +32,7 @@
/* Maximum number of letters for an LSM name string */
#define SECURITY_NAME_MAX 10
char *lsm_names;
/* Boot-time LSM user choice */
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
CONFIG_DEFAULT_SECURITY;
@ -78,6 +79,22 @@ static int __init choose_lsm(char *str)
}
__setup("security=", choose_lsm);
static int lsm_append(char *new, char **result)
{
char *cp;
if (*result == NULL) {
*result = kstrdup(new, GFP_KERNEL);
} else {
cp = kasprintf(GFP_KERNEL, "%s,%s", *result, new);
if (cp == NULL)
return -ENOMEM;
kfree(*result);
*result = cp;
}
return 0;
}
/**
* security_module_enable - Load given security module on boot ?
* @module: the name of the module
@ -97,6 +114,27 @@ int __init security_module_enable(const char *module)
return !strcmp(module, chosen_lsm);
}
/**
* security_add_hooks - Add a modules hooks to the hook lists.
* @hooks: the hooks to add
* @count: the number of hooks to add
* @lsm: the name of the security module
*
* Each LSM has to register its hooks with the infrastructure.
*/
void __init security_add_hooks(struct security_hook_list *hooks, int count,
char *lsm)
{
int i;
for (i = 0; i < count; i++) {
hooks[i].lsm = lsm;
list_add_tail_rcu(&hooks[i].list, hooks[i].head);
}
if (lsm_append(lsm, &lsm_names) < 0)
panic("%s - Cannot get early memory.\n", __func__);
}
/*
* Hook list operation macros.
*