From 1612fd9ac3af88f57d83f5e37fc9aac49c2ded72 Mon Sep 17 00:00:00 2001
From: Weixie Cui <cuiweixie@gmail.com>
Date: Sun, 22 Mar 2026 02:52:52 +0800
Subject: [PATCH] dnn: fix BatchNorm bias blob index in validation

When hasBias is true, CV_Assert must reference blobs[biasBlobIndex], not blobs[weightsBlobIndex], for the bias tensor.
---
 modules/dnn/src/layers/batch_norm_layer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/dnn/src/layers/batch_norm_layer.cpp b/modules/dnn/src/layers/batch_norm_layer.cpp
index 3cdbdc222b..745ca57a85 100644
--- a/modules/dnn/src/layers/batch_norm_layer.cpp
+++ b/modules/dnn/src/layers/batch_norm_layer.cpp
@@ -84,7 +84,7 @@ public:
         if( hasBias )
         {
             CV_Assert((size_t)biasBlobIndex < blobs.size());
-            const Mat& b = blobs[weightsBlobIndex];
+            const Mat& b = blobs[biasBlobIndex];
             CV_Assert(b.isContinuous() && b.type() == CV_32F && b.total() == (size_t)n);
         }