Add a security hook that will allow an LSM to rule on whether or not a
watch may be set on a mount.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: James Morris <jamorris@xxxxxxxxxxxxxxxxxxx>
cc: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
cc: Stephen Smalley <sds@xxxxxxxxxxxxx>
cc: linux-security-module@xxxxxxxxxxxxxxx
---
include/linux/lsm_hook_defs.h | 3 +++
include/linux/lsm_hooks.h | 6 ++++++
include/linux/security.h | 8 ++++++++
security/security.c | 7 +++++++
4 files changed, 24 insertions(+)
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index af998f93d256..f6eaf8bd617b 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -264,6 +264,9 @@ LSM_HOOK(int, 0, post_notification, const struct cred *w_cred,
#if defined(CONFIG_SECURITY) && defined(CONFIG_KEY_NOTIFICATIONS)
LSM_HOOK(int, 0, watch_key, struct key *key)
#endif /* CONFIG_SECURITY && CONFIG_KEY_NOTIFICATIONS */
+#ifdef CONFIG_MOUNT_NOTIFICATIONS
+LSM_HOOK(int, 0, watch_mount, struct watch *watch, struct path *path)
+#endif
#ifdef CONFIG_SECURITY_NETWORK
LSM_HOOK(int, 0, unix_stream_connect, struct sock *sock, struct sock *other,
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 95b7c1d32062..56275145b91d 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1468,6 +1468,12 @@
* from a key or keyring.
* @key: The key to watch.
*
+ * @watch_mount:
+ * Check to see if a process is allowed to watch for mount topology change
+ * notifications on a mount subtree.
+ * @watch: The watch object
+ * @path: The root of the subtree to watch.
+ *
* Security hooks for using the eBPF maps and programs functionalities through
* eBPF syscalls.
*
diff --git a/include/linux/security.h b/include/linux/security.h
index 0a0a03b36a3b..318fdfe7f4d6 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1314,6 +1314,14 @@ static inline int security_watch_key(struct key *key)
return 0;
}
#endif
+#if defined(CONFIG_SECURITY) && defined(CONFIG_MOUNT_NOTIFICATIONS)
+int security_watch_mount(struct watch *watch, struct path *path);
+#else
+static inline int security_watch_mount(struct watch *watch, struct path *path)
+{
+ return 0;
+}
+#endif
#ifdef CONFIG_SECURITY_NETWORK
diff --git a/security/security.c b/security/security.c
index 70a7ad357bc6..3cdf5039f727 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2067,6 +2067,13 @@ int security_watch_key(struct key *key)
}
#endif
+#ifdef CONFIG_MOUNT_NOTIFICATIONS
+int security_watch_mount(struct watch *watch, struct path *path)
+{
+ return call_int_hook(watch_mount, 0, watch, path);
+}
+#endif
+
#ifdef CONFIG_SECURITY_NETWORK
int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk)
