When more than one security module is exporting data to
audit and networking sub-systems a single 32 bit integer
is no longer sufficient to represent the data. Add a
structure to be used instead.
The lsmblob structure is currently an array of
u32 "secids". There is an entry for each of the
security modules built into the system that would
use secids if active. The system assigns the module
a "slot" when it registers hooks. If modules are
compiled in but not registered there will be unused
slots.
A new lsm_id structure, which contains the name
of the LSM and its slot number, is created. There
is an instance for each LSM, which assigns the name
and passes it to the infrastructure to set the slot.
Reviewed-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
Acked-by: Stephen Smalley <sds@xxxxxxxxxxxxx>
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
include/linux/lsm_hooks.h | 12 ++++++--
include/linux/security.h | 58 ++++++++++++++++++++++++++++++++++++
security/apparmor/lsm.c | 7 ++++-
security/commoncap.c | 7 ++++-
security/loadpin/loadpin.c | 8 ++++-
security/lockdown/lockdown.c | 7 ++++-
security/safesetid/lsm.c | 8 ++++-
security/security.c | 28 +++++++++++++----
security/selinux/hooks.c | 8 ++++-
security/smack/smack_lsm.c | 7 ++++-
security/tomoyo/tomoyo.c | 8 ++++-
security/yama/yama_lsm.c | 7 ++++-
12 files changed, 148 insertions(+), 17 deletions(-)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c2b1af29a8f0..7eb808cde051 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2077,6 +2077,14 @@ struct security_hook_heads {
#endif
} __randomize_layout;
+/*
+ * Information that identifies a security module.
+ */
+struct lsm_id {
+ const char *lsm; /* Name of the LSM */
+ int slot; /* Slot in lsmblob if one is allocated */
+};
+
/*
* Security module hook list structure.
* For use with generic list macros for common operations.
@@ -2085,7 +2093,7 @@ struct security_hook_list {
struct hlist_node list;
struct hlist_head *head;
union security_list_options hook;
- char *lsm;
+ struct lsm_id *lsmid;
} __randomize_layout;
/*
@@ -2114,7 +2122,7 @@ extern struct security_hook_heads security_hook_heads;
extern char *lsm_names;
extern void security_add_hooks(struct security_hook_list *hooks, int count,
- char *lsm);
+ struct lsm_id *lsmid);
#define LSM_FLAG_LEGACY_MAJOR BIT(0)
#define LSM_FLAG_EXCLUSIVE BIT(1)
diff --git a/include/linux/security.h b/include/linux/security.h
index 3e8d4bacd59d..b74dc70088ca 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -128,6 +128,64 @@ enum lockdown_reason {
LOCKDOWN_CONFIDENTIALITY_MAX,
};
+/*
+ * Data exported by the security modules
+ *
+ * Any LSM that provides secid or secctx based hooks must be included.
+ */
+#define LSMBLOB_ENTRIES ( \
+ (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0))
+
+struct lsmblob {
+ u32 secid[LSMBLOB_ENTRIES];
+};
+
+#define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */
+#define LSMBLOB_NEEDED -2 /* Slot requested on initialization */
+#define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */
+
+/**
+ * lsmblob_init - initialize an lsmblob structure.
+ * @blob: Pointer to the data to initialize
+ * @secid: The initial secid value
+ *
+ * Set all secid for all modules to the specified value.
+ */
+static inline void lsmblob_init(struct lsmblob *blob, u32 secid)
+{
+ int i;
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++)
+ blob->secid[i] = secid;
+}
+
+/**
+ * lsmblob_is_set - report if there is an value in the lsmblob
+ * @blob: Pointer to the exported LSM data
+ *
+ * Returns true if there is a secid set, false otherwise
+ */
+static inline bool lsmblob_is_set(struct lsmblob *blob)
+{
+ struct lsmblob empty = {};
+
+ return !!memcmp(blob, &empty, sizeof(*blob));
+}
+
+/**
+ * lsmblob_equal - report if the two lsmblob's are equal
+ * @bloba: Pointer to one LSM data
+ * @blobb: Pointer to the other LSM data
+ *
+ * Returns true if all entries in the two are equal, false otherwise
+ */
+static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
+{
+ return !memcmp(bloba, blobb, sizeof(*bloba));
+}
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 61b24f4eb355..146d75e5e021 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1147,6 +1147,11 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
.lbs_sock = sizeof(struct aa_sk_ctx),
};
+static struct lsm_id apparmor_lsmid __lsm_ro_after_init = {
+ .lsm = "apparmor",
+ .slot = LSMBLOB_NEEDED
+};
+
static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
@@ -1847,7 +1852,7 @@ static int __init apparmor_init(void)
goto buffers_out;
}
security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
- "apparmor");
+ &apparmor_lsmid);
/* Report that AppArmor successfully initialized */
apparmor_initialized = 1;
diff --git a/security/commoncap.c b/security/commoncap.c
index f4ee0ae106b2..9dcfd2a0e891 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -1339,6 +1339,11 @@ int cap_mmap_file(struct file *file, unsigned long reqprot,
#ifdef CONFIG_SECURITY
+static struct lsm_id capability_lsmid __lsm_ro_after_init = {
+ .lsm = "capability",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(capable, cap_capable),
LSM_HOOK_INIT(settime, cap_settime),
@@ -1363,7 +1368,7 @@ static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
static int __init capability_init(void)
{
security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks),
- "capability");
+ &capability_lsmid);
return 0;
}
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index ee5cb944f4ad..86317e78899f 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -180,6 +180,11 @@ static int loadpin_load_data(enum kernel_load_data_id id)
return loadpin_read_file(NULL, (enum kernel_read_file_id) id);
}
+static struct lsm_id loadpin_lsmid __lsm_ro_after_init = {
+ .lsm = "loadpin",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security),
LSM_HOOK_INIT(kernel_read_file, loadpin_read_file),
@@ -227,7 +232,8 @@ static int __init loadpin_init(void)
pr_info("ready to pin (currently %senforcing)\n",
enforce ? "" : "not ");
parse_exclude();
- security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin");
+ security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks),
+ &loadpin_lsmid);
return 0;
}
diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index b2f87015d6e9..91662325e450 100644
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -102,6 +102,11 @@ static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(locked_down, lockdown_is_locked_down),
};
+static struct lsm_id lockdown_lsmid __lsm_ro_after_init = {
+ .lsm = "landlock",
