fix(sdmmc): Validate DMA buffer address range

Closes https://github.com/espressif/esp-idf/issues/18714

components/esp_driver_sdmmc/test_apps/sdmmc/components/sdmmc_tests/CMakeLists.txt

@@ -16,6 +16,7 @@ endif()
 
 set(priv_requires "sdmmc"
                   "esp_driver_sdmmc"
+                  "esp_psram"
                   "sdmmc_test_boards"
                   "common_test_flows"
                   "unity"

components/esp_driver_sdmmc/test_apps/sdmmc/components/sdmmc_tests/sdmmc_test_rw_sd.c

@@ -6,6 +6,7 @@
 #include <stdio.h>
 #include <stddef.h>
 #include "unity.h"
+#include "esp_psram.h"
 #include "sdmmc_cmd.h"
 #include "sdmmc_test_begin_end_sd.h"
 #include "sdmmc_test_rw_common.h"
@@ -135,6 +136,10 @@ static void do_one_sdmmc_rw_test_psram_dma_buffer(int slot, int width)
     int freq_khz = SDMMC_FREQ_HIGHSPEED;
 #if !CONFIG_SPIRAM
     TEST_IGNORE_MESSAGE("PSRAM is not enabled");
+#else
+    if (!esp_psram_is_initialized()) {
+        TEST_IGNORE_MESSAGE("PSRAM is not available");
+    }
 #endif
     sdmmc_test_sd_skip_if_board_incompatible(slot, width, freq_khz, NO_DDR, NO_EMMC);
     sdmmc_test_sd_begin(slot, width, freq_khz, 0, &card);

components/esp_driver_sdmmc/test_apps/sdmmc/main/CMakeLists.txt

@@ -1,4 +1,4 @@
-set(srcs "test_app_main.c" "test_sd_driver_resource.c")
+set(srcs "test_app_main.c" "test_sd_driver_resource.c" "test_sdmmc_buffer.c")
 
 set(priv_requires
         # tests reside in this component, also available for `sdmmc_console`

components/esp_driver_sdmmc/test_apps/sdmmc/main/test_sdmmc_buffer.c

@@ -0,0 +1,49 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdint.h>
+#include "sdkconfig.h"
+#include "unity.h"
+#include "esp_private/sd_host_buffer.h"
+#include "soc/soc.h"
+#include "esp_heap_caps.h"
+#include "esp_memory_utils.h"
+#include "esp_psram.h"
+
+#if SOC_RTC_FAST_MEM_SUPPORTED
+TEST_CASE("SDMMC rejects an RTC fast RAM DMA buffer", "[sdmmc]")
+{
+    const size_t buffer_size = 512;
+    void *internal_dma_buf = heap_caps_malloc(buffer_size, MALLOC_CAP_DMA | MALLOC_CAP_CACHE_ALIGNED);
+    const size_t offset = 0x20;
+    const void *rtc_fast_ram_buf = (const void *)(SOC_RTC_DRAM_LOW + offset);
+    TEST_ASSERT_NOT_NULL(internal_dma_buf);
+
+    TEST_ASSERT_TRUE(sd_host_check_buffer_alignment(NULL, internal_dma_buf, buffer_size));
+    TEST_ASSERT_FALSE(sd_host_check_buffer_alignment(NULL, rtc_fast_ram_buf, buffer_size));
+    TEST_ASSERT_FALSE(sd_host_check_buffer_alignment(NULL, (const void *)(UINTPTR_MAX - 255), buffer_size));
+
+    heap_caps_free(internal_dma_buf);
+}
+#endif
+
+#if CONFIG_SPIRAM && !SOC_SDMMC_PSRAM_DMA_CAPABLE
+TEST_CASE("SDMMC rejects a PSRAM buffer when PSRAM is not DMA capable", "[sdmmc]")
+{
+    const size_t buffer_size = 512;
+    if (!esp_psram_is_initialized()) {
+        TEST_IGNORE_MESSAGE("PSRAM is not available");
+    }
+
+    void *psram_buf = heap_caps_malloc(buffer_size, MALLOC_CAP_SPIRAM | MALLOC_CAP_CACHE_ALIGNED);
+    TEST_ASSERT_NOT_NULL(psram_buf);
+    TEST_ASSERT_TRUE(esp_ptr_external_ram(psram_buf));
+
+    TEST_ASSERT_FALSE(sd_host_check_buffer_alignment(NULL, psram_buf, buffer_size));
+
+    heap_caps_free(psram_buf);
+}
+#endif

components/esp_driver_sdmmc/test_apps/sdmmc/sdkconfig.defaults.esp32

@@ -0,0 +1,2 @@
+CONFIG_SPIRAM=y
+CONFIG_SPIRAM_IGNORE_NOTFOUND=y

components/esp_driver_sdmmc/test_apps/sdmmc/sdkconfig.defaults.esp32s3

@@ -0,0 +1,2 @@
+CONFIG_SPIRAM=y
+CONFIG_SPIRAM_IGNORE_NOTFOUND=y