base: stability fixes — acpid EC, inputd, block driver, ipcd UDS, netstack loopback, ptyd, ramfs, randd, scheme-utils blocking

drivers/inputd/src/main.rs

@@ -383,7 +383,11 @@ impl SchemeSync for InputScheme {
                 log::error!("display tried to write");
                 return Err(SysError::new(EINVAL));
             }
-            Handle::Producer => {}
+            Handle::Producer { .. } => {
+                // Producers send input events TO the inputd daemon, not the
+                // other way around. Writing to a Producer handle is invalid.
+                return Err(SysError::new(EINVAL));
+            }
             Handle::SchemeRoot => return Err(SysError::new(EBADF)),
         }