[GPU] Prevent unsafe in-place crop optimization for 2D-to-1D bbox splits

src/plugins/intel_gpu/src/graph/include/reshape_inst.h

@@ -79,6 +79,7 @@ struct typed_program_node<reshape> : public typed_program_node_base<reshape> {
                 axis == 1 &&
                 !input_pshape[1].is_dynamic() &&
                 input_pshape[1].get_length() == 1 &&
+                prim->output_partial_shape.size() >= 2 &&
                 prim->output_partial_shape.size() + 1 == input_pshape.size();
             if (!is_axis1_size1_squeeze)
                 return false;
@@ -134,8 +135,15 @@ struct typed_program_node<reshape> : public typed_program_node_base<reshape> {
         // shape tensor (not a compile-time constant) for the Reshape second input,
         // leaving output_pattern empty — requiring it would incorrectly block this
         // case even though conditions 1–3 are fully sufficient.
+        // Only the TransposeSplitMatcher pattern is safe: crop [batch, 1, H, S] → reshape
+        // drops the size-1 dim → [batch, H, S].  The output must stay ≥ 2D so that the
+        // downstream CM/OCL kernel still has at least one inner stride to carry the offset.
+        // A 2D → 1D squeeze (e.g. NMS bbox-coord split [-1, 4] → [-1, 1] → [-1]) does NOT
+        // meet this condition and must not be optimized — its downstream arithmetic kernels
+        // are compiled without dynamic-padding support.
         if (axis == 1 && !input_pshape[1].is_dynamic() && input_pshape[1].get_length() == 1) {
-            if (prim->output_partial_shape.size() + 1 == input_pshape.size()) {
+            if (prim->output_partial_shape.size() >= 2 &&
+                prim->output_partial_shape.size() + 1 == input_pshape.size()) {
                 return true;
             }
         }

src/plugins/intel_gpu/src/plugin/transformations/transpose_fusion.cpp

@@ -586,8 +586,8 @@ TransposeSplitMatcher::TransposeSplitMatcher() {
         // This produces 3 outputs of shape [-1, 1, H, S] instead of [1, -1, H, S]
         auto new_split_axis = ov::op::v0::Constant::create(ov::element::i64, ov::Shape{}, {1});
         auto new_split = std::make_shared<ov::op::v1::Split>(input_node, new_split_axis, split->get_num_splits());
-         ov::copy_runtime_info(m.get_matched_nodes(), new_split);
-         ov::replace_node(split, new_split);
+        ov::copy_runtime_info(m.get_matched_nodes(), new_split);
+        ov::replace_node(split, new_split);
         return true;
     };
 

src/plugins/intel_gpu/tests/unit/passes/prepare_buffer_fusing_test.cpp

@@ -1014,6 +1014,52 @@ TEST(prepare_buffer_fusing, do_runtime_in_place_crop_skips_non_propagatable_resh
     ASSERT_FALSE(crop_inst->can_be_optimized());
 }
 
+TEST(prepare_buffer_fusing, in_place_crop_axis1_rank_reducing_to_1d_not_optimized) {
+    auto& engine = get_test_engine();
+
+    constexpr int64_t rows = 8;
+    const auto input_layout_dynamic = layout{ov::PartialShape{-1, 4}, data_types::f32, format::bfyx};
+    auto input_memory = engine.allocate_memory({{rows, 4}, data_types::f32, format::bfyx});
+    auto axis_memory = engine.allocate_memory({{}, data_types::i64, format::bfyx});
+    auto split_lengths_memory = engine.allocate_memory({{4}, data_types::i64, format::bfyx});
+    auto scale_memory = engine.allocate_memory({{1}, data_types::f32, format::bfyx});
+
+    set_values<float>(input_memory, std::vector<float>(rows * 4, 1.0f));
+    set_values<int64_t>(axis_memory, {1});
+    set_values<int64_t>(split_lengths_memory, {1, 1, 1, 1});
+    set_values<float>(scale_memory, {1.0f});
+
+    topology topology(
+        input_layout("input", input_layout_dynamic),
+        data("axis", axis_memory),
+        data("split_lengths", split_lengths_memory),
+        data("scale", scale_memory),
+        crop("bbox_coordinate", {input_info("input"), input_info("axis"), input_info("split_lengths")},
+             tensor(1),
+             tensor(0),
+             crop_ngraph_op_mode::variadic_split,
+             0,
+             1),
+        reshape("bbox_coordinate_1d",
+                input_info("bbox_coordinate"),
+                false,
+                {-1},
+                ov::PartialShape{-1},
+                reshape::reshape_mode::base),
+        eltwise("bbox_coordinate_scale", {input_info("bbox_coordinate_1d"), input_info("scale")}, eltwise_mode::prod),
+        reorder("output", input_info("bbox_coordinate_scale"), format::bfyx, data_types::f32));
+
+    ExecutionConfig config = get_test_default_config(engine);
+    config.set_property(ov::intel_gpu::allow_new_shape_infer(true));
+    config.set_property(ov::intel_gpu::optimize_data(true));
+
+    network network(engine, topology, config);
+    network.set_input_data("input", input_memory);
+    network.execute();
+
+    ASSERT_FALSE(network.get_primitive("bbox_coordinate")->can_be_optimized());
+}
+
 TEST(prepare_buffer_fusing, in_place_crop_dynamic_reshape_unsqueeze) {
     auto& engine = get_test_engine();