[GPU] Fix: Prevent out-of-bounds read in dequantize merge

src/plugins/intel_gpu/src/graph/graph_optimizer/prepare_quantization.cpp

@@ -368,23 +368,32 @@ void prepare_quantization::prepare_dequantize_merge(program& p, eltwise_node& el
         if (!valid_scale_node)
             continue;
 
-        bool same_params = true;
-        for (size_t i = 1; i < eltwise_node.get_dependencies().size(); i++) {
-            auto mem0 = get_scale_shift_mem(eltwise_dep, i);
-            auto mem1 = get_scale_shift_mem(eltwise_node, i);
+      //...
+       bool same_params = true;
+       for (size_t i = 1; i < eltwise_node.get_dependencies().size(); i++) {
+        auto mem0 = get_scale_shift_mem(eltwise_dep, i);
+       auto mem1 = get_scale_shift_mem(eltwise_node, i);
+
+        //  FIXED: Check sizes first!
+        if (mem0->get_layout().bytes_count() != mem1->get_layout().bytes_count()) {
+            same_params = false;
+            // No need to check the rest of the dependencies if one is already different
+            break; 
+        }
 
             mem_lock<uint8_t, mem_lock_type::read> mem0_lock{mem0, stream};
             mem_lock<uint8_t, mem_lock_type::read> mem1_lock{mem1, stream};
-            auto ptr0 = mem0_lock.data();
-            auto ptr1 = mem1_lock.data();
-
-            for (size_t j = 0; j < mem0->get_layout().bytes_count(); j++) {
-                if (ptr0[j] != ptr1[j]) {
-                    same_params = false;
-                    break;
-                }
+             auto ptr0 = mem0_lock.data();
+              auto ptr1 = mem1_lock.data();
+
+        // Now this loop is safe
+         for (size_t j = 0; j < mem0->get_layout().bytes_count(); j++) {
+               if (ptr0[j] != ptr1[j]) {
+                   same_params = false;
+                       break;
+                 }
             }
-
+//...
             // Avoid mem0 and mem1's memory are inplace, but they have different layout.
             if (!mem0->get_layout().get_partial_shape().compatible(mem1->get_layout().get_partial_shape())) {
                 same_params = false;