mgmt: fs: Add security warning

Add a warning in fs mgmt option about security risks.

Signed-off-by: Flavio Ceolin <[email protected]>

Author: Flavio Ceolin

ext/lib/mgmt/mcumgr/cmd/fs_mgmt/Kconfig

@@ -16,11 +16,16 @@
 # Under the License.
 
 menuconfig MCUMGR_CMD_FS_MGMT
-    bool "Enable mcumgr handlers for file management"
+    bool "Enable mcumgr handlers for file management (insecure)"
     depends on FILE_SYSTEM
     help
       Enables mcumgr handlers for file management
 
+      This option allows mcumgr clients to access anything in the
+      file system, including application-stored secrets like
+      private keys. Use of this feature in production is strongly
+      discouraged.
+
 if MCUMGR_CMD_FS_MGMT
 config FS_MGMT_UL_CHUNK_SIZE
     int "Maximum chunk size for file uploads"