diff --git a/sys/compat/linuxkpi/common/src/linux_idr.c b/sys/compat/linuxkpi/common/src/linux_idr.c
--- a/sys/compat/linuxkpi/common/src/linux_idr.c
+++ b/sys/compat/linuxkpi/common/src/linux_idr.c
@@ -178,6 +178,14 @@
 {
 	struct idr_layer *il, *iln;
 
+	/*
+	 * This idr can be reused, and this function might be called multiple times
+	 * without a idr_init(). Check if this is the case.  If we do not do this
+	 * then the mutex will panic while asserting that it is valid.
+	 */
+	if (mtx_initialized(&idr->lock) == 0)
+		return;
+
 	idr_remove_all(idr);
 	mtx_lock(&idr->lock);
 	for (il = idr->free; il != NULL; il = iln) {
@@ -802,4 +810,5 @@
 {
 	idr_destroy(&ida->idr);
 	free(ida->free_bitmap, M_IDR);
+	ida->free_bitmap = NULL;
 }