diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 690ae991a80f..66c328d1c14e 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1846,8 +1846,21 @@ static int cxl_region_attach_auto(struct cxl_region *cxlr,
 	 * this means that userspace can view devices in the wrong position
 	 * before the region activates, and must be careful to understand when
 	 * it might be racing region autodiscovery.
+	 *
+	 * The endpoint decoder will be recorded into the first free slot of
+	 * the target array.
 	 */
-	pos = p->nr_targets;
+	for (pos = 0; pos < p->interleave_ways; pos++) {
+		if (!p->targets[pos])
+			break;
+	}
+
+	if (pos == p->interleave_ways) {
+		dev_err(&cxlr->dev, "%s: unable to find a free target slot\n",
+			dev_name(&cxled->cxld.dev));
+		return -ENXIO;
+	}
+
 	p->targets[pos] = cxled;
 	cxled->pos = pos;
 	cxled->state = CXL_DECODER_STATE_AUTO_STAGED;