[PATCH v1 3/8] LSM: Identify the process attributes for each module

Casey Schaufler
2022-10-25T18:47:34Z

Add an integer member "features" to the struct lsm_id which
identifies the API related data associated with each security
module. The initial set of features maps to information that
has traditionaly been available in /proc/self/attr.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
include/linux/lsm_hooks.h | 1 +
include/uapi/linux/lsm.h | 14 ++++++++++++++
security/apparmor/lsm.c | 1 +
security/selinux/hooks.c | 2 ++
security/smack/smack_lsm.c | 1 +
5 files changed, 19 insertions(+)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index dd4b4d95a172..46b2aa6a677e 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1608,6 +1608,7 @@ struct security_hook_heads {
struct lsm_id {
const char *lsm; /* Name of the LSM */
int id; /* LSM ID */
+ int features; /* Set of LSM features */
};

/*
diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h
index d5bcbb9375df..61e13b1b9ece 100644
--- a/include/uapi/linux/lsm.h
+++ b/include/uapi/linux/lsm.h
@@ -29,4 +29,18 @@
#define LSM_ID_BPF 42
#define LSM_ID_LANDLOCK 43

+/*
+ * LSM_ATTR_XXX values identify the /proc/.../attr entry that the
+ * context represents. Not all security modules provide all of these
+ * values. Some security modules provide none of them.
+ */
+/* clang-format off */
+#define LSM_ATTR_CURRENT (1UL << 0)
+#define LSM_ATTR_EXEC (1UL << 1)
+#define LSM_ATTR_FSCREATE (1UL << 2)
+#define LSM_ATTR_KEYCREATE (1UL << 3)
+#define LSM_ATTR_PREV (1UL << 4)
+#define LSM_ATTR_SOCKCREATE (1UL << 5)
+/* clang-format on */
+
#endif /* _UAPI_LINUX_LSM_H */
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index b859b1af6c75..77260026fda0 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1206,6 +1206,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
static struct lsm_id apparmor_lsmid __lsm_ro_after_init = {
.lsm = "apparmor",
.id = LSM_ID_APPARMOR,
+ .features = LSM_ATTR_CURRENT | LSM_ATTR_PREV | LSM_ATTR_EXEC,
};

static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5fcce36267bd..107b944e5d45 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7018,6 +7018,8 @@ static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
.lsm = "selinux",
.id = LSM_ID_SELINUX,
+ .features = LSM_ATTR_CURRENT | LSM_ATTR_EXEC | LSM_ATTR_FSCREATE |
+ LSM_ATTR_KEYCREATE | LSM_ATTR_PREV | LSM_ATTR_SOCKCREATE,
};

/*
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index c7ba80e20b8d..12ff27c00fe6 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4791,6 +4791,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
static struct lsm_id smack_lsmid __lsm_ro_after_init = {
.lsm = "smack",
.id = LSM_ID_SMACK,
+ .features = LSM_ATTR_CURRENT,
};

static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
--
2.37.3