diff --git a/fs/pidfs.c b/fs/pidfs.c
index 049352f973de38967ad35c6440b9480e7e2e2775..63f9699ebac36873d83fbf253846ae09e87b91e7 100644
--- a/fs/pidfs.c
+++ b/fs/pidfs.c
@@ -287,7 +287,6 @@ static bool pidfs_ioctl_valid(unsigned int cmd)
 	switch (cmd) {
 	case FS_IOC_GETVERSION:
 	case PIDFD_GET_CGROUP_NAMESPACE:
-	case PIDFD_GET_INFO:
 	case PIDFD_GET_IPC_NAMESPACE:
 	case PIDFD_GET_MNT_NAMESPACE:
 	case PIDFD_GET_NET_NAMESPACE:
@@ -300,6 +299,17 @@ static bool pidfs_ioctl_valid(unsigned int cmd)
 		return true;
 	}
 
+	/* Extensible ioctls require some more careful checks. */
+	switch (_IOC_NR(cmd)) {
+	case _IOC_NR(PIDFD_GET_INFO):
+		/*
+		 * Try to prevent performing a pidfd ioctl when someone
+		 * erronously mistook the file descriptor for a pidfd.
+		 * This is not perfect but will catch most cases.
+		 */
+		return (_IOC_TYPE(cmd) == _IOC_TYPE(PIDFD_GET_INFO));
+	}
+
 	return false;
 }